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Esters

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  • dropped_pie
    Carbon and methanol (snore) have had more than their share of posts in this newsgroup. Esters, on the other hand, are a subject that gets far less attention
    Message 1 of 10 , Mar 31, 2005
    • 0 Attachment
      Carbon and methanol (snore) have had more than their share of posts
      in this newsgroup. Esters, on the other hand, are a subject that gets
      far less attention than it should. I feel there is too much focus on
      ethanol and water, and not the properties of the impurities we are
      really trying to remove. My still already removes more than enough
      water - I have to add water back before I use it's output so clearly
      removing water is not my main objective. Everything seems to hinge on
      the assumption that if your still is good at separating alcohol and
      water then it must be good at removing everything else. This
      assumption is loose at best and ignores the fact that with a little
      encouragement some of the worst impurities will remove themselves.

      Esters are flavour compounds responsible for many of the
      characteristic tastes we know very well:

      Propyl acetate (Pears)
      Octyl acetate (Oranges)
      Isoamyl acetate (Banana)
      Ethyl butyrate (Pineapple)
      Butyl acetate (Apple)
      Methyl trans-cinnamate (Strawberry)
      Ethyl cinnamate(Cinnamon)

      (See http://www.leffingwell.com/esters.htm. There are many others and
      a web search will turn up many more if you're interested.)

      Esters are the product of a reaction between an organic acid and an
      alcohol. Read the back of a wine bottle you'll see wine described as
      tasting of all sorts of different fruit (except grapes, of course
      because any fool can do that). Yeast, by its very nature, produces a
      range of organic acids and a range of alcohols during the
      fermentation process. These combine to form a range of esters
      responsible (along with other chemicals) for the flavours in wine
      that aren't in the original grape juice. This is where the interests
      of a winemaker differ from someone trying to make clean neutral
      spirits - winemakers see ester formation as desirable. Yeast makers
      even advertise their yeasts on how good they are at producing damn
      esters.

      The problem with esters is that a little goes such a long way. Most
      have detection thresholds measured in parts per billion (ppb). Ethyl
      butyrate – the fruity pineapple ester listed above - has an odour
      detection threshold in water of 1ppb. As a comparison, ethanol in air
      has an odour detection threshold of about 50 parts per million (ppm).
      In other words, it's odour is 50,000 times more powerful than
      ethanol. For those of you obsessed by percentages, your distillate
      could be 99.9999999% ethyl butyrate free and you'd still be able to
      smell the damn stuff. Great if that's what you want, bad if you don't.

      The ester of the most relevance to home distilling is ethyl acetate.
      Ethanol oxidises to form acetic acid. Acetic acid and ethanol react
      to form ethyl acetate. It's no real surprise that you are going to
      end up with some of this stuff in your brew - yeast puts it there.
      The good news is its odour detection level is a relatively high for
      an ester at 5000 ppb (or 0.0005%); the bad news is it has a nasty
      solvent-like smell you're probably already familiar with. And there's
      more bad news…

      By itself, it boils at 77 degrees, which is pretty close to the
      boiling point of ethanol. It forms azeotropes with both ethanol and
      water, and another when all three of them are mixed together
      (although all at mixture ratios you are never likely to see). I have
      heard many claims that ethyl acetate can be effectively removed by a
      still. It's more correct to say that using a still, a good operator
      can separate the ethanol that contains ethyl acetate (the heads, etc)
      from the ethanol that doesn't. To me this is not "effective" as the
      heads contain far more ethanol than anything else and I make ethanol
      to drink and not tip down the drain. As I said, stills are great for
      separating alcohol from water, but that doesn't make them the best
      tool for every job. Removing ester-related flavours with a still has
      all the finesse of opening walnuts with a sledgehammer. The secret is
      knowing your enemy:

      Food is acidic. Just about everything we eat has a pH less than 7
      (See http://www.phsciences.com/about_ph/ph_foods.asp). Acid inhibits
      bacteria growth and is the environment in which esters are formed.
      The chemical reaction that produces esters, however, can be reversed –
      when taken out of an acidic environment esters hydrolise back into
      the acid and alcohol from which they were originally formed. This is
      why food acids are so often added to preserved food – it helps
      preserve the flavour as well as preventing spoilage.

      Ethyl acetate is formed during fermentation. After distillation it's
      no longer in and acidic environment and starts to decompose back to
      ethanol and acetic acid. Acetic acid gives vinegar its characteristic
      taste and although pungent, it's far less detectable than ethyl
      acetate – not great, but less bad. As decompostion produces an acid
      it tends to slow the rate of further decomposition, but eventually it
      does happen. If you have the time, people have been getting good
      results from sticking alcohol in barrels and waiting a decade.

      If you don't have the time then don't worry lots of things can be
      used to speed up the process: agitation/aeration, light (called
      photodecomposition) do this. The resulting acetic acid has a boiling
      point of 118 degrees C so it's much easier than ethyl acetate to
      separate from ethanol in a subsequent distillation. If you add some
      mild alkali (sodium bicarbonate, sodium carbonate or calcium
      carbonate) into the mix you can speed up the decomposition time and
      also precipitate out the acetic acid. By adding a couple of teaspoons
      of sodium bicarb to your nastiest smelling heads and aerating them
      with an aquarium pump and air-stone for a week you will end up with
      something that smells OK. Not quite good enough to drink, but more
      than good enough to redistil.

      This is the real way to solve the ethyl acetate problem – not by
      pouring your (mostly ethanol) heads down the drain. You get to
      recover all the ethanol that the ethyl acetate had spoiled and (the
      really elegant part) some of the ethyl acetate is actually turned
      back into ethanol. The point to remember is the same process will
      reduce all ester-related flavours, and not just ethyl acetate,
      including the ones that exist in immeasurable, but still detectable
      quantities. You don't even need to know what esters they are!! They
      all breakdown into different components, which you may not
      particularly want either but will all have less impact on overall
      flavour than the original ester.

