The Big Dunder Pit Thread

Smaug

Speaking of chocolate,,,,any chocolate notes at all?

FloridaCracker

Nope. Tried to smell chocolate but it just wasn't there.

Smaug

Bet it will be after distillation

FloridaCracker

Yippeee!! Yippeee! I hope so.

grim

Chocolate, interesting..

The Sweet Smell of Chocolate: Sweat, Cabbage and Beef

To figure out exactly which molecules contributed to chocolate aroma, Schieberle and colleagues had to pick apart chocolate aroma one molecule at a time. First, the researchers identified those volatile compounds that would react with human odor receptors and were present at high enough levels to register in the brain, which yielded 25 different molecules. These molecules included 2- and 3-methylbutanoic acids (both produce a sweaty, rancid odor), dimethyl trisulfide (cooked cabbage) and 2-ethyl-3,5-dimethylpyrazine (potato chips).

You guys will immediately notice 2 of those 3 compounds:

Dimethyl trisulfide (DMTS) - which is a common distillation sulfur byproduct.

Secondarily 2 and 3 methybutanoic acids are also known as 2 and 3 methyl butyric acid, which are short chain fatty acids that would be the result of our good friend C. Butyricum, or even Brett.

Guess that makes sense.

grim

Colonies forming on the surface and through the broth. This is the P. Shermanii.

grim

Hopefully you can excuse my very messy lab. After all, it's just dunder, no need to be too clean, you'd probably upset it.

punkin

What, no flow bench? :))

grim

Would take the fun out of it, the risk of botulism keeps me on my toes.

Kapea

@grim said: Hopefully you can excuse my very messy lab. After all, it's just dunder, no need to be too clean, you'd probably upset it.

You stole those stir plates from the Thomas Edison Museum!

grim

Stole is such a negative word, Tommy wasn't using them, and they weren't doing much good in the storage room, so maybe I did "appropriate" them. Tough these days to find a good stir plate that can spin a long bar in a 6 liter Erlenmeyer. When I say lab, it leans more towards the "meth lab" definition of lab, and not the sciency definition.

Kapea

The homebrew forums a et-up with folks makin' their own stir plates from computer fans.

Yours (Tommy's) are heated ones, no?

grim

One of them is a combo, convenient for boiling up starters and keeping cultures like this at temp higher than ambient.

Myles

@grim That's strike 1 grim :)) you will probably upset the management if you start discussing meth labs ;)

grim

Pretty sure the first strike was being excited about growing things that smell like body odor, vomit, and rotting milk.

Smaug

@grim said: Purty sure the first strike was being excited about growing things that smell like body odor, vomit, and rotting milk.

Naw. Just @punkin cuz he is skeer'd.

FloridaCracker

I am still looking for someone to give me their opinion on what my aged dunder tastes like. Punkin has not stepped up yet.

Kapea

Funny about that; all the weird food in China doesn't give him one second of pause, but dunder pits make him hide under the bed... ;)

punkin

Weird food won't kill me. Some of the bugs you guys are growing may. :-B

grim

I'd imagine the biggest contributor to flavor is going to be the cooked yeast and acids.

Acid forward with a bouquet of ripe cheese, full body of cooked cabbage, beef soup, and notes of boiled tomato. The finish is floral, with residual sweetness and burned sugar, and an estery finish on the nose. Reminiscent of a cross between 1963 Chateau Muscrat and Campbell's Tomato Soup, both stored in the trunk of your car for 20 years. Would be rated a 98 by Parker if not for the botulism.

FloridaCracker

@grim said: I'd imagine the biggest contributor to flavor is going to be the cooked yeast and acids.

Acid forward with a bouquet of ripe cheese, full body of cooked cabbage, beef soup, and notes of boiled tomato. The finish is floral, with residual sweetness and burned sugar, and an estery finish on the nose. Reminiscent of a cross between 1963 Chateau Muscrat and Campbell's Tomato Soup, both stored in the trunk of your car for 20 years. Would be rated a 98 by Parker if not for the botulism.

but isn't that how the best rums in the world are done? At least the Jamaican ones and they ARE damn good.

FloridaCracker

@punkin said: Weird food won't kill me. Some of the bugs you guys are growing may. :-B

The only way that you will build up a resistance is to start with small tastes of the dunder and then move up. Nobody said that you have to start with the chewable cheese cap. Start with the stuff in the middle

grim

Ok, so I pulled off a couple mL to test, I couldn't help myself. This wasn't the dunder, this was my molasses based culture medium.

pH down to 4.65 from 6.35 it started at, so a good sign that the bacteria are producing acids. Cloudy with sediment at the bottom, so something is going on. No fungal cultures at the top, but if there were it would have meant I did something wrong. Re-added the layer of argon and sealed it back up.

