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Theoretical plates in a whisk(e)y still?

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  • Zapata Vive
    Anybody have any idea how how many theoretical plates there are in whisky or whiskey stills? There is some reflux going on in those beautiful pots and lynes,
    Message 1 of 14 , Dec 29, 2008
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      Anybody have any idea how how many theoretical plates there are in whisky or whiskey stills?  There is some reflux going on in those beautiful pots and lynes, but just how much?  Any good guesses out there? 
    • Harry
      ... whisky or whiskey stills? There is some reflux going on in those beautiful pots and lynes, but just how much? Any good guesses out there? ... Column
      Message 2 of 14 , Dec 30, 2008
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        --- In Distillers@yahoogroups.com, "Zapata Vive" <zapatavive@...> wrote:
        >
        > Anybody have any idea how how many theoretical plates there are in
        whisky or whiskey stills? There is some reflux going on in those
        beautiful pots and lynes, but just how much? Any good guesses out
        there?
        >



        Column stills = however many physical plates are put in them (more than
        10)

        Brandy stills (eau-de-vie) = 3 to 5 physical plates



        But you were referring to pot stills, yes?


        Pot still = 1 plate

        Pot still + 1 thumper = 2 plates

        Pot still + 2 thumpers = 3 plates

        Getting the pattern?


        Whiskies are usually charged to the spirit still (2nd still) at 27-30%
        a/v. Then given a single distillation, which yields potable spirit at
        around 70+% a/v.

        Use Tony's site to get a handle on this.
        Try the first calculator at 30% and 1 plate.
        http://homedistiller.org/refluxdesign.htm



        Slainte!
        regards Harry
      • Zapata Vive
        Actually I m wondering about whiskey and whisky stills, not pot stills. Yes, a pot still = 1 plate, pretty much by definition. But a huge copper pot, only
        Message 3 of 14 , Jan 4, 2009
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          Actually I'm wondering about whiskey and whisky stills, not pot stills.  Yes, a pot still = 1 plate, pretty much by definition.  But a huge copper pot, only half full, with an exaggerated tapering top, no insulation, and a lyne arm that sometimes slopes up, does not make a simple pot still.  Maybe the "theoretical plates" are less than 2, but surely more than 1.  If not, why don't they just use flat topped perfectly insulated boilers with just enough headspace to keep the foam under control?
           
          You're a pro though, so I won't pull any quotes that discuss the reflux that occurs in whiskey stills, as I'm sure you've read more than I have on the subject.  But none of the literature that I've read gives any indication for how much reflux occurs in commercial whiskey stills, just that some does, and the amount varies from still to still and distillery to distillery. 
           
          So, any ideas how much reflux is going on in those big whiskey stills?
           
          ----- Original Message -----
          From: Harry
          Sent: Tuesday, December 30, 2008 3:17 AM
          Subject: [Distillers] Re: Theoretical plates in a whisk(e)y still?

          --- In Distillers@yahoogro ups.com, "Zapata Vive" <zapatavive@ ...> wrote:
          >
          > Anybody have any idea how how many theoretical plates there are in
          whisky or whiskey stills? There is some reflux going on in those
          beautiful pots and lynes, but just how much? Any good guesses out
          there?
          >

          Column stills = however many physical plates are put in them (more than
          10)

          Brandy stills (eau-de-vie) = 3 to 5 physical plates

          But you were referring to pot stills, yes?

          Pot still = 1 plate

          Pot still + 1 thumper = 2 plates

          Pot still + 2 thumpers = 3 plates

          Getting the pattern?

          Whiskies are usually charged to the spirit still (2nd still) at 27-30%
          a/v. Then given a single distillation, which yields potable spirit at
          around 70+% a/v.

          Use Tony's site to get a handle on this.
          Try the first calculator at 30% and 1 plate.
          http://homedistille r.org/refluxdesi gn.htm

          Slainte!
          regards Harry

        • Harry
          ... none of the literature that I ve read gives any indication for how much reflux occurs in commercial whiskey stills, just that some does, and the
          Message 4 of 14 , Jan 4, 2009
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            --- In Distillers@yahoogroups.com, "Zapata Vive" <zapatavive@...> wrote:
            >
            <snip>

            none of the literature that I've read gives any indication for how much
            reflux occurs in commercial whiskey stills, just that some does, and
            the amount varies from still to still and distillery to distillery.
            >
            > So, any ideas how much reflux is going on in those big whiskey stills?



