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Pot Still advice sought from you seasoned professionals!

Long time lurker, first time poster, so be gentle with me!

I want to start distilling. Mainly for the purpose of experiments in rum (the big dunder thread is a treasure trove of good information! ) and I am a serious rum geek, but first I think a few basic white spirits runs are in order to hone my technique and equipment, which I’ve yet to purchase, hence this thread. I know and understand a lot about the process of distilling but no real practical experience, I have however been a brewer for nearly 20 years and happy with my RIMs and HERMS brewing equipment I’ve built from scratch so this is a step up.

My question is on pot stills and the lack of copper in the vapour path. Obviously I can pack the upright with copper scrubbers but that will add reflux, and some of you will no doubt tell me this is the best option so happy to go this way, but for a simple pot still with 2” parts, would a 4” or 16” copper tube upright fitted with ferrules from the boiler be sufficient to counteract sulphur and neutralise other volatiles?

What I love about the still dragon parts is the fact the are so modular, and I want to experiment with different configurations, such as the length of the upright before the condenser to play around with lighter/heavier spirits, and adding a torpedo section and deph condenser in the future which I know would have sufficient copper to deal with sulphur etc.

Ultimately I’m thinking of the basic pot still configuration with various bends and copper uprights in varying lengths to get a good, solid understanding before I start adding shiny toys ;)

Any advice from the pro’s would be highly appreciated!!!


  • Well I'm not a professiona but if you want my advice on learning the hobby I would say start simple and figure out the basics. It will pay off in the long run. Just my $.02.

  • Hi @DunderHeid and welcome from a potstiller from way back.

    As far as copper in the vapour path it's used to correct faults in the wash ie sulphides. If you don't have the faults you don't need the copper.
    Assuming you do get a few sulphides from yeast stress or whatever then only a small amount of copper is needed and that can be, as you say, a roll of mesh or a few pieces of copper on a filter disc at the bottom of the riser.

    The small amount of reflux you'll get without a dephlamtor will make no discernible difference, maybe lift your output a point.

    In short, don't fear the stainless.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • edited October 2017

    Normally we think of copper's ability to remove sulfides from the product as the reason for using copper. While that probably is true not everyone has a problem with sulfides in their product, and the amount of copper in a stainless boiler with copper riser and condenser, all unpacked, has been plenty to keep any of my product free from sulfides. Even with my newer condenser design utilizing a stainless core in a copper tube, I've never experienced product sulfides.

    While all of my experience up until about 2.5 years ago was as an amateur, since that time I've run a buttload of whisky through Cultus Bay Distillery's old reliable potstill, and customers love the flavor and smoothness, both white at 110 proof and 6-month-oaked at 86 proof. The same still also produces low wines for the vodka still, and while our vodka has a hint of a malt note to it its flavor and smoothness are what sells it.


    Since my interest lies in large part with whiskeys, Irish, Scotch, or American, I've always looked up to the best of those for process and equipment, and my favorites in those classifications are all produced on potstills, so there's never been any question for me about what kind of still to make whiskey (or rum, or brandy, or especially grappa).

    600 x 800 - 79K

    Zymurgy Bob, a simple potstiller

    my book, Making Fine Spirits

  • It's no problem to pick up a few copper EZ Flanges to incorporate some "modular" copper tubing into your vapor path.

    StillDragon North America - Your StillDragon® Distributor for North America

  • It is if he's in Australia.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • edited October 2017

    Looks like a modified Walking Wolf design there @zymurgybob. My home made 2"er is very similar to that, although it has been relegated to being a stripper since I use my SD 4"er as my pot still now. I put one plate in (and no deflegmator) when it's in pot still mode - just for copper contact.

    A wash made from brown sugar makes a nice silver rum. Toss a few mole asses into the ferment to up the rumminess a notch or two.

    I'm more like I am now than I was before.

  • Excellent, thank you very much gents! I’ve worked in the scotch whisky industry for 12 years and it’s always copper pot stills and how you can’t use anything else, so I’m probably jaded ;) Love the modular still system though, so much ability to play around with any sort of still shape and dynamics with a few simple changes. Good tip on the filter plate and copper pieces though punkin. Will add one to my order just in case! Many thanks again to all of you, appreciate the advice from all!!

  • @DunderHeid said: Excellent, thank you very much gents! I’ve worked in the scotch whisky industry for 12 years and it’s always copper pot stills and how you can’t use anything else, so I’m probably jaded ;)

    Maybe we could pick your brain a bit? I'm not sure what I've got to swap, but I'll think of something.

