The Big Dunder Pit Thread

grim

Only recommendation I can make on keeping the bacteria alive in dunder is to keep your dunder closer to a wash than just straight backset/stillage. Perhaps when you make a batch, replace what you take as dunder with fresh unfermented wash. The bacteria will stall out based on pH.

The odor of these two bacteria are unmistakable. Butyric - Vomit and very heavy aged parmesan cheese. Propionic - sweat socks, body odor, with a sharp vinegar finish.

grim

Or just leave a stick of butter out for a few days, and add that to the wash.

Those old scots and potstillers that used butter as antifoam might have been on to something. At a typical 3-5% butyric acid before going rancid, chances are years back the butter had probably gotten significantly more rancid before it was used in the pot still (pasteurization, etc). I'd eat the good stuff, still the bad stuff personally, so it's plausible that their butter butyric acid content could have been significantly higher.

This would have added a whole host of butyric acid esters and the acid to the distillate.

Eucyblues

@grim said: I'm writing up a patent now that includes high power pumped IR lasers to induce these same chemical reactions through lowered activation energies. :)

OMG X_X What a hobby.. =D>

grim

I'm doing some other stuff on medium chain triglycerides too. I'll post that when I can write it all up.

grim

Volatile Fatty Acids in Some Brands of Whisky, Cognac and Rum by Nykanen, Puputi, and Suomalainen (Journal of Food Science, 1968) - has one of the best overviews on the topic.

grim

Eucyblues

@grim said: Even the new patent, the one that includes 420nm light (actinic, fish bulb lights, bug zapper lights, disco black lights) is absolutely doable on the hobby side.

He covers almost everything bar the kitchen sink - 420nm to 1000nm - the visible light spectrum and into infra-red - I've been 'reacting' my stuff every day

grim

How is that even defensible in a patent? Hogwash, you can't patent the whole field of photochemistry.

Or do we believe the green bottle whiskey makers?

FloridaCracker

@grim said: Only recommendation I can make on keeping the bacteria alive in dunder is to keep your dunder closer to a wash than just straight backset/stillage.

What is the thought behind that? My dunder is now 9 months old and shows no sign of going bad (he says with fingers crossed). Maybe you are referring to the dunder made with bacteria not aged backset.

The more that we see here from various research really confirms the long reflux called for in Arroyo. I'm convinced that it really brings out the good shit in the wash. With full disclosure, I only reflux for 1 hour which is on the short side of the 1-2 hour recommendation but I really take the fores/heads very slowly which I think brings it closer to the 2 hour mark.

Another finding from my trials is that too much funky smell/taste comes over from a single run which is called for in Arroyo. I do a stripping run which also brings up more questions. Have I, during the stripping run, gotten rid of some good shit that should be heavily refluxed? I have not tried to do a 1 1/2 run. I am REALLY liking the stuff that has been coming out of the barrel from my latest rum runs so I am hesitant to go back to more trials. Not what I would consider to be a "heavy" rum but not light either.

Not a bad place to be.

grim

My lab still trials use 1 hour reflux periods, which is more than enough to create esters out of nothing but the alcohol and the acid. It works even with a larger percentage of water than I thought would be possible. I used to think that this would be an "on-the-plate" phenomenon, but in a low wines distillation, there would be esterification going on in the still boiler in addition to the plates. The yield is lower, but I'm not sure that's really a problem, too many esters and you end up with something closer to solventy bubble gum.

The big difference is with the single run, you might be passing through more of the volatile acids, non-esterified, which are going to give you more funk. On the two pass, the spirit run is going to have significantly more ethanol to water, which is going to favor esters over acids. What's the general smell of the distillate in your two pass - is it a kind of light, fruity, ethereal smell?

My next set of trials are going to be tails distillations with the acids.

FloridaCracker

@grim said: What's the general smell of the distillate in your two pass - is it a kind of light, fruity, ethereal smell?

Exactly.

grim

My protocol is to collect four total samples, 3 fractions and the final sample being the remaining contents of the still. The size of the 4 samples is equal to the total volume.

