“Synthetic” dunder.

[Al The Chemist]

Interesting. Appreciate the info. For me, it would be mostly for single runs. I might get by with one. Would you think it be functional to load the acids into the thumper instead of the boiler? This would resolve the dunder issue. 

I might start pursuing a vertical thumper again.  

[Bolverk]

Yes acids in the thumper. If you really want to get serious save your thumper juice (lees) and calcify the acids with lime, dehydrate them and add them back to the thumper (you need to reacify them before hand)

For a single thumper, the proportions that i found work the best are a 1.5 in the boiler (higher abv coming over to the thumper emulates what would be coming out of the first retort (less water)). Heads and low tails go in the boiler on the 1.5 run.

1/10 the volume in litres of the ferment, so 10g ferment = 1L in the thumper. 10% of the thumper charge is carboxylic acids (the other 90% is high heads at about 50% abv), then add about 20% of the acid charge in sulfuric.

 

So on say a 100g fermemt I'd strip half, add those 10g low wines to my remaining 50g wash with any feints.

24 hours in advance in a separate glass container add 9l of high tails and 1l acids (900ml aceditc, 30ml butyric, 30ml lactic, 15ml propionic, and 15ml caprylic acid) and then do about 20ml of 98% sulfuric (add the first 10ml, then sneak up the the remaining amount until you start to smell the esterification). Let that sit over night then add it to the thumper when you're ready to do the run.

[Al The Chemist]

Excellent info. Thank you.

Can you explain more to what you mean about the "1.5"? Is that ABV of tumper as it related to the boiler? 

 

A 1 gallon thumper is very manageable for a smaller dedicated still. At that size even 2 should stack pretty well. I've heard some conversation discussing the thumper being 50% of boiler. Seems excessive. 

[Bolverk]

A "1.5" run is when you strip a portion of your beer and add that back to new beer and run that as a spirt run. Ie: For a 10g ferment, you strip 5g down to about 1g of low wines, then on your next run, you'd add 5g of the remaining beer and the 1g of low wines.

1/2 can be excessive but it depends on your initial charge and alcohol percentage. Really, a more accurate way should be your AA x 5 + whatever your initial thumper charge is. So in 10g 8% charge that's .8g AA, x 5 gets you 4g, plus your thumper charge, say 1 gallon, that's gets you to a 5g thumper.

Here's Haggys thumper calculator from HD, you can play with all kinds of scenarios.

https://homedistiller.org/wiki/htm/calcs/calcs_haggy_pot_plus_thumper.html

[Al The Chemist]

Awesome, thanks!

[Al The Chemist]

Tested my cuts. Conclusions.

 

Does a “synthetic dunder” (IE: deep tails + Backset + controlled acids) work? Yes, 100% it does.

The next experiment will likely be a vertical thumper setup, as the distillation method seems to be the obvious next issue.

Heads:

-          Really nice, strong tropical fruit, coconut and pineapple, nice and fresh high notes on both the nose and pallet. Though far too headsy to blend.

Hearts:

-          Almost clean and neutral. A bare hint of pineapple, though (in my taste) not enough to distinguish it between a vodka and a Caribbean rum.  Maybe more reminiscent of a cachaça.

Early tails:

-          Really nice deep funky aromas, molasses and moldy cheese but has that tailsy “burnt iron” finish. Wondering if cask aging will remedy that over time.

Deep tails:

-          Explosive foot fungus and heavy cream, way to tailsy to consider blending. (went into dunder)

 

Would have loved to get the heads and tails esters appear in the hearts. Considering the evaporation temperature of these esters and the distillation method used, I guess this is not surprising.

[Bolverk]

Nice!

Those clean neutral hearts are probably from the panela. Panela makes a really clean (boring imo) rum... You won't get the Jamaican style funk without a fair amount of dunder (stillage) and at least some molasses. Some old recipes I've seen say as much as 40% dunder, 10% molasses, and 30% skimmings. I followed these percentages with excellent results the only difference is that since I don't live in cane country I used panela in place of skimmings.

A vertical thumper will work, but I still think you'll end up with a lot of your esters in your heads, but you should have a bit more in your hearts.

Your funky tails... As you found earlier you used too much butyric. Easy fix for next time.

Can't really say on the barreling... my goal was always something more akin to Hampden rumfire. Barrels can clean up a lot, just don't know how much.

Yeah all those heady esters are why I bypass the fore/heads before installing vapor in the thumper. Using those valves will let you put those esters where you want them instead of in the high heads.

