Another experimental Rum

[der wo]

A new Rum is fermenting just right now. It will be a triple potstilled all molasses Rum with high ester count. I will write a few posts about the process within the next weeks.

[der wo]

Chapter 1:
Wash preparation

Inspired by Arroyo I used boiling water to prepare the wash. He writes much about evaporating foul smelling substances and falling out gums. He uses a centrifuge for filtering, I don't have one. But I will see, perhaps something falls out. It's an experiment. A change should be measurable with my hydrometer (lower OG and lower FG). If it's not only a change, but a success in flavor, will be much harder to define. I don't make a direct comparision.
A downside of using boiling water could be an evaporation of esters and acids. Arroyo rises the pH with lime to avoid this evaporation. He writes that foul odors will evaporate at high pH, esters and acids not, because they form a salt at higher pH. Whatever. It's very plausible chemically and I already have done an experiment, where I think I have proved it in general (neutralizing the odor of vinegar with lime and awakening it again with sulphuric acid). If it really betters the flavor of a molasses wash, who knows. And of course, only because Arroyo liked this flavor, I don't know if I will like it.

I have 20l blackstrap molasses. With one liter I already have made vinegar. See this thread:
viewtopic.php?f=7&t=70788
And I want to save up two more liters for further experiments.
So 17l molasses (around 24kg) were in my fermenter and I made it up to 67l with boiling water. In this water I had solved 5tbsp lime (calcium hydroxide) and 25ml concentrated sulfuric acid before. PH is 7.0. Arroyo recommends a less drastic rise of pH. Whatever. I then let cool it down 12h naturally and with open lid. Then I siphoned the wash through a BIAB in a few buckets to look if there is a sediment to discard at the bottom. Unfortunately no sediment was formed. And of course the SG didn't change. Did the boiling water improve the smell? I think yes, it did. But all in all I think the experiment is failed. This doesn't mean, Arroyo is wrong, it means only that it's not possible to clarify molasses easy way.
OG is 1.109. I think I'll get 9.5%abv.

[ShineonCrazyDiamond]

Der woo, I'm glad to see this. Ive seen alot of your experiments, but I will admit the chemistry side is not my strongest. So it is nice to see one of your complete processes. In fact, I must have missed the part about boiling water to remove compounds. Learned something already. I always do, anyways, as a matter of ease to dissolve the vitamins and molasses. Cool to learn about the other benefit.

Thanks for the thread.

[der wo]

Yes, thanks, I don't think someone has written much about molasses clarifying here.
But when you have read everything available from Arroyo, it's interesting, that he had the most interest in analyzing the quality of molasses and trying to improve them. The heavy ester thing is only a small part of his studies. His dream was to be be able to distill down to barrel strength with a batch column still single run. Including a fifth fraction (after the tails). And he thought that mainly the preperation of the molasses is the key.
The question is, if the today molasses is already more clarified than th molasses 80 years ago. Because he has published analytical results (gum, ash, minerals and so on) of many different molasses from different countries, I can compare it with the label of my molasses. And as far as I am able to evaluate it, it's still the same. It looks like nothing has changed.
That's why I thought, here is something to try out.

[Yummyrum]

Hope it goes well Der wo .
I agree about the pH adjusting and boiling does bugger all in regards to Clarifying . As seen in my experiment Here.
I got almost no change in SG or amount of visible flocculation .

I did notice a difference in taste which I put down to the Lime but I am not really up with all this Rum ester stuff .

[der wo]

Thanks yummyrum,
I haven't found this thread before. So you did something similar already five years ago. Also without success like me. I think I used not enough heat and I would need a centrifuge.
You write there much about the poor solubility of lime and limewater. I simply throw the powder into the wash and stir. Then I wait an hour and stir again. I have a copper pipe for stirring in my fermenter all the time. I am not sure, but I think everything gets into solution. Also the CO² helps probably much.

[der wo]

yummyrum,
because I will have much lime in my ferment, probably the sulphuric acid addition will cause much calcium sulfate to fall out. Do you think it's good to have it in the boiler or should I siphon it off? Not because of the calcium sulphate. But perhaps there are oher substances (good or bad) in the sediment?