      Once I learned this I changed my process to double distil everything.
      After the first distillation I throw in some sodium carbonate and
      aerate for a week before distilling again. I don't separate the heads
      from the second distillation because there's nothing to separate and
      the result doesn't need carbon filtration. More importantly, nothing
      I boil off ever goes down the drain - not a single drop. My end-to-
      end efficiency from sugar to drinkable spirit is 90% with the cost of
      consumables and wastage very low. Plenty depends on your ingredients,
      equipment and process, but you get the basic idea.

      Cheers,
      DP
    • Cary Rhodes
      thanks dp I learned alot. I only vaguely remember esters from organic chemistry. And that was 20 years ago. I printed it out and put it in my reference file.
      Message 2 of 10 , Mar 31, 2005
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        thanks dp

        I learned alot.

        I only vaguely remember esters from organic chemistry. And that was
        20 years ago.

        I printed it out and put it in my reference file.


        cary r




        --- In Distillers@yahoogroups.com, "dropped_pie" <dropped_pie@y...>
        wrote:
        >
        > Carbon and methanol (snore) have had more than their share of
        posts
        > in this newsgroup. Esters, on the other hand, are a subject that
        gets
        > far less attention than it should. I feel there is too much focus
        on
        > ethanol and water, and not the properties of the impurities we are
        > really trying to remove. My still already removes more than enough
        > water - I have to add water back before I use it's output so
        clearly
        > removing water is not my main objective. Everything seems to hinge
        on
        > the assumption that if your still is good at separating alcohol
        and
        > water then it must be good at removing everything else. This
        > assumption is loose at best and ignores the fact that with a
        little
        > encouragement some of the worst impurities will remove themselves.
        >
        > Esters are flavour compounds responsible for many of the
        > characteristic tastes we know very well:
        >
        > Propyl acetate (Pears)
        > Octyl acetate (Oranges)
        > Isoamyl acetate (Banana)
        > Ethyl butyrate (Pineapple)
        > Butyl acetate (Apple)
        > Methyl trans-cinnamate (Strawberry)
        > Ethyl cinnamate(Cinnamon)
        >
        > (See http://www.leffingwell.com/esters.htm. There are many others
        and
        > a web search will turn up many more if you're interested.)
        >
        > Esters are the product of a reaction between an organic acid and
        an
        > alcohol. Read the back of a wine bottle you'll see wine described
        as
        > tasting of all sorts of different fruit (except grapes, of course
        > because any fool can do that). Yeast, by its very nature, produces
        a
        > range of organic acids and a range of alcohols during the
        > fermentation process. These combine to form a range of esters
        > responsible (along with other chemicals) for the flavours in wine
        > that aren't in the original grape juice. This is where the
        interests
        > of a winemaker differ from someone trying to make clean neutral
        > spirits - winemakers see ester formation as desirable. Yeast
        makers
        > even advertise their yeasts on how good they are at producing damn
        > esters.
        >
        > The problem with esters is that a little goes such a long way.
        Most
        > have detection thresholds measured in parts per billion (ppb).
        Ethyl
        > butyrate – the fruity pineapple ester listed above - has an odour
        > detection threshold in water of 1ppb. As a comparison, ethanol in
        air
        > has an odour detection threshold of about 50 parts per million
        (ppm).
        > In other words, it's odour is 50,000 times more powerful than
        > ethanol. For those of you obsessed by percentages, your distillate
        > could be 99.9999999% ethyl butyrate free and you'd still be able
        to
        > smell the damn stuff. Great if that's what you want, bad if you
        don't.
        >
        > The ester of the most relevance to home distilling is ethyl
        acetate.
        > Ethanol oxidises to form acetic acid. Acetic acid and ethanol
        react
        > to form ethyl acetate. It's no real surprise that you are going to
        > end up with some of this stuff in your brew - yeast puts it there.
        > The good news is its odour detection level is a relatively high
        for
        > an ester at 5000 ppb (or 0.0005%); the bad news is it has a nasty
        > solvent-like smell you're probably already familiar with. And
        there's
        > more bad news…
        >
        > By itself, it boils at 77 degrees, which is pretty close to the
        > boiling point of ethanol. It forms azeotropes with both ethanol
        and
        > water, and another when all three of them are mixed together
        > (although all at mixture ratios you are never likely to see). I
        have
        > heard many claims that ethyl acetate can be effectively removed by
        a
        > still. It's more correct to say that using a still, a good
        operator
        > can separate the ethanol that contains ethyl acetate (the heads,
        etc)
        > from the ethanol that doesn't. To me this is not "effective" as
        the
        > heads contain far more ethanol than anything else and I make
        ethanol
        > to drink and not tip down the drain. As I said, stills are great
        for
        > separating alcohol from water, but that doesn't make them the best
        > tool for every job. Removing ester-related flavours with a still
        has
        > all the finesse of opening walnuts with a sledgehammer. The secret
        is
        > knowing your enemy:
        >
        > Food is acidic. Just about everything we eat has a pH less than 7
        > (See http://www.phsciences.com/about_ph/ph_foods.asp). Acid
        inhibits
        > bacteria growth and is the environment in which esters are formed.
        > The chemical reaction that produces esters, however, can be
        reversed –
        > when taken out of an acidic environment esters hydrolise back
        into
        > the acid and alcohol from which they were originally formed. This
        is
        > why food acids are so often added to preserved food – it helps
        > preserve the flavour as well as preventing spoilage.
        >
        > Ethyl acetate is formed during fermentation. After distillation
        it's
        > no longer in and acidic environment and starts to decompose back
        to
        > ethanol and acetic acid. Acetic acid gives vinegar its
        characteristic
        > taste and although pungent, it's far less detectable than ethyl
        > acetate – not great, but less bad. As decompostion produces an
        acid
        > it tends to slow the rate of further decomposition, but eventually
        it
        > does happen. If you have the time, people have been getting good
        > results from sticking alcohol in barrels and waiting a decade.
        >
        > If you don't have the time then don't worry lots of things can be
        > used to speed up the process: agitation/aeration, light (called
        > photodecomposition) do this. The resulting acetic acid has a
        boiling
        > point of 118 degrees C so it's much easier than ethyl acetate to
        > separate from ethanol in a subsequent distillation. If you add
        some
        > mild alkali (sodium bicarbonate, sodium carbonate or calcium
        > carbonate) into the mix you can speed up the decomposition time
        and
        > also precipitate out the acetic acid. By adding a couple of
        teaspoons
        > of sodium bicarb to your nastiest smelling heads and aerating them
        > with an aquarium pump and air-stone for a week you will end up
        with
        > something that smells OK. Not quite good enough to drink, but more
        > than good enough to redistil.
        >
        > This is the real way to solve the ethyl acetate problem – not by
        > pouring your (mostly ethanol) heads down the drain. You get to
        > recover all the ethanol that the ethyl acetate had spoiled and
        (the
        > really elegant part) some of the ethyl acetate is actually turned
        > back into ethanol. The point to remember is the same process will
        > reduce all ester-related flavours, and not just ethyl acetate,
        > including the ones that exist in immeasurable, but still
        detectable
        > quantities. You don't even need to know what esters they are!!
        They
        > all breakdown into different components, which you may not
        > particularly want either but will all have less impact on overall
        > flavour than the original ester.
        >
        > Once I learned this I changed my process to double distil
        everything.
        > After the first distillation I throw in some sodium carbonate and
        > aerate for a week before distilling again. I don't separate the
        heads
        > from the second distillation because there's nothing to separate
        and
        > the result doesn't need carbon filtration. More importantly,
        nothing
        > I boil off ever goes down the drain - not a single drop. My end-to-
        > end efficiency from sugar to drinkable spirit is 90% with the cost
        of
        > consumables and wastage very low. Plenty depends on your
        ingredients,
        > equipment and process, but you get the basic idea.
        >
        > Cheers,
        > DP
      • Rick Strang
        How much volume do you loose on second distil. Example on my only try (1st run) I single distilled for 3lt @ 65% from 20lt which when cut gave me 5.25lt. If I
        Message 3 of 10 , Mar 31, 2005
        • 0 Attachment
          How much volume do you loose on second distil.
          Example on my only try (1st run) I single distilled for 3lt @ 65% from 20lt which when cut gave me 5.25lt.
          If I 2nd distilled I would have to make another smaller still I think.
          Rick.
          ----- Original Message -----
          From: dropped_pie
          To: Distillers@yahoogroups.com
          Sent: Friday, April 01, 2005 10:45 AM
          Subject: [Distillers] Esters