    Zymurgy Bob, a simple potstiller

    my book, Making Fine Spirits

  • edited October 2017

    By all means! I’m mainly in legal compliance but always pestering our still men for technical details as I’m a geek like that!!

  • HI @DunderHeid, I'd be keen to hear about mash grain bills and water chemistry used in commercial scotch distilleries.

    If you can shed any light that'd be great - oh anything on Oak selection would be cool too ;)

  • My interests lie in what goes into the first still, what goes into the second still, and what's cut when. Like Crozdog, any light's great, even if it's at the end of the tunnel.

    Zymurgy Bob, a simple potstiller

    my book, Making Fine Spirits

  • edited October 2017

    Now here’s something I can add to the discussion!

    As far as water chemistry goes, most distilleries take straight up tap water, or spring water, filtered for chlorine in the case of tap water. I’m not aware of any of our distilleries using salts or minerals to tinker with water chemistry but to be on the safe side, I will check. The only time water chemistry is a factor is for reduction of spirit. For that we all use demineralised (demin) water. Additives in the wash backs (fermenters) will only ever be anti foam (PPG) and the same in the stills.

    Most distilleries will reduce to 63.5% before cask filling. This allows for uniform maturation across thousands of casks, but even the smaller, independent single distilleries do this. It’s a “standard” practise, Dornoch Distillery is tiny, but even they use this method. Reduction to bottling strength also uses demin water. No other additives other than E150a plain caramel colour.

    For cask selection, the Scots are tight arses ;) we almost exclusively use ex-bourbon casks. The big boys, Diageo, Chivas, Edrington and William Grants will buy direct from US distillers. The rest will normally source through third parties such as the Speyside cooperage as they don’t have the buying power to deal direct.

    The use of casks on the other hand is very selective as to what is being produced, as a cask will be used generally 4-5 times, so could easily have a 12-50 year life (Scotch ain’t Scotch till it’s been in wood 3 years so the shortest life cycle for a 4 use cask is 12 years) Single malt whiskies will generally go to first fill bourbon, or 2nd fill casks if the blenders want a lesser oak/vanilla profile. Cheaper blends that will be a 3 year old product will be 2nd or 3rd fill casks. Grain whisky, which is generally seen as a filler/bulking product for blended whiskies, almost always go to 4th or 5th fill casks. I’m not aware of any of the big boys using casks more than 4 times, 5 at a push.

    There are obviously exceptions to this. Premium blends may well use first fill single malt whiskies in various amounts for the flavour profile the blenders want, and grain will be put to first fill casks for bottlings if single grain whisky, but these are rare, and also to be used in really high end blended products. Other casks are generally used for finishing whisky. Madeira casks, sherry casks, wine barrels or rum casks to get a certain profile. It’s rare that a whisky will be aged exclusively in such a cask. They product is normally racked into finishing casks for a 6-24 month period till the flavour profile is obtained.

    Casks are always oak. It’s the law. But at least 90% of the casks used in the scotch whisky industry are ex-bourbon, so if you want more detail on the wood, go ask Brown Forman and the likes ;)

    I’ll come back to grain bills and stills shortly.

  • edited October 2017

    Mash bills and yeast in the case of the big boys is generally a very basic thing. Because of their buying power they’ll take the same for most distilleries. Gone are the days of each distillery using specific malts, these days efficiency and extraction rates are king. Same with yeast I’m afraid.

    Mauri Distillers yeast is very typical within the industry, but for me to give specifics on volumes, pitch rates and yeast count would land me in trouble as these are closely guarded secrets and I’d be sacked for divulging these! I could work up some basics though so will get back to you.

    Malt wise, it’s barley. Obviously. For grain whisky most use wheat and a portion or malted barley for enzymes. Some do experiment with rye and other grains though. I know one smaller distiller is playing around with very high ratios or rye for its grain whisky as a separate product that will likely be bottled as a single grain whisky. There is very little room for innovation in whisky so this could be a winner for them as few others will bother.

    I used to work for one of the main malting companies so will dig out some historical details on malt types. But these days as I said, it’s about efficiency than anything else. Crisps is a large supplier in the whisky industry. You can glean a good bit of info from their site.

    A typical mash bill would result in a wash normally no higher than 8%, and within a few days of fermentation. some of the big boys will pump to the stills at their required abv in the wash backs regardless of whether the wash is finished fermenting if it’s going to overshoot for whatever reason, but normally they are spot on with their gravities. It’s an industrial process and one they have to a fine art for consistency of product.