This doesn't really mimic a true heads/hearts/tails scheme, because I'm using pure alcohols and water.

However, generally, the first two fractions contain higher proportions of the ester. I think that the second fraction has a stronger odor/flavor, but that may simply be due to the second fraction going about 30 minutes longer than the first fraction.

Now, the final fraction, that seems to carry over more of the acid. It starts as a kind of brightness, but moves into a kind of pungency, into finally being very characteristic of the acid. Funk for sure, especially with acids like butyric.

The remaining still contents always smell strongly of the underlying acid, sharp, pungent.

CothermanDistilling

"LASER"... sharks with LASERS!

https://www.youtube.com/watch?v=Bh7bYNAHXxw

Clickeral

Set her up for a rum run 4plates been too long since I had her going need to get some more gear and make some gin

Kill_Devil_Spirit_Co

The stainless/brass combo is oddly satisfying against the brown brick/white grout @Clickeral, nice stuff. My buddy runs a 4" by 4 and has very nice results

Clickeral

@Kill_Devil_Spirit_Co said: The stainless/brass combo is oddly satisfying against the brown brick/white grout Clickeral, nice stuff. My buddy runs a 4" by 4 and has very nice results

Yeah I can run upto 6 of the procaps and I have a packed section (sitting next to it in the pic)

Ive also got 4 normal plates which I can use when I get more tees haha.

Only have 4800w to throw at it and need to build a new power controller so its running slow. However a vodka run (I do two) is 6 plates packed section and 4800w with full reflux. God she goes quick 4.5l ish an hour

punkin

Looks the business mate.

Eucyblues

Received my JapBac the other day - have to mess about with my dunder now - take a sample - raise the pH to about 6-6.5 - add some sugar and crushed bac tabs and see what happens...

PS - my 'cooked' rum is now very nice - a dose of barrel strength + four ice cubes - Yum

The cooking has (subjectively) appreciably accelerated the aging.

FloridaCracker

Here's the 11 month update on the original dunder pit that started this thread.

She's alive and well, thank you. Just took about 3 gallons to add to my latest generation of rum wash, Gen 10. The smell hasn't changed in the last 6 months or so. The predominant smell now is bubblegum with a hint of funk. Color is still about like a mocha coffee. I didn't open it up to look at the cap because I know that I still have about 35 gallons left.

Now that my rums have had a little time on them, I can really appreciate more complexity coming on. My Gen 8 is almost gone after giving out a bunch of Christmas presents and that is sad because it was really good. I'm keeping one liter of it in archives to be opened at a later date. I've done that with most generations so that one day I can go back and compare.

Since I am running low, I checked on the 6-7 gallons that I've had in a barrel for the last 3 months (gen 9). Took one liter out to inspect and it is already better than Gen 8. Color is beautiful and the overall smells are butterscotch and caramel. Zero oak smell or flavor. This is the third use of this barrel and I'm loving the results. First use was for rye whiskey and the last two for rum. I'm going to leave the rum in it because I don't think that it will overoak anytime soon. Maybe I should pull half and leave the other half just to be safe. I will be running Gen 10 in the next month and it will either go in this barrel or a 5 gallon one that I got a couple of months ago.

On a side note, I finally got a refractometer to check my washes and that has been very eye-opening. From what I have gathered, the brix number should be below 20 for a rum wash but mine came out to 23. I'm using 100% molasses that came directly from a refinery so there is nothing in it but molasses. After just 2 days of fermenting, the brix has dropped to 14 and the ferment has really slowed to almost nothing. SG was 1.096 and is now down to about 1.03. From my calculations that gives me an ABV of about 9% which is perfect.

These rum trials over the last year have been a blast and I hope they get better and better. Age surely won't hurt them. Another thing that I have consistently read is that rum needs to be off of oak for at least 6 months and one year is better. I don't know if my US treatments have helped speed things up or not but 3 months is about all it is taking to make it drinkable. It also could be that I make VERY tight cuts. One curious note is that I absolutely toss all heads and keep limited tails. The butterscotch smell I always thought was associated with the heads. Maybe not so.