          Carbon and methanol (snore) have had more than their share of posts
          in this newsgroup. Esters, on the other hand, are a subject that gets
          far less attention than it should. I feel there is too much focus on
          ethanol and water, and not the properties of the impurities we are
          really trying to remove. My still already removes more than enough
          water - I have to add water back before I use it's output so clearly
          removing water is not my main objective. Everything seems to hinge on
          the assumption that if your still is good at separating alcohol and
          water then it must be good at removing everything else. This
          assumption is loose at best and ignores the fact that with a little
          encouragement some of the worst impurities will remove themselves.

          Esters are flavour compounds responsible for many of the
          characteristic tastes we know very well:

          Propyl acetate (Pears)
          Octyl acetate (Oranges)
          Isoamyl acetate (Banana)
          Ethyl butyrate (Pineapple)
          Butyl acetate (Apple)
          Methyl trans-cinnamate (Strawberry)
          Ethyl cinnamate(Cinnamon)

          (See http://www.leffingwell.com/esters.htm. There are many others and
          a web search will turn up many more if you're interested.)

          Esters are the product of a reaction between an organic acid and an
          alcohol. Read the back of a wine bottle you'll see wine described as
          tasting of all sorts of different fruit (except grapes, of course
          because any fool can do that). Yeast, by its very nature, produces a
          range of organic acids and a range of alcohols during the
          fermentation process. These combine to form a range of esters
          responsible (along with other chemicals) for the flavours in wine
          that aren't in the original grape juice. This is where the interests
          of a winemaker differ from someone trying to make clean neutral
          spirits - winemakers see ester formation as desirable. Yeast makers
          even advertise their yeasts on how good they are at producing damn
          esters.

          The problem with esters is that a little goes such a long way. Most
          have detection thresholds measured in parts per billion (ppb). Ethyl
          butyrate - the fruity pineapple ester listed above - has an odour
          detection threshold in water of 1ppb. As a comparison, ethanol in air
          has an odour detection threshold of about 50 parts per million (ppm).
          In other words, it's odour is 50,000 times more powerful than
          ethanol. For those of you obsessed by percentages, your distillate
          could be 99.9999999% ethyl butyrate free and you'd still be able to
          smell the damn stuff. Great if that's what you want, bad if you don't.

          The ester of the most relevance to home distilling is ethyl acetate.
          Ethanol oxidises to form acetic acid. Acetic acid and ethanol react
          to form ethyl acetate. It's no real surprise that you are going to
          end up with some of this stuff in your brew - yeast puts it there.
          The good news is its odour detection level is a relatively high for
          an ester at 5000 ppb (or 0.0005%); the bad news is it has a nasty
          solvent-like smell you're probably already familiar with. And there's
          more bad news.

          By itself, it boils at 77 degrees, which is pretty close to the
          boiling point of ethanol. It forms azeotropes with both ethanol and
          water, and another when all three of them are mixed together
          (although all at mixture ratios you are never likely to see). I have
          heard many claims that ethyl acetate can be effectively removed by a
          still. It's more correct to say that using a still, a good operator
          can separate the ethanol that contains ethyl acetate (the heads, etc)
          from the ethanol that doesn't. To me this is not "effective" as the
          heads contain far more ethanol than anything else and I make ethanol
          to drink and not tip down the drain. As I said, stills are great for
          separating alcohol from water, but that doesn't make them the best
          tool for every job. Removing ester-related flavours with a still has
          all the finesse of opening walnuts with a sledgehammer. The secret is
          knowing your enemy:

          Food is acidic. Just about everything we eat has a pH less than 7
          (See http://www.phsciences.com/about_ph/ph_foods.asp). Acid inhibits
          bacteria growth and is the environment in which esters are formed.
          The chemical reaction that produces esters, however, can be reversed -
          when taken out of an acidic environment esters hydrolise back into
          the acid and alcohol from which they were originally formed. This is
          why food acids are so often added to preserved food - it helps
          preserve the flavour as well as preventing spoilage.

