Loading ...
Sorry, an error occurred while loading the content.

Re: [Distillers] Esters

Expand Messages
  • 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 1 of 10 , Apr 1 7:25 AM
    View Source
    • 0 Attachment
      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



      ------------------------------------------------------------------------------
      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]



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



      ---------------------------------
      Yahoo! Groups Links

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

      To unsubscribe from this group, send an email to:
      Distillers-unsubscribe@yahoogroups.com

      Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.




      ---------------------------------
      Yahoo! Messenger
      Show us what our next emoticon should look like. Join the fun.

      [Non-text portions of this message have been removed]
    • Campbell Ritchie
      ... wrote: Big Snip ... everything. ... =================================================================== After about 2 years of fine tuning my rig and
      Message 2 of 10 , Apr 10 12:41 AM
      View Source
      • 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 3 of 10 , Apr 10 4:16 PM
        View Source
        • 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 4 of 10 , Apr 10 4:22 PM
          View Source
          • 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 5 of 10 , Apr 10 7:55 PM
            View Source
            • 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 6 of 10 , Apr 10 9:03 PM
              View Source
              • 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 7 of 10 , Apr 13 4:12 AM
                View Source
                • 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
                Your message has been successfully submitted and would be delivered to recipients shortly.