            There are no 'theoretical plates' in a plate column. They are actual
            physical plates or trays. Whiskey columns are too big to use packing
            instead of plates.

            Are you referring to whiskey plate columns or whiskey pot stills? To
            my knowledge there's only one (1) whiskey produced commercially that is
            pot distilled and that's Woodford Reserve Bourbon.

            All the rest use plate column designs. As such, the reflux ratio must
            be a certain minimum to maintain steady balanced column action. This
            minimum is somewhere in the region of 2:1 or 3:1 reflux:product ratio.
            Less is bad, more is bad.

            If a particular plate runs low on liquid due to too little reflux
            return, the column is in danger of "dumping". This will require a
            restart and once again bringing the column to equilibrium.

            If there's too much reflux liquid returned, then pressure buildup,
            surging and temperature fluctuation between plates drastically reduces
            efficiency, and the product quality is poor.

            IOW, for plate columns it's all a balancing act.

            Hope that is useful.


            Slainte!
            regards Harry
          • zapatavive@suddenlink.net
            Very useful. I didn t know that the vast majority of whiskey was made in columns. Honestly though I was thinking of scotch whisky stills in particular, and
            Message 5 of 14 , Jan 4, 2009
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              Very useful. I didn't know that the vast majority of whiskey was made in columns. Honestly though I was thinking of scotch whisky stills in particular, and assumed bourbon et al was made in similar stills.

              So I guess I have 2 questions, if I'm not mistaken, the Scots do use pot style stills, right? And if so, could we guess how much reflux happens in the large tops on those stills?

              For example, there are no physical plates in this still, are there?
              http://www.scotchwhisky.net/images/dist/glendronach_still.jpg
              If not, surely a lot of reflux happens in there, right?

              Or these:
              http://www.lochlomonddistillery.com/assets/Images/malt1.jpg
              http://www.popsci.com/files/imagecache/article_image_large/files/articles/Ardmore%20Distillery%20-%20Stills.jpg

              Thanks Harry!
              ---- Harry <gnikomson2000@...> wrote:
              > --- In Distillers@yahoogroups.com, "Zapata Vive" <zapatavive@...> wrote:
              > >
              > <snip>
              >
              > none of the literature that I've read gives any indication for how much
              > reflux occurs in commercial whiskey stills, just that some does, and
              > the amount varies from still to still and distillery to distillery.
              > >
              > > So, any ideas how much reflux is going on in those big whiskey stills?
              >
              >
              >
              > There are no 'theoretical plates' in a plate column. They are actual
              > physical plates or trays. Whiskey columns are too big to use packing
              > instead of plates.
              >
              > Are you referring to whiskey plate columns or whiskey pot stills? To
              > my knowledge there's only one (1) whiskey produced commercially that is
              > pot distilled and that's Woodford Reserve Bourbon.
              >
              > All the rest use plate column designs. As such, the reflux ratio must
              > be a certain minimum to maintain steady balanced column action. This
              > minimum is somewhere in the region of 2:1 or 3:1 reflux:product ratio.
              > Less is bad, more is bad.
              >
              > If a particular plate runs low on liquid due to too little reflux
              > return, the column is in danger of "dumping". This will require a
              > restart and once again bringing the column to equilibrium.
              >
              > If there's too much reflux liquid returned, then pressure buildup,
              > surging and temperature fluctuation between plates drastically reduces
              > efficiency, and the product quality is poor.
              >
              > IOW, for plate columns it's all a balancing act.
              >
              > Hope that is useful.
              >
              >
              > Slainte!
              > regards Harry
              >
            • zapatavive@suddenlink.net
              Very useful. I didn t know that the vast majority of whiskey was made in columns. Honestly though I was thinking of scotch whisky stills in particular, and
              Message 6 of 14 , Jan 4, 2009
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                Very useful. I didn't know that the vast majority of whiskey was made in columns. Honestly though I was thinking of scotch whisky stills in particular, and assumed bourbon et al was made in similar stills.

                So I guess I have 2 questions, if I'm not mistaken, the Scots do use pot style stills, right? And if so, could we guess how much reflux happens in the large tops on those stills?