          Ethyl acetate is formed during fermentation. After distillation it's
          no longer in and acidic environment and starts to decompose back to
          ethanol and acetic acid. Acetic acid gives vinegar its characteristic
          taste and although pungent, it's far less detectable than ethyl
          acetate - not great, but less bad. As decompostion produces an acid
          it tends to slow the rate of further decomposition, but eventually it
          does happen. If you have the time, people have been getting good
          results from sticking alcohol in barrels and waiting a decade.

          If you don't have the time then don't worry lots of things can be
          used to speed up the process: agitation/aeration, light (called
          photodecomposition) do this. The resulting acetic acid has a boiling
          point of 118 degrees C so it's much easier than ethyl acetate to
          separate from ethanol in a subsequent distillation. If you add some
          mild alkali (sodium bicarbonate, sodium carbonate or calcium
          carbonate) into the mix you can speed up the decomposition time and
          also precipitate out the acetic acid. By adding a couple of teaspoons
          of sodium bicarb to your nastiest smelling heads and aerating them
          with an aquarium pump and air-stone for a week you will end up with
          something that smells OK. Not quite good enough to drink, but more
          than good enough to redistil.

          This is the real way to solve the ethyl acetate problem - not by
          pouring your (mostly ethanol) heads down the drain. You get to
          recover all the ethanol that the ethyl acetate had spoiled and (the
          really elegant part) some of the ethyl acetate is actually turned
          back into ethanol. The point to remember is the same process will
          reduce all ester-related flavours, and not just ethyl acetate,
          including the ones that exist in immeasurable, but still detectable
          quantities. You don't even need to know what esters they are!! They
          all breakdown into different components, which you may not
          particularly want either but will all have less impact on overall
          flavour than the original ester.

          Once I learned this I changed my process to double distil everything.
          After the first distillation I throw in some sodium carbonate and
          aerate for a week before distilling again. I don't separate the heads
          from the second distillation because there's nothing to separate and
          the result doesn't need carbon filtration. More importantly, nothing
          I boil off ever goes down the drain - not a single drop. My end-to-
          end efficiency from sugar to drinkable spirit is 90% with the cost of
          consumables and wastage very low. Plenty depends on your ingredients,
          equipment and process, but you get the basic idea.

          Cheers,
          DP






          Distillers list archives : http://archive.nnytech.net/
          FAQ and other information at http://homedistiller.org



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        • Rana Pipiens
          Rick, don t build another still. Just do a number of batches and combine the low wines from the stripping runs when you have enough for a spirit run. Rana
          Message 4 of 10 , Apr 1, 2005
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            Rick, don't build another still. Just do a number of batches and combine the low wines from the stripping runs when you have enough for a spirit run. Rana

            Rick Strang <rickstrang@...> wrote:How much volume do you loose on second distil.
            Example on my only try (1st run) I single distilled for 3lt @ 65% from 20lt which when cut gave me 5.25lt.
            If I 2nd distilled I would have to make another smaller still I think.
            Rick.







            Distillers list archives : http://archive.nnytech.net/
            FAQ and other information at http://homedistiller.org



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            Distillers-unsubscribe@yahoogroups.com

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            FAQ and other information at http://homedistiller.org



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            To visit your group on the web, go to:
            http://groups.yahoo.com/group/Distillers/

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          • Campbell Ritchie
            ... wrote: Big Snip ... everything. ... =================================================================== After about 2 years of fine tuning my rig and
            Message 5 of 10 , Apr 10, 2005
            • 0 Attachment
              --- In Distillers@yahoogroups.com, "dropped_pie" <dropped_pie@y...>
              wrote:

              Big Snip

              > Once I learned this I changed my process to double distil
              everything.
              > After the first distillation I throw in some sodium carbonate and
              > aerate for a week before distilling again. I don't separate the
              >heads from the second distillation because there's nothing to
              >separate and the result doesn't need carbon filtration.

              ===================================================================

              After about 2 years of fine tuning my rig and procedures I can
              separate main run from tails like flicking a switch, no more than a
              couple of hundred mils lost at changeover but I am still getting a
              large heads phase, probably 25% of run according to my increasingly
              sensitive nose.

              Quick question. How much sodium carbonate to heads do you use and do
              you add it to full strength heads or do you dilute them?

              Thanks for the very informative post.

              Campbell
            • rocky_creek1
              In other places I have noticed that the base is added before the second distillation, to avoud blue crystols in the first. Can you remind me of why the second
              Message 6 of 10 , Apr 10, 2005
              • 0 Attachment
                In other places I have noticed that the base is added before the
                second distillation, to avoud blue crystols in the first. Can you
                remind me of why the second distillation acts differently from the
                first in producing copper sulphate I'm guessing.