[Al The Chemist]

A bypass valve above and below the thumper is part of the planned design. I'll see what I can pull off.

[Kindred Spirits]

I have always been interested rum and also in "non-standard" still designs, and rum is one of the perfect examples of a spirit that benefits from the extras like, double retorts and thumper setups. 

One of the issues that I always run into when designing a distillery for clients is the amount of floor space required for double retort setups. I haven't personally seen a vertical version of a double retort setup but I imagine that would be really cool to see. Has anyone seen anything like this?

 

[Bolverk]

Never seen one in person.

The closest thing I can think of is the early 3 chamber designs before they added the preheater chamber at the top.

 

[Al The Chemist]

@Kindred Spirits, I'm looking into commissioning a single vertical thumper for a small scale test. I am worried about the stability of a double retort stack on a small scale. Curious what you guys think about a plate, then thumper? So essentially a plate to strip and a thumper to redistill and infuse. Footprint is exactly the issue I'm trying to resolve. 

[Bolverk]

I think a plate below the thumper is going to keep all the good stuff you want from carrying over into the thumper.

If you're worried about too low of a proof id put the plate on the output... the Forsyth at Worthy Park has plates on the output of their final retort.

[Kindred Spirits]

8 hours ago, Al The Chemist said:

@Kindred Spirits, I'm looking into commissioning a single vertical thumper for a small scale test. I am worried about the stability of a double retort stack on a small scale. Curious what you guys think about a plate, then thumper? So essentially a plate to strip and a thumper to redistill and infuse. Footprint is exactly the issue I'm trying to resolve. 

What's cool about the manufacturer I work with is can fully customize the stills I get for clients. I draw up the design on CAD, their engineers verify fabrication plans and then they build it up. Its been great to be able to hot rod stills with larger heating ports for better heat up times, different shaped helmets, and have more flexibility in connection types.

[Kena1979]

Hello @Bolverk, @Al The Chemist 

I am planning on distilling a 1.100 liter volume twice over column (max 7 plates) as we don't have thumpers.

I was told by professionals that you should not use too much acid mix per liter, they suggest 0,2 tot 0,8 ml per liter, and even downscaling that for higher volumes per 100l.
With this in mind I would use 0,5ml acid mix per liter, as I used 0,2ml once and the impact was there but not enough.

What would you suggest to be the best option from your point of view and experiments?

• Adding 500ml acid mix to the 1.100 liter on strip run over column
• Adding 99ml acid mix to the 200 liter spirit run over column
• Do both

Thanks!

[Bolverk]

Sorry Kena, I don't know,  my experience is using it in more of a cousins prosses with retorts.  I've never had good results getting it to shine through when using a plated column.

[Al The Chemist]

Hi @Kena1979

I’d like to get some clarity on your process before I can help. Sorry if I’m being dense.

Is this 1.1 liter your wash?

Are you planning to double distill this wash using 7 plates in your column?

[Kena1979]

@Al The Chemist, no problem at all!

It's a 1100 liter wash at +/- 8.5 ABV, which will be distilled over column twice

Volume for Spirit run probably will come out at max 200 liter at 50%

STRIP RUN > We will need to see if all 7 plates will be needed, we can disable them seperately (see image) > aiming for 70% min, 80% max
SPIRIT RUN > Will probably be limited to 4 plates, smaller installation > aiming for 89% max

Where/How do you think  the acid mix will have the most effect in this set-up?

[Bolverk]

Kana, do you have a way to bypass the plates? Per design the plates are meant to help you fraction out as much etoh as possible, and thats a good thing in some products but in rum that is going to make it very one dimensional (compared to rum made in double pot or double retort) .

When you start playing with the carboxylic acids you really want more alcohol diversity. Ethyl butyrate (also known as ethyl butanoate) is going to be this generic kinda fruitiness, the good stuff is going to be isobutyl butyrate which is going to be fruity and pineapple (in the right concentrations). You want that alcohol diversity to get the best esters, this is the reason high ester rum is made with a double retort. For instance when manufacturers are setting up with a double retort they are front loading high tails and low tails in the retorts to get a higher concentration of diverse heavier alcohols to push those acids through to get those "better" long chain fatty acid esters.

Additionally the boiling point of butyric acid is really high (350-380f or something like that), it's only going to come over from the pot when bonded with something else that lowers it's BP, pushing it through plates is going to strip out those heavier molecules and it's never going to pass. You might be able to get some to come over through 1 or 2 plates, id venture virtually nothing through 7.