                For example, there are no physical plates in this still, are there?
                http://www.scotchwhisky.net/images/dist/glendronach_still.jpg
                If not, surely a lot of reflux happens in there, right?

                Or these:
                http://www.lochlomonddistillery.com/assets/Images/malt1.jpg
                http://www.popsci.com/files/imagecache/article_image_large/files/articles/Ardmore%20Distillery%20-%20Stills.jpg

                Thanks Harry!
                ---- Harry <gnikomson2000@...> wrote:
                > --- In Distillers@yahoogroups.com, "Zapata Vive" <zapatavive@...> wrote:
                > >
                > <snip>
                >
                > none of the literature that I've read gives any indication for how much
                > reflux occurs in commercial whiskey stills, just that some does, and
                > the amount varies from still to still and distillery to distillery.
                > >
                > > So, any ideas how much reflux is going on in those big whiskey stills?
                >
                >
                >
                > There are no 'theoretical plates' in a plate column. They are actual
                > physical plates or trays. Whiskey columns are too big to use packing
                > instead of plates.
                >
                > Are you referring to whiskey plate columns or whiskey pot stills? To
                > my knowledge there's only one (1) whiskey produced commercially that is
                > pot distilled and that's Woodford Reserve Bourbon.
                >
                > All the rest use plate column designs. As such, the reflux ratio must
                > be a certain minimum to maintain steady balanced column action. This
                > minimum is somewhere in the region of 2:1 or 3:1 reflux:product ratio.
                > Less is bad, more is bad.
                >
                > If a particular plate runs low on liquid due to too little reflux
                > return, the column is in danger of "dumping". This will require a
                > restart and once again bringing the column to equilibrium.
                >
                > If there's too much reflux liquid returned, then pressure buildup,
                > surging and temperature fluctuation between plates drastically reduces
                > efficiency, and the product quality is poor.
                >
                > IOW, for plate columns it's all a balancing act.
                >
                > Hope that is useful.
                >
                >
                > Slainte!
                > regards Harry
                >
              • Harry
                ... in columns. Honestly though I was thinking of scotch whisky stills in particular, and assumed bourbon et al was made in similar stills. ... pot style
                Message 7 of 14 , Jan 4, 2009
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                  --- In Distillers@yahoogroups.com, <zapatavive@...> wrote:

                  >
                  > Very useful.  I didn't know that the vast majority of whiskey was made in columns.  Honestly though I was thinking of scotch whisky stills in particular, and assumed bourbon et al was made in similar stills.
                  >
                  > So I guess I have 2 questions, if I'm not mistaken, the Scots do use pot style stills, right?  And if so, could we guess how much reflux happens in the large tops on those stills?
                  >
                  > For example, there are no physical plates in this still, are there?
                  > http://www.scotchwhisky.net/images/dist/glendronach_still.jpg
                  > If not, surely a lot of reflux happens in there, right?
                  >
                  > Or these:
                  > http://www.lochlomonddistillery.com/assets/Images/malt1.jpg
                  > http://www.popsci.com/files/imagecache/article_image_large/files/articles/Ardmore%20Distillery%20-%20Stills.jpg
                  >
                  > Thanks Harry! 

                   

                  Heh, ya dinna hae ta tell me twice!  :)

                  First let me say this...the Scotch pot stills of today are a far cry technically from their ancestors, even though they appear similar to the eye.  Modern innovations like gas-fired steam heating (replacing 'direct' firing) and electronic monitoring, plus 'shell & tube' condensers replacing the old 'worm' condensers, and GC analysis makes for a far more precise product than ever before.

                  Couple this with the modern taste for 'blended' malts like Ballantyne's (requires 42 different single malts) and you have a myriad of variables to get your head around.

                  But that doesn't answer your question.  So I'll give you an extract from a recent collaborative paper between Bruichladdich Distillery on Islay in Scotland, and University of Tennessee, Knoxville, TN 37996-2200, USA.


                  <extract>

                  Still Construction and Shape:

                   The pressure profile in pot stills has an influence

                  on the vaporization and condensation of the lower vapor pressure components.