                > From: dropped_pie
                > To: Distillers@yahoogroups.com
                > Sent: Friday, April 01, 2005 10:45 AM
                > Subject: [Distillers] Esters
                >
                >
                >
                > Carbon and methanol (snore) have had more than their share of posts
                > in this newsgroup. Esters, on the other hand, are a subject that gets
                > far less attention than it should. I feel there is too much focus on
                > ethanol and water, and not the properties of the impurities we are
                > really trying to remove. My still already removes more than enough
                > water - I have to add water back before I use it's output so clearly
                > removing water is not my main objective. Everything seems to hinge on
                > the assumption that if your still is good at separating alcohol and
                > water then it must be good at removing everything else. This
                > assumption is loose at best and ignores the fact that with a little
                > encouragement some of the worst impurities will remove themselves.
                >
                > Esters are flavour compounds responsible for many of the
                > characteristic tastes we know very well:
                >
                > Propyl acetate (Pears)
                > Octyl acetate (Oranges)
                > Isoamyl acetate (Banana)
                > Ethyl butyrate (Pineapple)
                > Butyl acetate (Apple)
                > Methyl trans-cinnamate (Strawberry)
                > Ethyl cinnamate(Cinnamon)
                >
                > (See http://www.leffingwell.com/esters.htm. There are many others and
                > a web search will turn up many more if you're interested.)
                >
                > Esters are the product of a reaction between an organic acid and an
                > alcohol. Read the back of a wine bottle you'll see wine described as
                > tasting of all sorts of different fruit (except grapes, of course
                > because any fool can do that). Yeast, by its very nature, produces a
                > range of organic acids and a range of alcohols during the
                > fermentation process. These combine to form a range of esters
                > responsible (along with other chemicals) for the flavours in wine
                > that aren't in the original grape juice. This is where the interests
                > of a winemaker differ from someone trying to make clean neutral
                > spirits - winemakers see ester formation as desirable. Yeast makers
                > even advertise their yeasts on how good they are at producing damn
                > esters.
                >
                > The problem with esters is that a little goes such a long way. Most
                > have detection thresholds measured in parts per billion (ppb). Ethyl
                > butyrate - the fruity pineapple ester listed above - has an odour
                > detection threshold in water of 1ppb. As a comparison, ethanol in air
                > has an odour detection threshold of about 50 parts per million (ppm).
                > In other words, it's odour is 50,000 times more powerful than
                > ethanol. For those of you obsessed by percentages, your distillate
                > could be 99.9999999% ethyl butyrate free and you'd still be able to
                > smell the damn stuff. Great if that's what you want, bad if you don't.
                >
                > The ester of the most relevance to home distilling is ethyl acetate.
                > Ethanol oxidises to form acetic acid. Acetic acid and ethanol react
                > to form ethyl acetate. It's no real surprise that you are going to
                > end up with some of this stuff in your brew - yeast puts it there.
                > The good news is its odour detection level is a relatively high for
                > an ester at 5000 ppb (or 0.0005%); the bad news is it has a nasty
                > solvent-like smell you're probably already familiar with. And there's
                > more bad news.
                >
                > By itself, it boils at 77 degrees, which is pretty close to the
                > boiling point of ethanol. It forms azeotropes with both ethanol and
                > water, and another when all three of them are mixed together
                > (although all at mixture ratios you are never likely to see). I have
                > heard many claims that ethyl acetate can be effectively removed by a
                > still. It's more correct to say that using a still, a good operator
                > can separate the ethanol that contains ethyl acetate (the heads, etc)
                > from the ethanol that doesn't. To me this is not "effective" as the
                > heads contain far more ethanol than anything else and I make ethanol
                > to drink and not tip down the drain. As I said, stills are great for
                > separating alcohol from water, but that doesn't make them the best
                > tool for every job. Removing ester-related flavours with a still has
                > all the finesse of opening walnuts with a sledgehammer. The secret is
                > knowing your enemy:
                >
                > Food is acidic. Just about everything we eat has a pH less than 7
                > (See http://www.phsciences.com/about_ph/ph_foods.asp). Acid inhibits
                > bacteria growth and is the environment in which esters are formed.
                > The chemical reaction that produces esters, however, can be reversed -
                > when taken out of an acidic environment esters hydrolise back into
                > the acid and alcohol from which they were originally formed. This is
                > why food acids are so often added to preserved food - it helps
                > preserve the flavour as well as preventing spoilage.
                >
                > Ethyl acetate is formed during fermentation. After distillation it's
                > no longer in and acidic environment and starts to decompose back to
                > ethanol and acetic acid. Acetic acid gives vinegar its characteristic
                > taste and although pungent, it's far less detectable than ethyl
                > acetate - not great, but less bad. As decompostion produces an acid
                > it tends to slow the rate of further decomposition, but eventually it
                > does happen. If you have the time, people have been getting good
                > results from sticking alcohol in barrels and waiting a decade.
                >
                > If you don't have the time then don't worry lots of things can be
                > used to speed up the process: agitation/aeration, light (called
                > photodecomposition) do this. The resulting acetic acid has a boiling
                > point of 118 degrees C so it's much easier than ethyl acetate to
                > separate from ethanol in a subsequent distillation. If you add some
                > mild alkali (sodium bicarbonate, sodium carbonate or calcium
                > carbonate) into the mix you can speed up the decomposition time and
                > also precipitate out the acetic acid. By adding a couple of teaspoons
                > of sodium bicarb to your nastiest smelling heads and aerating them
                > with an aquarium pump and air-stone for a week you will end up with
                > something that smells OK. Not quite good enough to drink, but more
                > than good enough to redistil.
                >
                > This is the real way to solve the ethyl acetate problem - not by
                > pouring your (mostly ethanol) heads down the drain. You get to
                > recover all the ethanol that the ethyl acetate had spoiled and (the
                > really elegant part) some of the ethyl acetate is actually turned
                > back into ethanol. The point to remember is the same process will
                > reduce all ester-related flavours, and not just ethyl acetate,
                > including the ones that exist in immeasurable, but still detectable
                > quantities. You don't even need to know what esters they are!! They
                > all breakdown into different components, which you may not
                > particularly want either but will all have less impact on overall
                > flavour than the original ester.
                >
                > Once I learned this I changed my process to double distil everything.
                > After the first distillation I throw in some sodium carbonate and
                > aerate for a week before distilling again. I don't separate the heads
                > from the second distillation because there's nothing to separate and
                > the result doesn't need carbon filtration. More importantly, nothing
                > I boil off ever goes down the drain - not a single drop. My end-to-
                > end efficiency from sugar to drinkable spirit is 90% with the cost of
                > consumables and wastage very low. Plenty depends on your ingredients,
                > equipment and process, but you get the basic idea.
                >
                > Cheers,
                > DP
                >
                >
                >
                >
                >
                >
                > Distillers list archives : http://archive.nnytech.net/
                > FAQ and other information at http://homedistiller.org
                >
                >
                >
                >
                ------------------------------------------------------------------------------
                > Yahoo! Groups Links
                >
                > a.. To visit your group on the web, go to:
                > http://groups.yahoo.com/group/Distillers/
                >
                > b.. To unsubscribe from this group, send an email to:
                > Distillers-unsubscribe@yahoogroups.com
                >
                > c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of
                Service.
                >
                >
                >
                > [Non-text portions of this message have been removed]
              • rocky_creek1
                Excessive ammonia from nutrients in the first distillation react in a basic enviorment to produce the crystals.
                Message 7 of 10 , Apr 10, 2005
                • 0 Attachment
                  Excessive ammonia from nutrients in the first distillation react in a
                  basic enviorment to produce the crystals.


