“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.