                  Reductions in pressure lower the boiling point of all components and increases in

                  pressure enhance the condensation of these same components on the interior walls of the

                  stills. The construction and shape of the stills should have a noticeable effect on the

                  spirits produced. The copper construction enables excellent heat transfer through the still

                  causing the less volatile, i.e. higher boiling, components to condense on the cooler sides

                  of the still and return to the boiling liquid.

                  In the modeling of the stills using HYSYS engineering software, it was found that

                  assuming that the stills were composed of eight equivalent stages and a reflux ratio of one

                  fourth of the vapor phase was appropriate to fit the data [Rogers 2004]. As noted

                  in the

                  temperature profile data the external surface of the copper stills in the vapor phase region

                  is significantly cooler than the boiling liquid and this temperature is not strongly

                  dependent upon the height above the boiling liquid. The vapor condensate that forms on

                  the still surfaces is enhanced in composition of the higher temperature boiling, i.e. less

                  volatile component, compared to the vapor from which it condenses. This results in

                  reflux of the less volatile components thereby enriching the vapor phase that reaches the

                  condensers in a manner similar to that in a tray or packed column in which the

                  rising

                  vapor phase is contacted with falling liquid phase. Therefore the condensate on the

                  interior of the still should have a higher concentration of the lower vapor pressure or

                  higher boiling components. The copper construction of the still enables the removal of

                  sulfur compounds from the distillate by forming copper sulfates that precipitate out and

                  are not carried over into the final spirits.

                  The height and degree of contraction of the stills affect the surface area for

                  contact with and repeated enrichment of the rising vapor. Furthermore, the manner in

                  which the stills contract can also have an influence. The Bruichladdich stills have a

                  smooth transition from the pot to the neck. Stills that have a significant contraction and

                  then expansion above the liquid level can induce a venturi effect in which the vapor is

                  accelerated and then decelerated in its upward motion. If there is a constant mass flow

                  rate through a venturi, the fluid's average velocity is increased due to the reduction in

                  cross sectional area and the associated increase in kinetic energy causes a reduction in

                  pressure, i.e. pressure volume energy is converted to kinetic energy in the contraction and

                  then the pressure is recovered as the cross section increases. The decrease in pressure

                  begins prior to the rapid contraction and if the boiling liquid level is near the significant

                  contraction, the pressure is lowered and the boiling point of the components lowered.

                  This in turn causes the lower vapor pressure components to be included in the vapor at a

                  lower temperature but as the cross sectional area expands these components will be more

                  prone to condensation on the interior surface of the still and a higher effective reflux

                  ratio. As the liquid level recedes during a run the effect on the boiling is also decreased

                  even though the pressure changes in the venturi section are not. Stills for which a bulge

                  occurs above the boiling liquid have an opposite effect to the venturi: increased pressure

                  preceding the bulge and decreased in the bulge. The pressure profile will also be

                  influenced by the general contraction effect in the onion shaped stills and this in turn will

                  affect the condensation and reflux on the interior surface of the still.

                  </extract>

                   

                   

                  Now, when they say "reflux ratio of one fourth of the vapor phase", bear in mind that the vapour phase has 45 times the volume of the equivalent liquid phase.  This may be useful for those trying to guesstimate, measure or equate detuned LM /VM style rigs as whisky stills.

                  So, there you have it.

                  Slainte!
                  regards Harry

                • abbababbaccc
                  Aha, the great Harry has given incomplete answer so here s my change to nitpick :) Some Irish whiskeys are also made in potstills, both double and triple
                  Message 8 of 14 , Jan 4, 2009
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                    Aha, the great Harry has given incomplete answer so here's my change
                    to nitpick :) Some Irish whiskeys are also made in potstills, both
                    double and triple distilled.