                  --- In Distillers@yahoogroups.com, "dropped_pie" <dropped_pie@y...> wrote:
                  >
                  > Carbon and methanol (snore) have had more than their share of posts
                  > in this newsgroup. Esters, on the other hand, are a subject that gets
                  > far less attention than it should. I feel there is too much focus on
                  > ethanol and water, and not the properties of the impurities we are
                  > really trying to remove. My still already removes more than enough
                  > water - I have to add water back before I use it's output so clearly
                  > removing water is not my main objective. Everything seems to hinge on
                  > the assumption that if your still is good at separating alcohol and
                  > water then it must be good at removing everything else. This
                  > assumption is loose at best and ignores the fact that with a little
                  > encouragement some of the worst impurities will remove themselves.
                  >
                  > Esters are flavour compounds responsible for many of the
                  > characteristic tastes we know very well:
                  >
                  > Propyl acetate (Pears)
                  > Octyl acetate (Oranges)
                  > Isoamyl acetate (Banana)
                  > Ethyl butyrate (Pineapple)
                  > Butyl acetate (Apple)
                  > Methyl trans-cinnamate (Strawberry)
                  > Ethyl cinnamate(Cinnamon)
                  >
                  > (See http://www.leffingwell.com/esters.htm. There are many others and
                  > a web search will turn up many more if you're interested.)
                  >
                  > Esters are the product of a reaction between an organic acid and an
                  > alcohol. Read the back of a wine bottle you'll see wine described as
                  > tasting of all sorts of different fruit (except grapes, of course
                  > because any fool can do that). Yeast, by its very nature, produces a
                  > range of organic acids and a range of alcohols during the
                  > fermentation process. These combine to form a range of esters
                  > responsible (along with other chemicals) for the flavours in wine
                  > that aren't in the original grape juice. This is where the interests
                  > of a winemaker differ from someone trying to make clean neutral
                  > spirits - winemakers see ester formation as desirable. Yeast makers
                  > even advertise their yeasts on how good they are at producing damn
                  > esters.
                  >
                  > The problem with esters is that a little goes such a long way. Most
                  > have detection thresholds measured in parts per billion (ppb). Ethyl
                  > butyrate – the fruity pineapple ester listed above - has an odour
                  > detection threshold in water of 1ppb. As a comparison, ethanol in air
                  > has an odour detection threshold of about 50 parts per million (ppm).
                  > In other words, it's odour is 50,000 times more powerful than
                  > ethanol. For those of you obsessed by percentages, your distillate
                  > could be 99.9999999% ethyl butyrate free and you'd still be able to
                  > smell the damn stuff. Great if that's what you want, bad if you don't.
                  >
                  > The ester of the most relevance to home distilling is ethyl acetate.
                  > Ethanol oxidises to form acetic acid. Acetic acid and ethanol react
                  > to form ethyl acetate. It's no real surprise that you are going to
                  > end up with some of this stuff in your brew - yeast puts it there.
                  > The good news is its odour detection level is a relatively high for
                  > an ester at 5000 ppb (or 0.0005%); the bad news is it has a nasty
                  > solvent-like smell you're probably already familiar with. And there's
                  > more bad news…
                  >
                  > By itself, it boils at 77 degrees, which is pretty close to the
                  > boiling point of ethanol. It forms azeotropes with both ethanol and
                  > water, and another when all three of them are mixed together
                  > (although all at mixture ratios you are never likely to see). I have
                  > heard many claims that ethyl acetate can be effectively removed by a
                  > still. It's more correct to say that using a still, a good operator
                  > can separate the ethanol that contains ethyl acetate (the heads, etc)
                  > from the ethanol that doesn't. To me this is not "effective" as the
                  > heads contain far more ethanol than anything else and I make ethanol
                  > to drink and not tip down the drain. As I said, stills are great for
                  > separating alcohol from water, but that doesn't make them the best
                  > tool for every job. Removing ester-related flavours with a still has
                  > all the finesse of opening walnuts with a sledgehammer. The secret is
                  > knowing your enemy:
                  >
                  > Food is acidic. Just about everything we eat has a pH less than 7
                  > (See http://www.phsciences.com/about_ph/ph_foods.asp). Acid inhibits
                  > bacteria growth and is the environment in which esters are formed.
                  > The chemical reaction that produces esters, however, can be reversed –
                  > when taken out of an acidic environment esters hydrolise back into
                  > the acid and alcohol from which they were originally formed. This is
                  > why food acids are so often added to preserved food – it helps
                  > preserve the flavour as well as preventing spoilage.
                  >
                  > Ethyl acetate is formed during fermentation. After distillation it's
                  > no longer in and acidic environment and starts to decompose back to
                  > ethanol and acetic acid. Acetic acid gives vinegar its characteristic
                  > taste and although pungent, it's far less detectable than ethyl
                  > acetate – not great, but less bad. As decompostion produces an acid
                  > it tends to slow the rate of further decomposition, but eventually it
                  > does happen. If you have the time, people have been getting good
                  > results from sticking alcohol in barrels and waiting a decade.
                  >
                  > If you don't have the time then don't worry lots of things can be
                  > used to speed up the process: agitation/aeration, light (called
                  > photodecomposition) do this. The resulting acetic acid has a boiling
                  > point of 118 degrees C so it's much easier than ethyl acetate to
                  > separate from ethanol in a subsequent distillation. If you add some
                  > mild alkali (sodium bicarbonate, sodium carbonate or calcium
                  > carbonate) into the mix you can speed up the decomposition time and
                  > also precipitate out the acetic acid. By adding a couple of teaspoons
                  > of sodium bicarb to your nastiest smelling heads and aerating them
                  > with an aquarium pump and air-stone for a week you will end up with
                  > something that smells OK. Not quite good enough to drink, but more
                  > than good enough to redistil.
                  >
                  > This is the real way to solve the ethyl acetate problem – not by
                  > pouring your (mostly ethanol) heads down the drain. You get to
                  > recover all the ethanol that the ethyl acetate had spoiled and (the
                  > really elegant part) some of the ethyl acetate is actually turned
                  > back into ethanol. The point to remember is the same process will
                  > reduce all ester-related flavours, and not just ethyl acetate,
                  > including the ones that exist in immeasurable, but still detectable
                  > quantities. You don't even need to know what esters they are!! They
                  > all breakdown into different components, which you may not
                  > particularly want either but will all have less impact on overall
                  > flavour than the original ester.
                  >
                  > Once I learned this I changed my process to double distil everything.
                  > After the first distillation I throw in some sodium carbonate and
                  > aerate for a week before distilling again. I don't separate the heads
                  > from the second distillation because there's nothing to separate and
                  > the result doesn't need carbon filtration. More importantly, nothing
                  > I boil off ever goes down the drain - not a single drop. My end-to-
                  > end efficiency from sugar to drinkable spirit is 90% with the cost of
                  > consumables and wastage very low. Plenty depends on your ingredients,
                  > equipment and process, but you get the basic idea.
                  >
                  > Cheers,
                  > DP
                • Mark
                  I ve had mixed luck using baking soda. But now that I think about it, I think it did work when baking soda was added a couple of weeks prior to distillation.
                  Message 8 of 10 , Apr 10, 2005
                  • 0 Attachment
                    I've had mixed luck using baking soda. But now that I think about
                    it, I think it did work when baking soda was added a couple of weeks
                    prior to distillation. I guess adding it the night before doesn't
                    provide sufficient time to work.

