The Big Dunder Pit Thread

Eucyblues

@Pseudo - I need your help ....

It's bloody amazing how hard it is to produce stinking bacteria infested dunder !!

I've tried everything - even the Japbac doesn't stink

I prepared a 1L sample with Japbac (5 tabs of the 'strong' variety) and Lacto yoghurt starter - adjusted the pH, kept the sugar load to the correct level - it just gently fizzed away and smelt 'normal' - it's stopped now

Even old dunder with mould on it is drinkable (in sip amounts) and has no off smell

Back to the drawing board

jacksonbrown

What pH is your dunder?

Eucyblues

The stored dunder is untreated and acidic - about 4.5 or so - doesn't deter the mould but no bad smells

But I brought the 1L sample up to about 6.5 before adding the bacteria - still no go

jacksonbrown

"After the addition of the bacterial inoculum, greater care of temperature control is necessary, as it is then important that the temperature within the fermenter should not go much above 29 to 30 degrees C."

and...

"...while C. saccharobutyricum tolerates pH 4.7 to 7.0 with an optimum pH at 5.8 to 6.4"

Store some of your dunder around pH6 at 29° in a CO2 environment or a few days and see what happens.

Have a couple of reads though this (PDF) too, it might help.

Eucyblues

Thanks mate - I've read Arroyo quite a number of times - it is a good read although quite how the old rum makers manage to accidentally get this bacteria to survive in a rough old dunder pit is beyond me - mind you it is a dirt dweller and was isolated from feces so....ugh- don't go there..

I think the initial pH, sugar levels, and temp of the sample were fine

I think the lacto took over - I should have just tried the Miyarisan on its own

Something sure happened - the pH is down to 4.05 and it tastes as sour as @#$

maybe also not sufficiently anaerobic, and maybe the Clostridium tabs are relatively weak and I need to use more

I'll try again....

grim

You can find clostridium in human feces and propionibacterium is all over you if you sweat. They had it easy.

FloridaCracker

Can you get your hands on some fresh sugar cane? Not sure where in the world you are but that's what I used and somehow got the correct bugs. If you look at the very beginning of this thread you will see what I did. My live dunder is about 11 months old and has never been better.

Eucyblues

@FloridaCracker said: Can you get your hands on some fresh sugar cane? Not sure where in the world you are but that's what I used and somehow got the correct bugs. If you look at the very beginning of this thread you will see what I did. My live dunder is about 11 months old and has never been better.

I'm definitely in the right part of the world (in more ways then one) but a bit too far south to be practical ..I did try and harvest some from the side of the road once but I didn't have any cutters - I beat it to death and still couldn't get it out :))

I've prepared another 1L sample - boiled the dunder to get rid of extraneous bugs (stank some when boiled- skimmed scum off) , pH corrected to 6.2, 50gms sugar, 10 Myarisan tabs crushed - 10 hrs later - all quiet on the western front - I'm just too !@#$% hygenic :((

FloridaCracker

I also got mine from the side of the road. Sugar cane isn't cultivated here around me, I just found an odd clump that I have seen for years. Once I travel about 1 hour south, fields start popping up. Guess I got lucky and got the right bugs.

Word of caution: Punkin will tell you to RUN from the bugs! Don't listen. Florida Cracker says run TOWARD the bugs. They are your friends.

CothermanDistilling

I wonder if that same chemical is in the oil for my supercharger on my car... it has the stinky cheese smell, but I kind like stinky cheese, so I don't quite hate it...

Here is one quote from the automotive world: "BAD!! Holy cow I don't know what is in that stuff, but it made me want to roll around in used Anti-freeze and Gear oil just to get the sent off me."

Some say it is that the oil is animal(bacteria an animal?) based : The plant I worked in had hone oil that was animal fat based phew,they put in a de-scenter and it completely disappeared,sorry don't remember the product just that a couple of gallons treated 10,000."

And then someone hits it dead on: "No, it's a little different. It's a little like a mix of vomit, rotten goatmilk cheese, and the fermented dirty laundry from a hockey team. There's probably a butyric acid derivative in it."

Pseudo

@grim said: Butyric and Propionic are pretty different. Butyric is undeniable once you know it (pick up a tiny bottle of each on amazon or eBay) though. It's absolutely, undeniably, vomit. Propionic - if you close your eyes, it's aged cheese, parmesan, extra stinky, with overtones of BO.

Based on your description, I would say Propionic. Although my wife said "It kind of smells like vomit". It attached itself to everything I had on, socks, shoes, everything smells like it.

@grim said: Apple is usually acetaldehyde - but there are a couple of other esters that smell like apple (ethyl caproate, etc). The cranberry could be a bit of the acidic odor coming through on top of fruity. But, I believe benzaldehyde (almond/cherry) is part of the aroma of cranberry, and is a fermentation byproduct. Are you getting any almond in the distillate? That would be really interesting.

We stripped it, but haven't done a finish run on it, but I actually though cherry rather than the cranberry my wife was smelling - so interesting you say that. We'll likely do the finishing run on Friday, so will post back. We were pretty concerned/disappointed when the fermentation started to reek, but obviously pleased now that it's come around.