What I really need to do is get a bottle of this to Smaug and get his opinion. I am more than just a little biased but I have pretty much given up whiskey over the last 6 months because the rum has become my go to spirit. The only unbiased opinion that I have gotten was from a friend who is Jamaican and loves Appleton. On our recent yearly guy trip I let him try my rum and he drank it exclusively for the entire weekend. He now wants a steady supply. LOL

Sorry this has been longwinded but I hope that this thread will help those who want to venture to the darkside. Who knows? Maybe even Punkin will embrace the funk.

punkin

Not fucking likely.

I'm glad you are living to tell the tale though.

jacksonbrown

Good to hear.
All my gear is locked up at the moment but I can't wait to get it going again.

@FloridaCracker said: On a side note, I finally got a refractometer to check my washes and that has been very eye-opening. From what I have gathered, the brix number should be below 20 for a rum wash but mine came out to 23. I'm using 100% molasses that came directly from a refinery so there is nothing in it but molasses. After just 2 days of fermenting, the brix has dropped to 14 and the ferment has really slowed to almost nothing. SG was 1.096 and is now down to about 1.03. From my calculations that gives me an ABV of about 9% which is perfect.

It sounds like you have it sorted but I was having issues with my refractometer too. I posted a Q up here and got some great answers form crozdog, it wasn't as simple has just taking two readings. The FG needs some extra calcs and the molasses has lots of other minerals and stuff dissolved in it and with the dunder method that will also accumulate too.

FloridaCracker

@jacksonbrown said: Good to hear.
All my gear is locked up at the moment but I can't wait to get it going again.

It sounds like you have it sorted but I was having issues with my refractometer too. I posted a Q up here and got some great answers form crozdog, it wasn't as simple has just taking two readings. The FG needs some extra calcs and the molasses has lots of other minerals and stuff dissolved in it and with the dunder method that will also accumulate too.

Sure will be nice to hear how about your progress or anybody else's. Feel like I'm all alone out here. LOL

I'm not sure that I have it all sorted out. I feel like there is still some unfermented sugar in my washes even though I can't taste it. I keep an eye on pH, temp and the gravity but I'm sure there is room for improvement. I might cut down on the amount of molasses per wash. Right now I am using 8 gallons for a 40 gallon wash.

jacksonbrown

So your using about 20% molasses?
I'm was using about 10 litres and topping up to 50 litres so about the same.
After a day or two I was topping up with dunder to just under 60 liters.

There's no way to crop yeast once you introducing an infection is there?
I might have a go and see what it does to the yield. At a guess I'm thinking that adding old sludge to a fresh, oxygen rich wort will be a disaster but who knows.

grim

i wouldn't reuse the yeast from a rum ferment you've spiked with bacteria, dunder or culture, as the bacterial load will be very high.

However, if you ran a clean white rum ferment, that would be prime to recycle into another white or a dark. Maybe a back to back workflow.

grim

Awesome commentary @FloridaCracker

jacksonbrown

@grim said: i wouldn't reuse the yeast from a rum ferment you've spiked with bacteria, dunder or culture, as the bacterial load will be very high.

That's what I'm thinking as well but I'm still a bit curious to see what the result would be.
Given that the aim is an anaerobic environment but ferments start off aerobic I'm predicting some very bad smells. I kinda want to trial a reduced density wort too.

punkin

I was pitching mollasses on the lees of ferments but found with the feed grade mollasses i used the second gen would be slow as all get out and the third would stick. You may have more luck if you are top cropping or something but i figured the preservatives were building up in the yeast bed.

grim

Molasses that uses propionic acid as a preservative sounds like it would make a fantastic rum as the propionate esters would be very high.

Skips the need to use propionibacterium to create it.

grim

Ethyl propionate - juicy fruit bubble gum pineapple

Isobutyl propionate - rummy, fruity, sweet, tropical

Two of the principal rum esters.

jacksonbrown

Punkin, were you sterilising first? i.e. boiling the wort?
You might have had a super high bac count and not even realised.
I know the feed grade stuff I used to use would introduce all sorts of unintended stuff.