                    Cheers, Riku

                    --- In Distillers@yahoogroups.com, "Harry" <gnikomson2000@...> wrote:
                    >
                    >
                    >
                    > There are no 'theoretical plates' in a plate column. They are
                    actual
                    > physical plates or trays. Whiskey columns are too big to use
                    packing
                    > instead of plates.
                    >
                    > Are you referring to whiskey plate columns or whiskey pot stills?
                    To
                    > my knowledge there's only one (1) whiskey produced commercially
                    that is
                    > pot distilled and that's Woodford Reserve Bourbon.
                    >
                    > All the rest use plate column designs. As such, the reflux ratio
                    must
                    > be a certain minimum to maintain steady balanced column action.
                    This
                    > minimum is somewhere in the region of 2:1 or 3:1 reflux:product
                    ratio.
                    > Less is bad, more is bad.
                    >
                    > If a particular plate runs low on liquid due to too little reflux
                    > return, the column is in danger of "dumping". This will require a
                    > restart and once again bringing the column to equilibrium.
                    >
                    > If there's too much reflux liquid returned, then pressure buildup,
                    > surging and temperature fluctuation between plates drastically
                    reduces
                    > efficiency, and the product quality is poor.
                    >
                    > IOW, for plate columns it's all a balancing act.
                    >
                    > Hope that is useful.
                    >
                    >
                    > Slainte!
                    > regards Harry
                    >
                  • zapatavive@suddenlink.net
                    Now that was exactly what I wanted to read! Thank you once again kind sir!
                    Message 9 of 14 , Jan 5, 2009
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                      Now that was exactly what I wanted to read! Thank you once again kind sir!

                      ---- Harry <gnikomson2000@...> wrote:

                      >
                      > Heh, ya dinna hae ta tell me twice! :)
                      >
                      > First let me say this...the Scotch pot stills of today are a far cry
                      > technically from their ancestors, even though they appear similar to the
                      > eye. Modern innovations like gas-fired steam heating (replacing
                      > 'direct' firing) and electronic monitoring, plus 'shell & tube'
                      > condensers replacing the old 'worm' condensers, and GC analysis makes
                      > for a far more precise product than ever before.
                      >
                      > Couple this with the modern taste for 'blended' malts like Ballantyne's
                      > (requires 42 different single malts) and you have a myriad of variables
                      > to get your head around.
                      >
                      > But that doesn't answer your question. So I'll give you an extract from
                      > a recent collaborative paper between Bruichladdich Distillery on Islay
                      > in Scotland, and University of Tennessee, Knoxville, TN 37996-2200, USA.
                      >
                      >
                      > <extract>
                      >
                      >
                      > Still Construction and Shape:
                    • waljaco
                      Most scottish whisky stills are ex-gin stills from England. Most whisky is blended whisky i.e. pot still (malt whisky) and Coffey (column) still (grain whisky)
                      Message 10 of 14 , Jan 5, 2009
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                        Most scottish whisky stills are ex-gin stills from England. Most whisky is
                        blended whisky i.e. pot still (malt whisky) and Coffey (column) still (grain
                        whisky) products. Most grain whisky goes to english gin manufacturers. Use
                        abv output as your guide for a pot still.
                        wal
                        --- In Distillers@yahoogroups.com, "Zapata Vive" <zapatavive@...> wrote:
                        >
                        > Actually I'm wondering about whiskey and whisky stills, not pot stills. Yes, a
                        pot still = 1 plate, pretty much by definition. But a huge copper pot, only half
                        full, with an exaggerated tapering top, no insulation, and a lyne arm that
                        sometimes slopes up, does not make a simple pot still. Maybe the "theoretical
                        plates" are less than 2, but surely more than 1. If not, why don't they just use
                        flat topped perfectly insulated boilers with just enough headspace to keep the
                        foam under control?
                        >
                        > You're a pro though, so I won't pull any quotes that discuss the reflux that
                        occurs in whiskey stills, as I'm sure you've read more than I have on the
                        subject. But none of the literature that I've read gives any indication for how
                        much reflux occurs in commercial whiskey stills, just that some does, and the
                        amount varies from still to still and distillery to distillery.
                        >
                        > So, any ideas how much reflux is going on in those big whiskey stills?
                        >
                        > ----- Original Message -----
                        > From: Harry
                        > To: Distillers@yahoogroups.com
                        > Sent: Tuesday, December 30, 2008 3:17 AM
                        > Subject: [Distillers] Re: Theoretical plates in a whisk(e)y still?
                        >
                        >
                        > --- In Distillers@yahoogroups.com, "Zapata Vive" <zapatavive@> wrote:
                        > >
                        > > Anybody have any idea how how many theoretical plates there are in
                        > whisky or whiskey stills? There is some reflux going on in those
                        > beautiful pots and lynes, but just how much? Any good guesses out
                        > there?
                        > >
                        >
                        > Column stills = however many physical plates are put in them (more than
                        > 10)
                        >
                        > Brandy stills (eau-de-vie) = 3 to 5 physical plates
                        >
                        > But you were referring to pot stills, yes?
                        >
                        > Pot still = 1 plate
                        >
                        > Pot still + 1 thumper = 2 plates
                        >
                        > Pot still + 2 thumpers = 3 plates
                        >
                        > Getting the pattern?
                        >
                        > Whiskies are usually charged to the spirit still (2nd still) at 27-30%
                        > a/v. Then given a single distillation, which yields potable spirit at
                        > around 70+% a/v.
                        >
                        > Use Tony's site to get a handle on this.
                        > Try the first calculator at 30% and 1 plate.
                        > http://homedistiller.org/refluxdesign.htm
                        >
                        > Slainte!
                        > regards Harry
                        >
                      • Harry
                        ... Are you talking pot stills or columns, Wal? 50% of all Scottish pot stills are built by Forsyth s of Rothe. Pot stills require the boiler to be replaced
                        Message 11 of 14 , Jan 5, 2009
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                          --- In Distillers@yahoogroups.com, "waljaco" <waljaco@...> wrote:
                          >
                          > Most scottish whisky stills are ex-gin stills from England.


