Friday Night Fight: 3 Chamber Still vs Double Retort

I'm not going to say anything (yet), I would love to hear your thoughts on the subject. We've spoken about the differences between the two before briefly, so let's focus on comparing the two in this thread.

  1. What do you think the differences are with the product of each one?
  2. Which one do you think has more utility in a production environment?
  3. Which would you rather have regardless of utility/cost?

Comments

  • Hard to say... I'd love to experiment with both to find out.

    The double retort looks to be more versatile, if I were running a pro outfit or starting one today that's what I'd buy. I forget what Larry called it, but the system to feed your high/low/seconds directly from the pot through the condenser back to the retort/trash is a brilliant idea (one I'd like to replicate on a much smaller scale for myself).

    Again hard to say, im kind of obsessed with both. Ryes and rums are my jam, so the 3 colum is what I'd get for my own consumption.

    Planning on building a smaller scale 3 column to satisfy the curiosity, even its its not going to get up to the same pressures/temps as a full size Im hoping it should make some really interesting ryes and rums.

  • @SingleMaltYinzer said: I'm not going to say anything (yet), I would love to hear your thoughts on the subject. We've spoken about the differences between the two before briefly, so let's focus on comparing the two in this thread.

    1. What do you think the differences are with the product of each one?
    2. Which one do you think has more utility in a production environment?
    3. Which would you rather have regardless of utility/cost?

    Not say anything yet?

    StillDragon North America - Your StillDragon® Distributor for North America

  • I am getting the bolted flanges made for mine next month. It will be 750mm diameter and 750mm height. Should be 300l per chamber. I bought the plate copper 18 months ago. I want to do ryes and triticLes and grain itish style whiskeys. Which from what i can tell have never been put through a three chamber still.

  • edited February 2023

    I wouldn't necessarily pick either as a single still in a commercial distillery, though I suppose you could do some kind of double dragon setup on the first kettle, and have both a 4 plate and a double retort pot setup as a custom rig.

    A 3/4 plate is just about the most versatile still there is.

  • Agreed, I remember seeing a cad drawing of one of those SD double headed stills, one side had plates the other the retort system.

  • @Smaug said: Not saying anything yet?

    I wanted to let the sane folks comment before I unleashed my crazy thoughts!

    To me it's the same still but in different configurations. The Double Retort is a "deconstructed" 3 chamber. The Double Retort seems more useful if you had to choose one of the two. If you have a modern example like SD's Caribbean Rum Still with the ability to redirect the vapor path it gives you more utility. If you were to construct the double retort with the retorts the same size as a kettle you essentially have a horizontal 3 chamber still. You could theoretically use the Cousin's process in a 3 Chamber but it would be much more of a pain to do.

    Don't get me wrong though, I would not throw a 3 Chamber still out of bed for eating crackers... I think that's a bad analogy but you get my point.

  • edited February 2023

    I’d argue that a double retort is not at all the same as a 3 chamber, in fact, they are exactly opposite each other if you consider the order of vaporization.

    I’ll wager a bet that the double retort favors low boilers (ester) while the 3 chamber favors high boilers (tails).

  • From a construction point of view (notwithstanding any fabrication limitations), the chamber still is simply easier to execute than three (more or less) stand alone kettles that may or may not be uniformly sized. For a well appointed shop this is just an easier, more basic build.

    Also, considering it's vertical assembly, I reckon a lot more efficient with respect to heat loss.

    And as grim eludes, the process flow is also an easier day of material handling.

    StillDragon North America - Your StillDragon® Distributor for North America

  • I agree 100% with you Larry. It's more purpose built and easier to operate.

    @grim said: they are exactly opposite each other if you consider the order of vaporization. I’ll wager a bet that the double retort favors low boilers (ester) while the 3 chamber favors high boilers (tails).

    That's the key for me though - you can more easily run a Double retort like a 3 Chamber than visa versa. If you were to start the beer/wash in the last retort then more it back to retort 1 then the boil kettle you would effectively be running a 3 Chamber still sans doubler and beer warmer.

    I also think both stills are about creating esters but by different methods. Like you said, the 3 chamber pushes tails into fresh heads/hearts while the Double Retort pushes heads/hearts into hearts/tails.

  • Run a double retort in reverse? Loading beer into the last retort and pumping reverse through? And repeating that over and over?

    You, sir, are a masochist. But, sure, I guess you could.

    Wonder if you could align the geometry in a way that would permit you to gravity flow backwards to the kettle, that would certainly make the workflow far easier, and I believe you could still retain the ability to run distillate back into the retorts in a traditional way (early and late tails respectively).

  • edited February 2023

    @SingleMaltYinzer said: I also think both stills are about creating esters but by different methods. Like you said, the 3 chamber pushes tails into fresh heads/hearts while the Double Retort pushes heads/hearts into hearts/tails.

    Agree, in both cases you are using creative methods to force together two constituent components that would normally not be found together (in the vapor path) at the same exact TIME due to the sequential vaporization that happens in batch distillation.

    Pushing alcohol vapor through acids is a good way to generate a reaction, since the alcohol content is high enough to favor esterification.

    I think what you get that's really interesting in the 3 chamber, is a way to vaporize the very high boiling tails alcohols (fusel alcohols), as opposed to just straight ethanol. Every time these vaporize and condense (think moving upwards), you've got the opportunity to form that ester.

    Ethanol esters are obviously the most common (and maybe least interesting). The fusel alcohols are really where you start to get more interesting.

  • Oldie but goodie.

    It's that fusel set that's really interesting when you think about rum. The ethanol esters tend to be very light, fruity, but very simplistic (one note), it's the heavier fusels that yield you the really complex fruit flavors, especially those more common in higher ester rums.

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  • edited February 2023

    Having synthesized all of these on a bench still, I'll say the propionate esters are most rummy to me, and the lactate esters are most whiskey to me.

    In the case of the 3 chamber or double retort - some of the distillate magic is the reactive chemistry to create these. In straight pot distillation, you don't create these, you simply pass along what might already exist in the wash (through enzymatic esterification that takes place during fermentation), so they exist in the distillate, but not nearly at the same concentrations that can be achieved during these reactive distillations.

    Firmly believe that, especially when you consider the Cousins method attempts to do exactly the same thing, through direct chemistry (and not creatively time traveling).

  • Stew.

    Lipid degradation.

    StillDragon North America - Your StillDragon® Distributor for North America

  • Oh yeah, for sure, not only the lipids in the fermentation feedstock, but also consider distilling on the lees, where you have all the long chain fatty acids that exist in yeast cell membranes.

  • That's why I like really long fermentation times - like 30 days+. It give the yeast time to autolyze. Once they break open you get the "juicy" insides with out having to distill on the lees. It also gives any infection time to grow and add chemical diversity to the mix.

    @grim said: Run a double retort in reverse? Loading beer into the last retort and pumping reverse through? And repeating that over and over?

    You, sir, are a masochist. But, sure, I guess you could.

    Wonder if you could align the geometry in a way that would permit you to gravity flow backwards to the kettle, that would certainly make the workflow far easier, and I believe you could still retain the ability to run distillate back into the retorts in a traditional way (early and late tails respectively).

    Maybe make it so the bottom of the last retort higher than the middle and similarly to the kettle? Vapor up, stillage down.
    Might end up looking like a xylophone. It's also why I think the 3 Chamber is a more efficient/purpose built design. As it has been said before, the workflow is easier.

  • Yeah, that's kind of what I was thinking on the geometry - stepping up with each stage.

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