cowdery Posted September 4, 2011 Share Posted September 4, 2011 They're not alone and this might well be the next wave. First, the idea that pot stills are inherently superior is a myth, though widely believed.Second, with the exception of Woodford, no one has made bourbon or rye exclusively in pot stills since before Prohibition. It's not the 'normal' way to make American whiskey.Third, most mirco-distillers don't use true pot stills, i.e., alembics (like Woodford does), they use hybrids that have rectification columns. I think they perform more like column stills but because they're charge and not continuous, they technically are pot stills. Fourth, each type is better for different things. If you want to make relatively small batches of lots of different things, the typical hybrid set up that most micros use is probably best. It's very versatile. If you want to produce relatively larger batches of a small number of products -- say a couple of different whiskeys -- and you care about efficiency, a small column still set up is probably best. Column stills are much more efficient than pot stills.All column stills are the same height. The crucial capacity metric is still diameter. The typical column still at one of the major bourbon distilleries will have a diameter of between 48 and 72 inches. I suspect the one PS is installing will be much smaller, maybe 24 inches.I also assume they will have a pot still doubler. It isn't essential, technically, but according to most bourbon-makers, you really can't get the whiskey to taste right without it. Barton is the only major Kentucky distillery that doesn't double everything. I'm not sure when they use it and when they don't. All they say is that they use it when they "need" to.As for your speculation, Tom, there are some issues with especially corn in a pot still, but they can be addressed. Most pot/hybrid stills can have an agitator installed for corn and some other things that otherwise tend to cake and stick. Woodford solves the same problem with a recirculation pump.Referring again to the Wyoming operation, and a similar one being finished up now in far Western Kentucky, these set-ups are designed to produce about 200 gallons of spirit per day, a lot more than a typical micro produces. Link to comment Share on other sites More sharing options...
Tom Troland Posted September 4, 2011 Share Posted September 4, 2011 Thanks for a very informative reply, Chuck! Now I wonder why all column stills are the same height. Is there some principle of physics (e.g. involving vapor pressures) that makes a certain height optimum? Link to comment Share on other sites More sharing options...
cowdery Posted September 4, 2011 Share Posted September 4, 2011 Yes. There has to be about 11 inches of separation between plates to avoid entrainment.Entrainment is bad. Link to comment Share on other sites More sharing options...
Josh Posted September 5, 2011 Share Posted September 5, 2011 That's Entrainment! Link to comment Share on other sites More sharing options...
Tom Troland Posted September 5, 2011 Share Posted September 5, 2011 Speaking of distillation, here is question I have sometimes pondered. Perhaps Cluck or another board member can help. How does a pot still doubler work? The juice is flowing continuously out of the column still. So the pot still doubler must be able to handle this continuous, high volume flow. Yet traditional pot stills work one batch at a time. What's up? Link to comment Share on other sites More sharing options...
tmckenzie Posted September 6, 2011 Share Posted September 6, 2011 Every pot still doubler I have ever seen is what they call a continuos doubler. I still have not figured it out. I think our pot still is the only one of the micro stills that can be used as a true pot still. Meaning we can bypass the column all together. Most have to go through the column. Even with the plates all open and the precondensor shut off it will still run 100 proof or better. Meaning your doubling run will be 160 or better, which is the main reason most craft whiskies taste like wood and nothing else. It ain't the small barrels, it is what is going in them. We intend to install a column still like tps is planning. A few years from now. I do not think pot still are better than column. The pricing is not much different than what people are paying for the pot setups. Link to comment Share on other sites More sharing options...