[Yummyrum]

I can't say if its an issue in the boiler or not der wo . I made several full size batches of this and it all sat in the fermenters for a week or more after fermenting so there was a hard yeast cake and sediment layer when I drew off through the tap .
I suspect that most stuff settled out by then that was going to.

I found that the Rum left a strange taste on the palette . It reminds me of Pussers Navel Rum . Whether they use these chemicals too I have know idea or even if the taste is related but I got it with each batch I made using this process.
Incidentally I used a pot still when I did it .
I also used Hydrochloric acid whereas you are using Sulfuric .... how much difference this will make I have no idea

Regarding Calcium hydroxide , it is concidered insoluble in water . Most will just settle out and sink to the bottom . Sodium hydroxide however is very soluble .
Regardless of it solubility it does raise the pH ... it is what it is when you measure it

I'll also mention here that anyone concidering attempting this should be well aware of the dangers of using Calcium Hydroxide and concentatrated acids such as Hydrochloric ir Sulfuric .
Consult the relavant SDS of each and use safe handling and storage .
Wear safety goggles as a bare minimum .
When diluting acids Always add acid to water ...... never add water to acid

[der wo]

Lime is not very soluble in water. But in (acidic) wash it is better. Depends on the acidiy. But anyway, afterwards I think, that caustic soda would be better than lime perhaps. At least worth to try. Not only because of the solubility, but mainly because it simply needs much less of it.

I wouldn't use hydrochloric acid, because it has a smell. On the other hand the little amounts it needs, I don't think it's smellable.

Yes, safety warnings. Of course you are right. I have become lazy to mention it at least once in every thread where I use such chemicals.

I will do several stripping runs. Perhaps something like with the sediment vs without will find a place.

[distiller_dresden]

Hey der wo, maybe you should try the same using some very low quality molasses to imitate perhaps what he had back then? Like feed store/animal grade molasses? Just spit-balling. I think that would definitely have a lot more 'undesirable' stuff in it, and perhaps back then their processing method for molasses was certainly less complex and developed, plus much less technology and technique, than what we have today. Of course, you'd also have a lower sugar content, so... Six of one...

[der wo]

As far as I know is my molasses "low quality". It's for making fertilizer. Much minerals, low sugar.

The question is, if the today molasses is already more clarified than th molasses 80 years ago. Because he has published analytical results (gum, ash, minerals and so on) of many different molasses from different countries, I can compare it with the label of my molasses. And as far as I am able to evaluate it, it's still the same. It looks like nothing has changed.

And Arroyo was able to improve also the "good molasses", not only the bad ones wih this method. I am not sure. But I will not try again clarifying this way probably.
From small experiments I did the last days it looks like the sulphuric acid will cause to fall out not only the calcium. In a positive way I think.

[NZChris]

Hey der wo, maybe you should try the same using some very low quality molasses to imitate perhaps what he had back then? Like feed store/animal grade molasses? Just spit-balling. I think that would definitely have a lot more 'undesirable' stuff in it, and perhaps back then their processing method for molasses was certainly less complex and developed, plus much less technology and technique, than what we have today. Of course, you'd also have a lower sugar content, so... Six of one...

Shit in, shit out. If molasses tastes bad when you lick it off your finger, the chances of you making nice rum out of it with a ferment and a couple of distillations are bugger all. Stockfood, culinary, whatever, taste it before you get your wallet out.

[der wo]

Yes. But what means "bad"? For example bitterness means high mineral content and perhaps low sugar content. This is not bad. But sulphuric or mold is bad probably.

Anyway, industrial scale it makes sense to be able to work as best as possible with every quality which is available. He never claimed he could make superior molasses from poor quality molasses. He claimed he could make all qualities significantly better. Mediocre from poor quality for example. And also further improve superior quality.

And we homedistillers? At least for me it's not possible to buy cane molasses in a store and taste it before buying. I only can decide after buying, that I have wasted my money.