                          Are you talking pot stills or columns, Wal?

                          50% of all Scottish pot stills are built by Forsyth's of Rothe. Pot
                          stills require the boiler to be replaced each 25 years, the upper
                          parts each 10-15 years.
                          http://www.thewhiskystore.de/experts/copper.htm

                          For a good description of the birth in 1955 (and subsequent demise in
                          the 1980's) of the experimental Lomond still of Hiram Walker, see
                          here...
                          http://tinyurl.com/7m48ta


                          "There are two main types of Scotch whisky, which in turn can be
                          combined to give further types. Malt whisky can contain no grain
                          other than malted barley, and is almost always distilled in batches
                          in traditional distilleries in pot stills. Grain whisky can be made
                          from unmalted barley or other malted or unmalted grains like wheat
                          and maize. It is usually distilled in industrial-scale continuous
                          column stills called Coffey Stills. There are currently around 100
                          active malt whisky distilleries in Scotland, with several more being
                          planned or built. This compares with just seven grain distilleries in
                          Scotland, though each of these has an output far larger than most
                          malt distilleries."
                          [Source:
                          http://www.undiscoveredscotland.co.uk/usscotfax/ent/whisky.html%5d

                          Slainte!
                          regards Harry
                        • waljaco
                          When gin drinking was suppressed in England the frugal Scots bought up the pot stills - some have/had a limited reflux in the manner of a Moor s Head still.
                          Message 12 of 14 , Jan 7, 2009
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                            When gin drinking was suppressed in England the frugal Scots bought
                            up the pot stills - some have/had a limited reflux in the manner of a
                            Moor's Head still.
                            The frugal Scots also use second-hand barrels to store their product!
                            wal
                            --- In Distillers@yahoogroups.com, "Harry" <gnikomson2000@...> wrote:
                            >
                            > --- In Distillers@yahoogroups.com, "waljaco" <waljaco@> wrote:
                            > >
                            > > Most scottish whisky stills are ex-gin stills from England.
                            >
                            >
                            > Are you talking pot stills or columns, Wal?
                            >
                            > 50% of all Scottish pot stills are built by Forsyth's of Rothe. Pot
                            > stills require the boiler to be replaced each 25 years, the upper
                            > parts each 10-15 years.
                            > http://www.thewhiskystore.de/experts/copper.htm
                            >
                            > For a good description of the birth in 1955 (and subsequent demise in
                            > the 1980's) of the experimental Lomond still of Hiram Walker, see
                            > here...
                            > http://tinyurl.com/7m48ta
                            >
                            >
                            > "There are two main types of Scotch whisky, which in turn can be
                            > combined to give further types. Malt whisky can contain no grain
                            > other than malted barley, and is almost always distilled in batches
                            > in traditional distilleries in pot stills. Grain whisky can be made
                            > from unmalted barley or other malted or unmalted grains like wheat
                            > and maize. It is usually distilled in industrial-scale continuous
                            > column stills called Coffey Stills. There are currently around 100
                            > active malt whisky distilleries in Scotland, with several more being
                            > planned or built. This compares with just seven grain distilleries in
                            > Scotland, though each of these has an output far larger than most
                            > malt distilleries."
                            > [Source:
                            > http://www.undiscoveredscotland.co.uk/usscotfax/ent/whisky.html%5d
                            >
                            > Slainte!
                            > regards Harry
                            >
                          • justin webster
                            hello people, didn t get any bites on the newdistillers list so I m hoping one of you chaps will have some ideas on this: I recently inherited a hand
                            Message 13 of 14 , Jan 8, 2009
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                              hello people,
                              didn't get any bites on the newdistillers list so I'm hoping one of
                              you chaps will have some ideas on this:

                              I recently inherited a hand refractometer which I excitedly put to use
                              on several brews.
                              I was hoping that a combination of SG and Brix would give me a better
                              estimation of alcohol content in the beer.
                              what I have noticed is that my calculations of sugar/alcohol content
                              using the refractometer readings are quite different from those using
                              specific gravity.
                              of course I expected there to be a difference but not to such an extent.

                              here are some numbers from a recent rum batch:
                              calc Brix by volume 25
                              actual Brix start 23
                              actual Brix end 7
                              SG start 1.090
                              SG end .994
                              potential ABV (vol) 14.7
                              potential ABV (Brix) 13.53
                              actual ABV (SG) 12.384
                              actual ABV (Brix) 9.411

                              now I am aware that I have not been fermenting out all sugars
                              (slightly lazy with temperature and Ph management) but I think the SG
                              numbers seem about right.
                              it sure seems like I can never get a brix reading under 7 or 8. this
                              was true with palm sugar washes as well as my recent rum batches.
                              I'm wondering if all the other by-products of fermentation (yeast in
                              particular) would bias the brix reading to a greater extent than the SG.

                              both hydrometer and refractometer seem to be calibrated correctly and
                              I'm pretty sure my math is solid.

                              so can a refractometer be trusted?

                              justin
                            • harisaki2004
                              Justin, I have tried using a refractometer for wine, but is inaccurate because you are dealing with sugar and alcohol based liquid. Stick with hydrometers this
                              Message 14 of 14 , Jan 8, 2009
                              • 0 Attachment
                                Justin,

                                I have tried using a refractometer for wine, but is inaccurate because
                                you are dealing with sugar and alcohol based liquid. Stick with
                                hydrometers this is what the industry uses.

                                Refractometers are OK for mono liquids not binary liquids.

                                regards

                                Hari.


                                --- In Distillers@yahoogroups.com, justin webster <mail@...> wrote:
                                >
                                > hello people,
                                > didn't get any bites on the newdistillers list so I'm hoping one of
                                > you chaps will have some ideas on this:
                                >
                                > I recently inherited a hand refractometer which I excitedly put to use
                                > on several brews.
                                > I was hoping that a combination of SG and Brix would give me a better
                                > estimation of alcohol content in the beer.
                                > what I have noticed is that my calculations of sugar/alcohol content
                                > using the refractometer readings are quite different from those using
                                > specific gravity.
                                > of course I expected there to be a difference but not to such an extent.
                                >
                                > here are some numbers from a recent rum batch:
                                > calc Brix by volume 25
                                > actual Brix start 23
                                > actual Brix end 7
                                > SG start 1.090
                                > SG end .994
                                > potential ABV (vol) 14.7
                                > potential ABV (Brix) 13.53
                                > actual ABV (SG) 12.384
                                > actual ABV (Brix) 9.411
                                >
                                > now I am aware that I have not been fermenting out all sugars
                                > (slightly lazy with temperature and Ph management) but I think the SG
                                > numbers seem about right.
                                > it sure seems like I can never get a brix reading under 7 or 8. this
                                > was true with palm sugar washes as well as my recent rum batches.
                                > I'm wondering if all the other by-products of fermentation (yeast in
                                > particular) would bias the brix reading to a greater extent than the SG.
                                >
                                > both hydrometer and refractometer seem to be calibrated correctly and
                                > I'm pretty sure my math is solid.
                                >
                                > so can a refractometer be trusted?
                                >
                                > justin
                                >
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