Smells are primarily molasses, yeast, some kind of sweaty stank odor but it's not significant, maybe a bit of flat beer. Not at all like vinegar, it actually a little bit fruity/floral at the end. Faintly gingerbread, something seems a little bit spicy, but that's just probably the molasses and the acids. Definitely some kind of unpleasant sweaty clothes smell to it though.

All in all though, it wasn't so bad. I'll let it keep going until the Clostridium takes it's place on the stir plate.

Kapea

@punkin said: Weird food won't kill me. Some of the bugs you guys are growing may. :-B

These look awful bug-like to me:

If I saw those crawling out of a dunder pit, I'd hide under the bed too! :-??

grim

Same deal, 4.65. Probably I hit a pH at which the bacteria slows, this would be in-line with the material posted above. Next time I run through I'll add a bit of calcium carbonate as a buffer to see if I can get additional growth before it hits the wall. Same odor as previous, maybe a little more floral/fruity, but sweat sock is prevalent.

Nice bacterial mat at the bottom, 1/8 to 1/4 thick.

I say success propagating P. Shermanii and producing Propionic Acid. This is not outside the reach of anyone that can do a yeast starter.

This would be ready to pitch into an active fermentation.

Myles

@grim are you intending to follow the basic principles of the Arroyo patent?

Start with a yeast fermentation then when you have achieved about 3.5% ABV, add the live bacterial culture to continue with a symbiotic fermentation?

There seems to be a mix of dunder uses out there. Some are adding it live to the fermentation, some are adding it into the boiler just prior to distillation, and probably a few others i haven't mentioned.

grim

That's the thought. Prep the two larger volume starters and add the both live cultures (C. Butyricum and P. Shermanii) to the active fermentation at some target ABV/Sugar/pH level.

If I were to attempt a second variation, it would be to ferment two larger starters and add those directly to a spirit run.

From an esterification perspective, I really wonder if the second approach should be superior. However, you would need to manufacture enough of the corresponding acids and esters in the starters, and I have no idea what the appropriate volumes would be. This would need considerable trial and error. (I'm not entirely sure if what's going on is a symbiotic fermentation to produce the esters, or if the esters are generated as a reactive component of the distillation, or maybe a combination of both).

To some extent, the first would still require some trial and error as well, but much less since Arroyo was nice enough to prescribe a 2% addition of starter cultures, with a range of approx. 1-4% total vol. I'd imagine the correct number is going to be highly dependent on the yield of the starter culture.

I'd still use fresh backset in combination.

Make no mistake, I'm not saying this is at all the right way or only way, just a way that seems interesting to me. I'm a little bit of a control freak, this approach has obvious appeal in that respect. Could very well be a complete waste of time.

FloridaCracker

Grim, I will be doing some trials of my own along side of what you are doing. I have about 30 gallons of "aged" dunder to work with. It has been brewing now for a little less than 3 months. The smell coming from the container is that of a stale bubblegum, if that makes any sense. The lid is on but it isn't air tight sealed so some smells escape and work their way through the garage. I also have 5 gallons of backset from my last rum wash that I kept in the fridge to use on my next wash. That wash will be 4th generation. I also saved the "sludge" from the bottom of the ferment tank to add to the next wash. About 1 gallon of that and it has to be packed with good stuff. That is also in the fridge. I am running a keg boiler right now with about 12 gallons usable space. My next trial will be with about 1 gallon of the aged stuff added to the boiler on the spirit run. Or maybe the stripping run?

I'm also toying with the idea of adding it to the boiler before the run and possibly giving it a little time to mix with the wash, say 4-12 hours. Don't know if that will make any difference or not but I keep good notes.

I am kinda in a holding pattern right now waiting to make a decision on a new still (Smaug). The wait is KILLING ME but out of my control. I will post pics of the new rig when I have it in my hands. I hate to do a bunch of trials just to switch stills right after.

grim

Bubblegum makes perfect sense - looking at the chart I posted, many of the propionate and butyrate esters associated with fusel alcohols/tails (1-Propanol, Isobutanol) are described as bubblegum.

FloridaCracker

That's good news. Hoping this doesn't go to shit before I can use it.