[NZChris]

The last time I bought molasses, I stuck my finger in it, had a taste, then bought twice as much as I had intended to

[der wo]

Chapter 2:
Main fermentation

I decided to use an egg for yeast nutrients. In theory adding nitrogen this way instead with for example DAP or fertilizer should rise the fusel alcohols. And fusel alcohols produce interesting esters.
I hydrated three blocks fresh bakers yeast (each 40g) and started the ferment at around 27°C. I wanted to start it hotter, but the wash had cooled down faster than I thought.
I expected a fast pH drop, so I measured very often in the first stage of fermentation and added all in all 12tbsp lime in the first 24h to hold the pH at around 6.0. It's funny, I have developed the superpower to measure the pH with my nose now: When it starts to smell nice fruity, the pH has dropped down. When it smells only like licorice and chocolate, it's still high enough. It's very obvious that the high pH keeps the flavors/acids/esters in the fermenter.
Off topic: Two fruit ferments, one with low pH and slow cold fermentation like it's normally done, the other with high pH and fast fermentation and lowering the pH direct before distilling, would be a great experiment IMO. Why fruit? Because fruit has -different than molasses or grain- many fruity esters on its own, no need and no interest to produce some by yeast or bacteria, and perhaps high pH keeps more of them in the fermenter. Why fast fermentation at high pH? Because a slow fermentation at high pH would invite bacterias, and this would end with something no one needs like an apple brandy with strange pineapple note perhaps.

It fermented slow. Perhaps because of the pH corrections all the time? Or because I fermented without fertilizer? I normally use fertilizer for every ferment. And it was colder than the forecast. After 3 days only 5%abv. I already had added 300g lime at this point. If I hadn't tried out the hot clarifying, I wouldn't have needed the sulfuric acid to bring the pH down a bit before adding the yeast. Now the sulphuric acid causes, that I have to use more lime... And then before distilling more sulphuric acid... Next time (without clarifying) without sulfuric acid from the beginning it would need a bit less lime. Or I would use caustic soda instead of lime perhaps. Much less would hold the pH high.

When the fermentation was almost finished, I added some cheese with holes for a bit lacto and propionic infection. Also to my vinegar washes. I think I will have more than enough butyric infection, so I try to move it in other directions.

From time to time I make a sulfuric acid flavor test:
-20ml wash
-10ml 95% ethanol
-0.5ml sulfuric acid
in this order. The sulphuric acid is always the last ingredient. Never pour something onto sulfuric acid.
Then I close the lid, shake it a few times and wait a few hours. Calcium sulfate will settle out. Then I open the lid and the smell will tell me much about the ester profile of the Rum. Especially a vinegar infection (glue smell) is easy to detect.
PH 6 and opening the fermenter such often for stirring lime in is dangerous. There is not much control over infections this way. I don't know when a vinegar infection takes over. This makes this test important.

BTW, this Rum will be without or only little dunder usage. Why? Because in a way dunder dilutes flavor. At least the original molasses flavor is already stripped out. So adding dunder to wash or low wines would dilute this flavor. So I use infected wash or turned to vinegar wash instead of dunder. Here all molasses flavor is still there.
But I will keep and infect some dunder, just for sure. I will use it only, if something goes wrong.

With my small potstill I will do six very deep down stripping runs. Each one different. Something like different pH levels, with or without calcium sulphate sediment, vinegar additions, prolonged fermentation, yeast bed run.

[der wo]

Chapter 3:
Stripping runs

Due to circumstances I had to do all the stripping runs in two days. So I didn't make the long fermentation experiment. And it would have been dangerous, because when fermenting at high pH the acids (also vinegar!) isn't smellable anymore. And I didn't trust the sulfuric acid flavor test 100%.