    Again giving details on my distilleries cuts in the stills would land me in bother but will try and work up some basics for you. Basic stuff though, a wash run is loaded to a low wines receiver (tank). Normally the out put from 2 wash runs will go to a spirit run. Spirit runs you’d expect an output around 65-66%

    One interesting thing you may find though is that some of the big boys will grade their days production against a library standard. There could be 5-8 grades depending on the company. The top grades go to single malt whisky if the distillery produces one. Other grades will be earmarked for blends or bulk volume spirit sold to other producers, and this grading takes place before it goes to cask, so they can decide what sort of casks to use for the spirit and the final product.

    This has the purpose of also identifying how a distillery is performing against the standards set for it based on labs analysis of the grain and yeasr they are using (big brother is always watching!) They maybe be getting the volume they are told to produce, but the quality could be poor based on bad cuts.

    But again, this is an indistrial process these days and most is automated through inline flow meters and alcometers, but I know of one distillery in a large group where the distillery manager can tell you who was on shift based purely on nosing the final spirit from That shifts production, as each still man likes his own parameters within the tolerance set by the manager (which are pretty tight), and the distillery is largely manually operated.

  • Crozdog: for specific water chemistry pick a distillery and we could likely find the local water profile from Scottish water. It’s highly unlikely it’s treated with additional minerals and salts, but I can find out in most cases ;)

  • Great info mate.

    Thanks heaps. looking forward to anything else you can divulge without getting fired

  • One thing I can say about the cuts, is that it’s all done on abv percentages in the spirit runs. The still men don’t have direct access to the spirit, as back in the old days everything from the stills went through a spirit safe and that was double locked. The distillery mamanger has one key, the excise men (HMRC) had the other key. Spirit safes allow the flow of spirit to be diverted to low wines, fients or spirit receivers, plus there is a built in system for using an old fashioned hydrometer/alcometer to check against the automated inline sensors. These days HMRC are removed from the process but for the sake of tradition the safes are still common place.

    The big distilleries cuts are based purely on abv. This leads to the issue of spirit quality and why they grade their spirit before casking.

    Backset is always used, but most pot-ale (backset) is sold off to feed producers, and fients (heads and tales) and sold off too, to third party producers of other products. Cuts and backset proportions are generally distillery specific.

  • I would like to know more about how farmers would use backset... I throw all whiskey backset out and also 50% or more of rum backset out... I have neighboring brewers that have farmers come pick up the spent grain, but backset might of interest to them, but I do not know how to evangelize its use

  • Great read mate, thank you. Interesting to read that feints are not 100% recycled as that is the common belief as far as i understand it and what i have read in discussions.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • edited October 2017

    Yeah super good read. Really do appreciate your contribution. Thank you.

    Couple things in there I wasn't expecting and also nice to read things that confirm one's point of view about a few things.

    Could you comment on approximately how much (%) yield a "typical" distillery could expect out of X liters of beer?

    StillDragon North America - Your StillDragon® Distributor for North America

  • Sorry, I should clarify on the fients side of this. Heads and tails get recycled, the nasty stuff is sold off, fusel oils etc. There’s money to be made in that. Some of the big distillers are part of a co-op in a feed plant that produces animal feed, pot and draf is used for this.

    I believe some farms use pot ale at the same time as muck spreading their fields but we don’t supply to this. However there are a lot of other uses, including some trials in using potable for biofuels, and even pellet food for salmon farms.

    I’ll see what I can dig out on yields for you Smaug.

  • edited October 2017

    I thought most big scot distilleries used dry houses to concentrate wet (thin) stillage into DDGS (grain solids mixed with evaporated stillage).

  • DDGS = Dried Distillers Grains with Solubles

  • edited October 2017

    @DunderHeid said: I believe some farms use pot ale at the same time as muck spreading their fields but we don’t supply to this.

    I'm almost positive this is also what the Brazilians (cachaca distilleries) do. All goes back to the cane fields.

    StillDragon North America - Your StillDragon® Distributor for North America

  • edited October 2017

    Some do @grim, but some don’t have space for the facilities on site due to the old nature of the buildings. There’s a grain whisky distillery in Glasgow which has its own grain processing plant on site, where they dehydrate the spent grain, compress into pellets and dispatch direct from the distillery.

  • Bit of an aside to the topic, with all the safety focus being on the distilling process, it's interesting to note that the top two reasons distilleries burn down are Malting and Drying, not distilling, not storage.

  • @grim : thanks, you made my day :))

  • edited October 2017

    A bit late, but thanks @DunderHeid for all the information. I've always suspected that at least the Islay distillers use spring water (which I think in those cases means peat bog water), and watching the Bruichladdich videos, they show a jar of "process water" looking pretty murky. Any chance those guys proof with bog water?

    Zymurgy Bob, a simple potstiller

    my book, Making Fine Spirits

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