                    Same question - how much baking soda per litre of 94ish?

                    Mark



                    --- In Distillers@yahoogroups.com, "Campbell Ritchie"
                    <ritchiec@t...> wrote:
                    >
                    > --- In Distillers@yahoogroups.com, "dropped_pie"
                    <dropped_pie@y...>
                    > wrote:
                    >
                    > Big Snip
                    >
                    > > Once I learned this I changed my process to double distil
                    > everything.
                    > > After the first distillation I throw in some sodium carbonate
                    and
                    > > aerate for a week before distilling again. I don't separate the
                    > >heads from the second distillation because there's nothing to
                    > >separate and the result doesn't need carbon filtration.
                    >
                    > ===================================================================
                    >
                    > After about 2 years of fine tuning my rig and procedures I can
                    > separate main run from tails like flicking a switch, no more than
                    a
                    > couple of hundred mils lost at changeover but I am still getting a
                    > large heads phase, probably 25% of run according to my
                    increasingly
                    > sensitive nose.
                    >
                    > Quick question. How much sodium carbonate to heads do you use and
                    do
                    > you add it to full strength heads or do you dilute them?
                    >
                    > Thanks for the very informative post.
                    >
                    > Campbell
                  • Mark
                    I searched my notes and found some events that puzzle me. My yield of drinkable product was higher when I added baking soda, started the boiler and and it
                    Message 9 of 10 , Apr 10, 2005
                    • 0 Attachment
                      I searched my notes and found some events that puzzle me. My yield
                      of "drinkable" product was higher when I added baking soda, started
                      the boiler and and it came up to temperature - but then I had to
                      pull the plug for some reason. A day or days later I'd restart the
                      boiler.

                      Does a heat cycle like this on baking soda hootch enhance the
                      reduction of Esters?

                      Mark


                      --- In Distillers@yahoogroups.com, "Mark" <markgofast@h...> wrote:
                      >
                      > I've had mixed luck using baking soda. But now that I think about
                      > it, I think it did work when baking soda was added a couple of
                      weeks
                      > prior to distillation. I guess adding it the night before doesn't
                      > provide sufficient time to work.
                      >
                      > Same question - how much baking soda per litre of 94ish?
                      >
                      > Mark
                      >
                      >
                      >
                      > --- In Distillers@yahoogroups.com, "Campbell Ritchie"
                      > <ritchiec@t...> wrote:
                      > >
                      > > --- In Distillers@yahoogroups.com, "dropped_pie"
                      > <dropped_pie@y...>
                      > > wrote:
                      > >
                      > > Big Snip
                      > >
                      > > > Once I learned this I changed my process to double distil
                      > > everything.
                      > > > After the first distillation I throw in some sodium carbonate
                      > and
                      > > > aerate for a week before distilling again. I don't separate
                      the
                      > > >heads from the second distillation because there's nothing to
                      > > >separate and the result doesn't need carbon filtration.
                      > >
                      > >
                      ===================================================================
                      > >
                      > > After about 2 years of fine tuning my rig and procedures I can
                      > > separate main run from tails like flicking a switch, no more
                      than
                      > a
                      > > couple of hundred mils lost at changeover but I am still getting
                      a
                      > > large heads phase, probably 25% of run according to my
                      > increasingly
                      > > sensitive nose.
                      > >
                      > > Quick question. How much sodium carbonate to heads do you use
                      and
                      > do
                      > > you add it to full strength heads or do you dilute them?
                      > >
                      > > Thanks for the very informative post.
                      > >
                      > > Campbell
                    • rocky_creek1
                      Do tou, or can you make whisky using this method, or will the result be a more neutral alcohol?
                      Message 10 of 10 , Apr 13, 2005
                      • 0 Attachment
                        Do tou, or can you make whisky using this method, or will the result
                        be a more neutral alcohol?