It needed much sulfuric acid to lower the pH, because I already had stirred in so much lime. I experimented with 0.5 - 1% sulphuric acid (5 - 10ml per liter wash). This lowered the pH to 4.2 - 3.5. Not really extreme low levels. But I ran out sulfuric acid unfortunately. After adding sulfuric acid a sediment forms very fast. It's very compact, easy to siphon off. PH 4.2 had a sediment of 800ml per 10l wash, pH 3.5 1.5l per 10l wash.
The first two strips were at pH 4.2. The first one stripped with sediment, the second without. Either because of the pH treatment or because I had added butter already during fermentation, I was able to strip it as fast as a birdwatchers. But I wasn't very happy with the flavor: Much fruits and a very acidic taste (but those acids should form esters next distillation). Only litte Rum and molasses flavor. The one without the sediment was a bit better. Cleaner, but same complexity. So I decided to strip the remaining wash without the sediment.
The other strips at lower pH were much better. Much Rum and molasses flavor. And even a higher acidity (I am not sure, what exactly it will do with the Rum...). Sad that I had no sulfuric acid left for runs at 3.0 or even lower. I am very happy with the runs at 3.7 and 3.5, but who knows, what I would have got with lower pH.
The "yeast bed run" was no real yeast bed run, because of course the yeast settled together with the calcium sulphate to the bottom. But -surprise!- those low wines turned out best: More pleasant flavor without downsides like musty yeast smell or something. And the dunder of this strip was by far the best dunder I ever got. So I decided to keep it and use it in the middle runs. Probably uninfected, because I have enough acids I think. The low wines are between pH 3.2 and 3.0! The lower the pH of the wash, the lower the pH of the low wines. And I don't want again add lime in it, and then more and more sulfuric acid. The pH of the dunder is 3.3. I don't think it will get strong infected much without rising it.
I collected per 10l wash 4.6l low wines. This way the low wines are only slightly over 20%abv. The dry wash had almost 9.5%abv. This high yield tells me, that I didn't had much vinegar, despite of the high pH and the very unsterile process. Probably the high gravity prevented it.

My options for the middle runs:
- Shall I use the not so interesting strips at 4.2pH or should I make neutral alcohol from it? I will give the low wines a bit time to develop and I make some sulfuric acid flavor tests.
- What mixture of fresh molasses, dunder, homemade vinegar and vinegar should I add to the middle runs? Difficult to decide. But I will have two middle runs. So I can make changes the second run.
- How far down should I distill it? I think at least to 0%abv. But perhaps further?

Conclusion so far:
Lime treatment is worth it. The flavor potential of this method is huge. But probably in a different way: Adding lime only at the main fermentation when the CO² pushs out much flavor. Later when not much CO² anymore but many acids are produced, letting the pH drop down. Then it needs way less sulfuric acid and the sediment will be much smaller. Unfortunately I didn't find out what the optimal pH is for distilling. Probably lower than 3.5.

[Shine0n]

Thanks der wo, interesting to know about the ph levels and it effects.

I have an all molasses wash sitting for 2.5 weeks now and I'm working out of town, I'll not be returning for 2 more weeks and I've been wondering about my wash and how it will be with such long fermentation and being open to the air. Ph drop (much) possible vinegar? infections?

I do not know the status of it now but I guess now I'll find out the benefits of a long hot fermentation that's open. It's been in the mid 90f days and some cooler nights 65f

Sorry if I missed or skipped over the times but how long are you fermenting for with these experiments?

[Bushman]

Thanks for doing this der wo I found this a very interesting read. Like Yummyrum it makes me wish my chemistry background was a bit stronger. I need to go back and re-look at my rum recipe as I do a blackstrap molasses and Panela wash. It makes it a little lighter rum but because blackstrap is low in sugar content I thought and think the panela with all its nutrients adds to the over all taste profile. What I am interested in is comparing your method of heating the molasses to mine and also rethinking the ratio of molasses to panela.

[der wo]

ShieneOn,

I let it ferment only until it was done. In this case (all molasses - high gravity, high sugar/abv, no DAP or fertilizer, warm but not hot temp) it needed 2 weeks and there were no signs of infections. But many esters. This is what makes this process very special. At least no vinegar infection. The esters smell a bit like lactic. I am unsure if those esters are yeast or bacteria caused.

Because AFAIK your wash aims for a lower abv than mine and has sugar added (lower SG), it's more likely to get infected by vinegar. As always low temp and low pH would help to keep the ferment uninfected.
A pH drop is not necessarily vinegar caused. It's just normal, that the pH drops. And how much depends also much on the buffer capacity of your mashing water and if you add something like oyster shells..

I only once had a wash turned really heavy to vinegar. Long time ago. All grain Malt Whisky. I dumped it unfortunately. Perhaps it would have been something interesting. I can't tell you much about it, sorry.

What abv does your ferment have? What was the OG?