Gillman Posted September 6, 2011 Share Posted September 6, 2011 Tom, the doubler can handle the flow at its relative size to the column because the volume of the distillate is much reduced by the column distillation stage from the initial stream to the column. The doubler permits a further purification but not too advanced, in order that is to get the distillate under 160 proof and in the range most distillers want for bourbon white dog. If you added another distillation column as some vodka makers do or made the column too tall, the spirit would be too neutral in character for bourbon.The piping between the column and pot still doubler permits this to occur in one operation rather than full condensation with re-charge from the "air" to a second still as in Scotland. It's just more efficient that way and you lose less spirit in the process. The doubling stage boosts the alcohol from about 60% ABV to 80% and this also rids it from some ill-tasting chemical compounds that stay behind with the spent (set back) portion.Gary Link to comment Share on other sites More sharing options...
Tom Troland Posted September 6, 2011 Share Posted September 6, 2011 Many thanks to the authors of the previous two posts for the information! However, I am still unclear about just how the spirit passes through the doubler. Since the alcohol content out of the doubler is higher than that going in, it also must be true that the volume of liquid coming out of the doubler is less than that going in. So what happens to the liquid volume lost in the doubling process? In an ordinary pot still, this excess liquid remains in the bottom of the still. So it can be emptied out once the still is shut down at the end of a batch. But in a continuously operating doubler, there is no shutdown. I imagine, therefore, that there must be a drain pipe that continuously removes the excess liquid from the doubler. Further clarifications are most welcome! Link to comment Share on other sites More sharing options...
doubleblank Posted September 6, 2011 Share Posted September 6, 2011 The damn chemical engineer residing deep inside me has to chime in on entrainment. Entrainment occurs in a distillation column when liquid is carried by the vapor from one tray up to the next one. While the distance from one tray to the next impacts much of the dynamics of distillation, the primary cause of entrainment is high vapor rates in the column. High vapor rates occur from 1) running too much feed into the column and/or 2) the column's diameter is too small for the applicable distillation. IOW, assume you're generating an average of 100 cfm of vapor in a column. As you increase the diameter of the column, the speed at which 100 cfm has to move goes down. If the speed at which the vapor is traveling slows too much, you get the opposite of entrainment.....you get weeping/dumping and the liquid in the column goes crashing to the bottom of the column.Some distillations require the column to be built in sections having different diameters because the vapor rate changes so much from the bottom to the top of the column.As Chuck said, entrainment is bad as it results in the "impurities" you're trying to remove via distillation gets carried upward in the column and into the final product.Randy Link to comment Share on other sites More sharing options...
cowdery Posted September 6, 2011 Share Posted September 6, 2011 The doubler is mis-named because it doesn't double anything. It raises the ABV of the spirit only slightly. There are two kinds, a traditional doubler, in which the vapors coming off the column are fully condensed before being introduced to the doubler; and a thumper, in which the vapors go directly into the doubler and use their energy in the process. So they can operate continuously I'm sure there is some kind of drain to remove excess liquid. The only thing from the doubler that is being kept is what comes off as vapor so that liquid -- which is essentially water -- is discarded. Distillers describe what doubling does as polishing the spirit. It removes a couple of undesirable congeners that the column does not.But just as Randy has a chemical engineer inside him, I most definitely do not, so my ability to explain this stuff technically is limited. Link to comment Share on other sites More sharing options...
Tom Troland Posted September 6, 2011 Share Posted September 6, 2011 Chuck (and others) - Many thanks for further clarifications. I guess the term "pot still doubler" is a total misnomer since, as Chuck says, nothing gets doubled. Plus, the pot still doubler is not really a pot still in the traditional sense of the term (even if it looks like a pot still from the outside). Nonetheless, the term has its uses. It can be used to justify the claim that certain bourbons are "pot still", like A. H. Hirsch (nee Michter's) and Willett Pot Still Reserve. In my line of work (astronomy) we have a similar misnomer - shooting star. It's not a star, and nobody shot it. So we call it a meteor, instead. So we need a new term for pot still doubler. How about "pot polisher"? Link to comment Share on other sites More sharing options...