                        --- In Distillers@yahoogroups.com, "dropped_pie" <dropped_pie@y...> wrote:
                        >
                        > Carbon and methanol (snore) have had more than their share of posts
                        > in this newsgroup. Esters, on the other hand, are a subject that gets
                        > far less attention than it should. I feel there is too much focus on
                        > ethanol and water, and not the properties of the impurities we are
                        > really trying to remove. My still already removes more than enough
                        > water - I have to add water back before I use it's output so clearly
                        > removing water is not my main objective. Everything seems to hinge on
                        > the assumption that if your still is good at separating alcohol and
                        > water then it must be good at removing everything else. This
                        > assumption is loose at best and ignores the fact that with a little
                        > encouragement some of the worst impurities will remove themselves.
                        >
                        > Esters are flavour compounds responsible for many of the
                        > characteristic tastes we know very well:
                        >
                        > Propyl acetate (Pears)
                        > Octyl acetate (Oranges)
                        > Isoamyl acetate (Banana)
                        > Ethyl butyrate (Pineapple)
                        > Butyl acetate (Apple)
                        > Methyl trans-cinnamate (Strawberry)
                        > Ethyl cinnamate(Cinnamon)
                        >
                        > (See http://www.leffingwell.com/esters.htm. There are many others and
                        > a web search will turn up many more if you're interested.)
                        >
                        > Esters are the product of a reaction between an organic acid and an
                        > alcohol. Read the back of a wine bottle you'll see wine described as
                        > tasting of all sorts of different fruit (except grapes, of course
                        > because any fool can do that). Yeast, by its very nature, produces a
                        > range of organic acids and a range of alcohols during the
                        > fermentation process. These combine to form a range of esters
                        > responsible (along with other chemicals) for the flavours in wine
                        > that aren't in the original grape juice. This is where the interests
                        > of a winemaker differ from someone trying to make clean neutral
                        > spirits - winemakers see ester formation as desirable. Yeast makers
                        > even advertise their yeasts on how good they are at producing damn
                        > esters.
                        >
                        > The problem with esters is that a little goes such a long way. Most
                        > have detection thresholds measured in parts per billion (ppb). Ethyl
                        > butyrate – the fruity pineapple ester listed above - has an odour
                        > detection threshold in water of 1ppb. As a comparison, ethanol in air
                        > has an odour detection threshold of about 50 parts per million (ppm).
                        > In other words, it's odour is 50,000 times more powerful than
                        > ethanol. For those of you obsessed by percentages, your distillate
                        > could be 99.9999999% ethyl butyrate free and you'd still be able to
                        > smell the damn stuff. Great if that's what you want, bad if you don't.
                        >
                        > The ester of the most relevance to home distilling is ethyl acetate.
                        > Ethanol oxidises to form acetic acid. Acetic acid and ethanol react
                        > to form ethyl acetate. It's no real surprise that you are going to
                        > end up with some of this stuff in your brew - yeast puts it there.
                        > The good news is its odour detection level is a relatively high for
                        > an ester at 5000 ppb (or 0.0005%); the bad news is it has a nasty
                        > solvent-like smell you're probably already familiar with. And there's
                        > more bad news…
                        >
                        > By itself, it boils at 77 degrees, which is pretty close to the
                        > boiling point of ethanol. It forms azeotropes with both ethanol and
                        > water, and another when all three of them are mixed together
                        > (although all at mixture ratios you are never likely to see). I have
                        > heard many claims that ethyl acetate can be effectively removed by a
                        > still. It's more correct to say that using a still, a good operator
                        > can separate the ethanol that contains ethyl acetate (the heads, etc)
                        > from the ethanol that doesn't. To me this is not "effective" as the
                        > heads contain far more ethanol than anything else and I make ethanol
                        > to drink and not tip down the drain. As I said, stills are great for
                        > separating alcohol from water, but that doesn't make them the best
                        > tool for every job. Removing ester-related flavours with a still has
                        > all the finesse of opening walnuts with a sledgehammer. The secret is
                        > knowing your enemy:
                        >
                        > Food is acidic. Just about everything we eat has a pH less than 7
                        > (See http://www.phsciences.com/about_ph/ph_foods.asp). Acid inhibits
                        > bacteria growth and is the environment in which esters are formed.
                        > The chemical reaction that produces esters, however, can be reversed –
                        > when taken out of an acidic environment esters hydrolise back into
                        > the acid and alcohol from which they were originally formed. This is
                        > why food acids are so often added to preserved food – it helps
                        > preserve the flavour as well as preventing spoilage.
                        >
                        > Ethyl acetate is formed during fermentation. After distillation it's
                        > no longer in and acidic environment and starts to decompose back to
                        > ethanol and acetic acid. Acetic acid gives vinegar its characteristic
                        > taste and although pungent, it's far less detectable than ethyl
                        > acetate – not great, but less bad. As decompostion produces an acid
                        > it tends to slow the rate of further decomposition, but eventually it
                        > does happen. If you have the time, people have been getting good
                        > results from sticking alcohol in barrels and waiting a decade.
                        >
                        > If you don't have the time then don't worry lots of things can be
                        > used to speed up the process: agitation/aeration, light (called
                        > photodecomposition) do this. The resulting acetic acid has a boiling
                        > point of 118 degrees C so it's much easier than ethyl acetate to
                        > separate from ethanol in a subsequent distillation. If you add some
                        > mild alkali (sodium bicarbonate, sodium carbonate or calcium
                        > carbonate) into the mix you can speed up the decomposition time and
                        > also precipitate out the acetic acid. By adding a couple of teaspoons
                        > of sodium bicarb to your nastiest smelling heads and aerating them
                        > with an aquarium pump and air-stone for a week you will end up with
                        > something that smells OK. Not quite good enough to drink, but more
                        > than good enough to redistil.
                        >
                        > This is the real way to solve the ethyl acetate problem – not by
                        > pouring your (mostly ethanol) heads down the drain. You get to
                        > recover all the ethanol that the ethyl acetate had spoiled and (the
                        > really elegant part) some of the ethyl acetate is actually turned
                        > back into ethanol. The point to remember is the same process will
                        > reduce all ester-related flavours, and not just ethyl acetate,
                        > including the ones that exist in immeasurable, but still detectable
                        > quantities. You don't even need to know what esters they are!! They
                        > all breakdown into different components, which you may not
                        > particularly want either but will all have less impact on overall
                        > flavour than the original ester.
                        >
                        > Once I learned this I changed my process to double distil everything.
                        > After the first distillation I throw in some sodium carbonate and
                        > aerate for a week before distilling again. I don't separate the heads
                        > from the second distillation because there's nothing to separate and
                        > the result doesn't need carbon filtration. More importantly, nothing
                        > I boil off ever goes down the drain - not a single drop. My end-to-
                        > end efficiency from sugar to drinkable spirit is 90% with the cost of
                        > consumables and wastage very low. Plenty depends on your ingredients,
                        > equipment and process, but you get the basic idea.
                        >
                        > Cheers,
                        > DP
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