[der wo]

What I am interested in is comparing your method of heating the molasses to mine

Why do you heat it? Only because the molasses solve easier? Or did you recognize some positive effects on taste or fermentablity?
I think my heating process was a waste of time.

[Bushman]

Currently at our condo and don't have those numbers but can get them next week when I am home and can look at my notes. I know I bought a Refractometer just for the rum to get a more accurate reading.

[Shine0n]

Actually it's an all molasses wash at 19 brix which is 10.8% potential abv, no nutes but I did boil 15 gal of water to help dissolve the moll. It's also 45 gallons.

I'm not sure the amount of boiling water and the short length of time there have any significant effects on the wash nor did I syphon off.

I guess I'll find out the results in 2 weeks.

I have left 7 gal of molasses (84lb) I'm going to work with when I return and I may try some clearing of it to see if I can find an improvement in quality. It's blackstrap fyi

Edit, I just seen you said heating was a waste of your time

[der wo]

The one without the sediment was a bit better. Cleaner, but same complexity. So I decided to strip the remaining wash without the sediment.

And that's why I will not experiment with using caustic soda instead of lime. With lime I get calcium sulfate, which is unsoluble and settles out. With caustic soda I would get sodium sulfate, which is way better soluble and will probably stay in solution.

[der wo]

Chapter 4:
Middle runs

Perhaps here first a bit about triple runs: The idea is to get more flavor with a triple run than with a double run. Sounds strange? Here is why it's not: A double potstill run forces to finish the stripping early or the abv of the spirit run will be too low for a good quality enough clean new make. Stripping early reduces flavor. The hearts of the spirit run of a double run have to finished early or the tails will overwhelme the flavor. Finishing early reduces flavor. Of course hearts from a double run with 75%abv will have more flavor than hearts with 80%abv from a triple run. But what's with hearts with 70%abv from a triple run? This is the question. Three tails cuts vs two tails cuts. Three times cutting little (leaving little in the boiler) vs two times cutting much. Comparing double runs vs single runs (both with a reflux still) the double run wins always for me. So perhaps the triple run wins against the double run.

Because my low wines unfortunately are different quality, I decided to make one good and safe middle run with the good low wines (from 3 of 5 strips) and one experimental one with the worse ones. Only little additives to the good low wines and much to the worse ones. And perhaps I will do the spirit run only with the good high wines. Or perhaps I use only special fractions of the worse run at the spirit run too.

First middle run (good low wines, only little additives):
15.9l low wines at 20.5%abv. I added two days before distilling:
-100ml vinegar essence (20% acetic acid)
-100ml homemade molasses vinegar (unknown acid content)
-50ml homemade molasses vinegar, which has already turned to a butyric ferment
-100ml uninfected dunder
-150ml fresh molasses
Then I lowered the pH to 2.6 It needed 30ml sulphuric acid.
Because of the lime I added to the homemade vinegars and the dunder, a small sediment formed, something like 200ml. I racked it off.

After fast heating up almost to cooking temp, I turned the hotplate off for 30min, but let the agitator on, perhaps it helps esterification.
The first distillate was strong and pleasant rummy, but of course also it had typical foreshots smells. And a chemical (menthol?) taste, probably higher alcohols. Later it became pleasant fruity (the typical tropical fruit sensation I like when drinking Rum), but a bit sharp and less etheral than the first distillate. Glue smell was only in the first distillate. At 65% more and more chocolate. (This time the molasses have a strong chocolate flavor, very different from other molasses I normally use.) The first hint of acidic taste I got was when the abv dropped under 60%abv. So I think I have esterified many of the acids and I am confident that I will get in the spirit run non acidic hearts without sacrificing aroma with an early tails cut. I think this is the way it will work: Getting many acids into the wash (by preventing them to evaporate during fermentation) and into the low wines (here the abv is too low for a high rate of esterification) by stripping way behind the 0% alcohol point. Then it needs two runs to turn them to esters or cut them with the tails. Arroyos concept with the fifth fraction with the rum oils after the tails won't work here at the spirit run, because a fifth fraction would be too acidic. But in general I think his concept works only with rectification at high abv. At low abv I think the rum oils are in the heads. Just like the fusel oils are in the heads at low abv potstill distillation and in the tails with high abv rectification.
I collected almost all alcohol (I stopped at 99.7°C). The taste at the end was burned chocolate and acid, but almost nothing musty (this is different than with a normal Rum. Perhaps the very clear wash after lowering the pH caused this.). I got 7.1l 46.7%. Very good flavor (a bit sharp of course, I didn't cut heads), but still too acidic. If at the spirit run I will have to cut the tails early because of acidity, I overdid the lime treatment. But at the moment I think, it's all fine.