Josh Posted September 6, 2011 Share Posted September 6, 2011 It can be used to justify the claim that certain bourbons are "pot still", like A. H. Hirsch (nee Michter's) and Willett Pot Still Reserve.The makers of Willet Pot Still have indicated that they in no way mean to imply that that product was made in a pot still. It just happens to be the shape of the bottle. It's a sort of homage to the pot still. Link to comment Share on other sites More sharing options...
p_elliott Posted September 6, 2011 Share Posted September 6, 2011 The makers of Willet Pot Still have indicated that they in no way mean to imply that that product was made in a pot still. It just happens to be the shape of the bottle. It's a sort of homage to the pot still.Maybe it means they will get off the pot and make their own whiskey one day. Link to comment Share on other sites More sharing options...
T Comp Posted September 6, 2011 Share Posted September 6, 2011 But just as Randy has a chemical engineer inside him, I most definitely do not, so my ability to explain this stuff technically is limited.And my ability to even understand all this stuff is limited but I...still... keep trying :grin: Link to comment Share on other sites More sharing options...
Tom Troland Posted September 6, 2011 Share Posted September 6, 2011 Josh - Your comment about the bottlers of Willett Pot Still Reserve is effectively untrue. Nowhere on the bottle and nowhere on the KBD website is there any indication that the bourbon is not a pot still product. So, no, KBD has not been forthcoming about this matter. While a number of their bottlings are very good, they have always coyly implied in their labeling and promotion that they are an actual distillery. The name KBD says it all. Perhaps the KBD folks have occasionally intimated to gurus like you that Pot Still Reserve is no such thing. But how is a novice like me, or the average Joe the Plumber in the liquor store to know? Link to comment Share on other sites More sharing options...
Josh Posted September 6, 2011 Share Posted September 6, 2011 Josh - Your comment about the bottlers of Willett Pot Still Reserve is effectively untrue. Nowhere on the bottle and nowhere on the KBD website is there any indication that the bourbon is not a pot still product. So, no, KBD has not been forthcoming about this matter. While a number of their bottlings are very good, they have always coyly implied in their labeling and promotion that they are an actual distillery. The name KBD says it all. Perhaps the KBD folks have occasionally intimated to gurus like you that Pot Still Reserve is no such thing. But how is a novice like me, or the average Joe the Plumber in the liquor store to know?Excellent question. Link to comment Share on other sites More sharing options...
smokinjoe Posted September 6, 2011 Share Posted September 6, 2011 The makers of Willet Pot Still have indicated that they in no way mean to imply that that product was made in a pot still. It just happens to be the shape of the bottle. It's a sort of homage to the pot still.I thought that bottle was a bong... Link to comment Share on other sites More sharing options...
Gillman Posted September 6, 2011 Share Posted September 6, 2011 Good discussions. In the usual doubler set-up, surely there is excess liquid drained out, this would be water and some of the low and high boiling congeners that stay back with the H2O to help polish the spirit as Chuck said. Either the tank is emptied after a few days or it is drained out continuously. I get Tom's point that how can it be drained if you would lose the alcohol in the stream feeding continuously in the tank? But I would think they must drain it at intervals before boosting the temperature to reboil the low wines. Once the boil is down when the residue is mostly water not alcohol, that is when it must be flushed. Again I don't know for certain but would project this based on what I do know. If I am wrong by all means I appreciate corrections.Also, continuous stills don't truly operate forever, they are stopped every week or so I understand for cleaning and maintenance. A doubler is definitely a spirit still, in function it does exactly what a Scots spirit still does.Thad: this is not complex really - not the math or the other background technics Randy knows, but the general concepts: to be discussed soon I hope in person.Gary Link to comment Share on other sites More sharing options...