On top of that you need to acidify the environment to with a mineral acid like sulfuric to act as a catalyst for esterification. By putting in it a pot of beer or low wines your going to have to add a ton of your carboxylic and mineral acid to get just the faintest traces of it to come over. Where as in a double retort the last retort full of high wines (high tails) is going to be 10% of the beer charge, carboxylic acids would be 10% of the retort charge (butyric acid would be about 3% of that 10%), and the sulfuric would be about 20% of that 10%.

So just for round numbers:
Beer charge is 100l
First retort is 10l
Second retort is 10l total volume
In the second retort
9l high tails
1l total carboxylic acids
93ml aceditc acid
3ml butyric acid
4ml other acids like propionic, etc...
Then 200ml of sulfuric acid is added to the high tails and carboxylic acid mix and is let to esterify for 24 hours before making the run.

All that to say, a plated column is just the wrong tool for the job.

[Kena1979]

@Bolverk I know the column installation is used for Spanish (light) style, not English (heavy body), but still, also in Spanish style, acid mix is used to adjust aroma in some way. We can disable the plates 1 by 1 to do potstill if needed.

I am aiming for a light rum though, with subtle fruity esters; for what I read and tested myself my best guess is that the acid mix is added to the spirit run and let is esterify with sulphuric before running, if you're aiming for this type of rum with this type of installation.

But of course this can be wrong. 

[Silk City Distillers]

Going to blow your minds...

Dipped into two test barrels last week. These were funkier Jamaican style molasses based rums.

First test barrel - normal batch (1 week Ferm), proportional share of heads added back into the barrel.  Yes, we added the entire heads back to the barrel as if no heads cut was taken at all.

Second test barrel - this was a longer fermentation (3 weeks Ferm), 5 barrels worth of rum in this batch, the entire heads cut from this volume of rum was added back to 1 of the 5 barrels. I underfilled to leave room to add back the heads cut. The net was far higher proof than the other barrels. I did this on a whim when I was setting up to barrel. I thought that the first test batch barrel was aging out in an interesting way, so why don't I amp it up far beyond that. Not only not taking a heads cut, but adding back and essentially completely concentrating the heads volume unnaturally by 5x. Now, our heads cuts on this style are never nasty, in fact I love opening the feints tank for a smell.

Both barrels are fantastic, and exhibit characteristics that I've been missing from our rums.   Dark rum, even with heavy dunder and bacterial fermentation, were closer, but still far away.

Only about 6 months in a 30g ex-bourbon at this point, so still very young, but f*ck me the 5x concentrated heads is fantastic. Based on what I'm tasting right now, this will undoubtedly be the best barrel of Jamaican style dark rum we've ever made.  Side by side with any of the 4 other barrels, is far superior.

Take it however you want, but I'm going to strongly suggest that for many high ester rum styles, this is unequivocal proof to me that there is no heads cut taken.  I've been behind the scenes in some notable Caribbean distilleries, and I long suspected this was the case.  I have a few high ester samples from a reputable broker, and there is far more in terms of similarity than I would have expected.

[Bolverk]

 

@Kena1979

I gotcha, so your goal isn't a heavy heavy rum. In that case yeah, I have no clue how much to add. Its going to be a lot just to get a small influence. In 200l of low wines id guess it going to be an the neighborhood of 1000ml of butyric and 200ml sulfuric. 

I'd run your low wines off however you normally do, then pull out enough to run a small test batch and add the butyric and sulfuric and run that in a basic pot stil configuration and adjust the amounts to taste, then extrapolate up to full size. 

[Bolverk]

@Silk City Distillers I'd definitely like to try this when it's ready

[Silk City Distillers]

On the butyric, this is an important piece:

http://www.bostonapothecary.com/wp-content/uploads/2016/02/possibilities-of-utilization-of-butyric-acid-for-rum-making.pdf

You can work backwards to understand concentrations, also ph, etc.

 

[Brewstilla]

Silk - I'm going to throw some 100% heads in a 15 gal used bourbon barrel just to take this idea to the extreme and see what comes of it. Recommendation on barreling proof?

[Al The Chemist]

@Silk City Distillers Would love to get my hands on one of those bottles. It makes perfect sense.  The heads contain a high amount of ethyl acetate, which has a nice sweet and heavy aroma. Its boiling point is so low that it’s usually gone by the hearts. I also don’t cut the heads, though I’ve never tried concentrating them. Any toxicity concerns?