Second middle run (worse low wines, much additives):
10.9l low wines at 20.5%abv. I added four days before distilling:
-200ml vinegar essence (20% acetic acid)
-200ml homemade molasses vinegar (unknown acid content)
-50ml homemade molasses vinegar, which has already turned to a butyric ferment
-200ml uninfected dunder
-750ml fresh molasses
Then I lowered the pH to 2.6. It needed 50ml sulphuric acid.
Because of the greater amount of additives, I got a thicker sediment (700ml), which I racked off.
All in all as I expected I got not the quality of the first middle run. Lack of rummy aromas. I collected in 0.5l glasses and stopped a bit earlier (4l total, 98.7°C). This huge addition of fresh molasses added a chocolate flavor a bit like speciality malts to it. Especially the last two liters have this. But those fractions won't manage into the spirit run I fear. This is what I have to think about now: What shall I use in the spirit run.

[distiller_dresden]

Hey der wo - I found this browsing around and thought I'd post and share with you specifically because it's from Hampden's home page, and also because it specifically mentions using "lime salts" in their process, as well as later discusses the GRLAA thing we were discussing some time ago about what it referred to-

Hampden Distillery is the only distillery in Jamaica that specializes exclusively in the making of Heavy Pot Still rums. It prides itself in the Art of making High Ester Rums from knowledge handed down from generation to generation using fermenters made more than a century ago. Although utilizing the latest technology and equipments to ensure product quality, Hampden’s Master Distiller and Wash Masters pride themselves in predicting the outcome of each production run making the process an art as much as a science. It is this, the long history, the retention of skills, the transference of knowledge through the generations, the preserving of tradition, the use of fermenters that allows for the right yeast interaction with the carefully blended wash materials and the unique processing of it’s Lime Salts that makes Hampden paramount in the High Ester universe of rums. Hampden do not use commercial yeast but cultures, suspends and regenerate its own. It is for this reason that Hampden is privileged with having the most loyal of customers that vote their approval via their orders decade after decade. We are proud that some of our current buyers can tell stories of their grandfathers not only buying rums from the distillery many years ago but also supplying equipment for the sugar factory and spending summers at the estate.



Hampden makes a variety of rums ranging from 50 to 1600 Esters. Orders are shipped in Liters Absolute Alcohol (LAA). The higher the ester range, the more intense the bouquet of the rum. Our rums are used extensively in the blending of other rums throughout the world. Our highest ester rums are prized by the food, flavoring and perfume industries. Currently, all rums are manufactured to order, however, Hampden does set aside certain Marks for aging.

I think that lime salts project was directly up the right alley - in fact you were visiting Hampden distillery. You probably knew that? I didn't though, and when I read it I thought of what a frickin' genius you are at rum. I still wish I could borrow you for a long month in the woods in a cabin with several barrels of molasses and panela and fresh water, a still, and some great yeast, where before hand we'd placed some dunder 6 months prior and it had grown legs and tentacles and began to attain consciousness. Then the magic would begin lol!

Oh, what is the infection that fruit flies carry and get dunder, please? I forget and a friend is asking.

[der wo]

No. I don't have read this before. Thanks. Fits well to the thread.
On the one hand it's nice to read it, perhaps it would have pushed me into the "salts thinking" a bit earlier. On the other hand it's just logical. If you add lime to acids, you get salts. The story, that you produce acids and those acids become esters ist a correct explanation, but it's a shortcut. And every high ester system (prolonged ferment or muck pit) uses lime to make the bacterias happy. So it's not a special Hamden thing. That lime has also the purpose to turn the acids to non volatile salts, is normally ommitted for simplicity I think.