Tom Troland Posted September 6, 2011 Share Posted September 6, 2011 Gary - Thanks for further insights. Looks like this is a question for Jim Rutledge or Harlen Wheatley or Jimmy Russell or one of their colleagues. I did a Google search on "pot still doubler". I found an old straightbourbon.com thread on the topic from July 2000. Chuck described a pot still doubler as "simply a tank with a lot of pipes running into and out of it". I think we can all agree on that! Chuck also said, "Although it is, in fact, a pot still it does not have the classic appearance of one." My vague impression of seeing the doubler at Four Roses is just the opposite. It did look to me like a classic pot still. But, if we understand things well, the doubler does not actually function much like a pot still. Obviously, we don't understand things well! Or at least I don't. I like being in this situation because it means I will eventually learn something interesting. Link to comment Share on other sites More sharing options...
Gillman Posted September 6, 2011 Share Posted September 6, 2011 Tom, you are right that some doubling is merely a re-charge of a traditional alembic still. E.g., this is what happens in Virginia when white dog from Buffalo Trace is polished to make the final dog that will be barreled (at the Virginia Gentleman plant). So you can use a "real" pot still although I believe the one at Four Roses is connected by piping to the column still.Gary Link to comment Share on other sites More sharing options...
cowdery Posted September 7, 2011 Share Posted September 7, 2011 Speaking of Michter's, I learned today, indirectly from Dick Stoll, that the doubler at Michter's was used more like a true spirit still in that doubling was a completely separate operation, done with fully condensed low wines (which out of a column still aren't that low) on a different day even, taking heads and tails cuts, which you can't do with a continuous doubler. In that sense it was a 'pot still' operation different from what most other distilleries were doing.Every major producer distiller I've ever talked to about doubling has described the doubler as a pot still. Appearance is certainly not the point. I can imagine a continuous batch process, though that sounds contradictory. It's all a matter of timing, but I'm not sure if what I'm imagining is what they do.Cooking and fermentation are batch processes, for example, but they are timed to feed the beer well continuously.Because the term 'pot still' has been so generally debased, I tend to use the term 'alembic' to describe what most people, especially lay people, mean when they say 'pot still.' Probably 99% of the people who claim they use 'pot stills' cannot call what they use an alembic. Link to comment Share on other sites More sharing options...
Gillman Posted September 7, 2011 Share Posted September 7, 2011 Just one other point is that I recall reading or hearing of a low wines tank. This would entail condensing the low wines and holding them for a time (even as the tank if large enough is being topped up from the beer still), after which the low wines are sent to the doubler. You could control in other words the flow of low wines to the doubler and thus permit the spent beer in the latter to be piped out before a new charge is received. I confess when you read about removal of slops to separate the solids they don't talk about a doubler or thumper but I think there has to be a stream from it. How else could the proof go up?Gary Link to comment Share on other sites More sharing options...
tmckenzie Posted September 7, 2011 Share Posted September 7, 2011 I think it is like a lot of things in the whiskey business. Each person has his onw name for something. The only way I can make a continuos doubler make since is it is the same as a thumper. As far as a heads and tails tank, I learned this from my visit out to Steve Nallys place, that you make you heads cut when the column and doubler are all up to operating temperature. Anything before the cut is sent to the heads and tails tank, and when they start shutting the column and doubler down for the day, what comes off goes to it as well. At least I think I am right. When we get one, I will figure it out. One interesting note I might add about Wyoming Whiskey, is the elevation they are at. It took Steve a while to get his setup to run right he said because of the boiling point of water where they are at. Link to comment Share on other sites More sharing options...
White Dog Posted September 8, 2011 Share Posted September 8, 2011 Let's be clear. KBD is none of our f--kin' business.:cool: Link to comment Share on other sites More sharing options...
cowdery Posted September 12, 2011 Share Posted September 12, 2011 It looks like Alltech is planning a facility in Lexington similar to the PS one. This is from Friday's Lexington Herald-Leader. Supposedly, they've been making bourbon in their current facility for the last four years, which is aging somewhere in Bardstown. Hummmmmm. Link to comment Share on other sites More sharing options...
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