Oh, what is the infection that fruit flies carry and get dunder, please? I forget and a friend is asking.

Aceobacter. Vinegar-bacteria. But it needs alcohol or the bacteria don't work. It can't make vinegar from sugar. But pobably flies also carry some yeasts for that part.

[distiller_dresden]

Thanks der wo! So the fruit flies probably introduce acetobacter and that works off the residual bits of alcohol in your dunder. If it's not carrying us too off topic, could you remind me again which infections are given from:
swiss cheese with holes -
potato/dirt -
yogurt - (lacto somethin?)
parmesan cheese - (read in a lab they got one of the bacterias when I was searching them on Google)

I use a bit of each of these in my dunder to introduce the proper infections and it's seemed to work wonderfully each time (I opt for a bit of potato over dirt). I use like 2 BB's size worth so I don't need to fish anything out later. Appreciate it, and this thread is great -- hell ALL your threads are great I've learned SO much from you about rum and it's deep deep DEEP rabbit hole.

[der wo]

I don't think dunder contains enough alcohol to get tasteable amounts of acetic acid and esters from it. Either they simply add vinegar to the wash or the fermentation is prolonged (and here the vinegar-bacterias produce it). Probably both. As long the vinegar is made from sugar cane (or molasses), adding it is 100% legal.

Yoghurt has a mixture of different lactic acid producing bacterias.
Cheese also (different ones of course).
Cheese with holes contains also propionic acid producing bacterias. This is why I would prefer using cheese with holes over cheese without holes or yoghurt.
Soil and potatoes contain butyric acid producing bacterias. Of course soil also contains much other things. But at the end at least at our conditions and with our methods for me up to now it was a garant for vomit smell, which is butyric acid normally.
One pit with soil, another with cheese with holes and then something for acetic acid (either small Rum wash turned to vinegar or simply adding vinegar to the wash or to the distillation) I think is the way to go for a good complex mixture.

[distiller_dresden]

Interesting! I thought I would sustain all the infections in one pit, in the past my pellicle was multi-colored and varied in texture and obviously comprised of different infections all 'working together' in harmony (?). It was like a kaleidoscope! The smell was sweet and sour/tropical like pineapple and chocolate -- it had hints of chocolate, fermented soy sauce, caramelized brown sugar or panela, pineapple or sour bananas, something creamy or custardy, raisins... I hadn't had it covered and it was in my laundry room, somehow fruit flies appeared from nowhere, we don't have them in the house, and they went nuts on it. So I did two batches of rum and got rid of that dunder because I couldn't abide fruit flies; they started being everywhere, we'd be watching TV and a damn fruit fly would buzz in front of your head.

But you advise different pits huh? I didn't know that.

[The Baker]

Chapter 4:
Middle runs

Perhaps here first a bit about triple runs: The idea is to get more flavor with a triple run than with a double run. Sounds strange? Here is why it's not: A double potstill run forces to finish the stripping early or the abv of the spirit run will be too low for a good quality enough clean new make. Stripping early reduces flavor. The hearts of the spirit run of a double run have to finished early or the tails will overwhelme the flavor. Finishing early reduces flavor. Of course hearts from a double run with 75%abv will have more flavor than hearts with 80%abv from a triple run. But what's with hearts with 70%abv from a triple run? This is the question. Three tails cuts vs two tails cuts. Three times cutting little (leaving little in the boiler) vs two times cutting much. Comparing double runs vs single runs (both with a reflux still) the double run wins always for me. So perhaps the triple run wins against the double run.

Because my low wines unfortunately are different quality, I decided to make one good and safe middle run with the good low wines (from 3 of 5 strips) and one experimental one with the worse ones. Only little additives to the good low wines and much to the worse ones. And perhaps I will do the spirit run only with the good high wines. Or perhaps I use only special fractions of the worse run at the spirit run too.

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Thanks for this, der wo. I am going to study it carefully, I think it will be helpful for pot stilling brandy from old wine, which I have a lot of.
The first jar I tried (out of some from blends of different but similar distillations) is insipid, no real brandy flavour.
I am about to sample it again after a week or so airing and the same time so far with two oak dominoes in the maybe 5 litre jar.
Thanks again.

Geoff