I spoke with the guys who harvested the yeast (local liquid yeast startup), they said it was harvested off a Russet apple in the area. The same yeast has been used for beer by a few of the bigger local breweries and no reported infections to their knowledge.

@grim said: Very cool, I hope you can replicate. You might want to harvest the yeast and bacteria again, and break it down into smaller samples and freeze it in a glycerine mix.

You fermenting open top?

It's in a 1600L walled conical fermenter, but there's a 2" ferrule up top that we left open, but plus the CIP pipe which was also left open. So I supposed you'd call that "open".

Right before the mash turned for the better, we pulled out two 25L buckets worth off the bottom of the fermenter and put in the fridge. But again, that was while it still smelled terrible.

There's still about 100L-150L we left in the bottom of the fermenter (mostly trub, I'd assume). The SG is at about 1.012 and it's been in there for about 9 days, so it's possible there's still a lot of live yeast in there.

So the question is (obviously pending the final run outcome):

1. Do we dump what's left, throw in some caustic cleaner and start fresh for the next batch with brand new yeast (which was our plan when it stunk to high hell)?
2. Do we dump what's left, clean it up, then create a new batch with new yeast, but add in those two stinky pails to infect it a few days before distilling (or two pails from the current better smelling trub)?
3. Leave what's in there (which is what we did last time to get to this point) and just add in a new mash on top, cycle it and see what happens?

grim

Just a quick note, I know sometimes the word "yeast" is used more generally to describe a more complex microbiology, but based on the smell, what you have going on is beyond yeast. I don't know whether the local yeast company just didn't do a good job isolating the culture, or you had a happy surprise from an inoculation perspective. If the latter, pitching on new yeast might not yield the same positive result, so I'd hold on to those buckets.

The big question to me is always can you repeat a previous positive result, which is the motive behind my obsession with the non-yeast microbes.

Pseudo

@grim said: I don't know whether the local yeast company just didn't do a good job isolating the culture, or you had a happy surprise from an inoculation perspective. If the latter, pitching on new yeast might not yield the same positive result, so I'd hold on to those buckets.

We had done a few fermentations with the same yeast before. We started by pitching enough for a 100L batch, then use the trub/lees to make a 400L batch, then used that to make a 1500L batch. All three of those were fine, no "cheese" smell. We left about 100L of trub/lees in the fermenter, added in fresh water/molasses up to 1500L again. That's when we got this recent fermentation.

So based on that, I'd deduce that it wasn't a yeast impurity.

I just put 150L of the low wines into the still. Some we distilled when the fermentation was still "stinky", some after that when it was fragrant. Let's see how it goes.

@grim said: The big question to me is always can you repeat a previous positive result, which is the motive behind my obsession with the non-yeast microbes.

Are we calling it "positive" then? Not 100% sure about that just yet, haha. But feel free to come pick up a sample of the infected yeast, you're welcome to it! :)

FloridaCracker

I've always been a little skeered to reuse trub from a live dunder influenced wash. Not sure why, it just seems like I am already pushing the envelope a little.

punkin

I've had that spew infection before on an all grain wash and understand very well when you talk about being able to smell it a mile off.

Pseudo

We ran 150L of it last night. The low wines were a mix of strip-distilled pre and post cheese-smell, so not sure if that was a factor. It smelled fine when we distilled it. Had a really, really short heads phase, which was interesting to note. The heads smelled amazing, but tasted just a bit off. The hearts were average size and smelled/tasted pretty average. I think I detected some of the cheese smell during the tails run out, but not certain since our shop still has a bit of that stench lingering (still got on my clothes and hands last night!!! Gross)

Checked on the trub/yeast that was put into the fridge while it still smelled (it had the WORST smell when we pulled it off the bottom of the fermenter. THE. WORST.) and even thought it was in a pail in the fridge for a week, it also turned and smells amazingly sweet and fruity now - which was unexpected since it was kept fridge temp.

We pulled off two more pails (4 total now) and will pitch those back into the fermenter with some molasses/water at around 1070 later this week.

punkin

I find it amazing that you would want to recreate that environment on purpose.

jacksonbrown

Punkin, have you ever read Kitchen Confidential? It's like 'feeding the bitch' to make the best bread in NY.

punkin

Jackson have you ever smelt this particular ferment these guys are talking about? I'm not talking about dunder pits in general, i am talking about working all day in the worse smell imaginable on purpose. I'd rather make just really good rum than really good rum with an extra hint of deliciousness if it meant i didn't have to have that reek lingering on me all day and all night.

FloridaCracker

Well done Pseudo. Glad to see that me and Grim aren't the only ones willing to venture into the murk. I am and always will be convinced that the difference between an average rum (what I first made) and a really nice one HAS to be the bugs. Or successive generations. Or both. Who knows.

So far in my trials, the only time that I produced a product that I absolutely didn't like was when I added some of the live dunder to some low wines right before the run. Just a little too much funk smell and taste for my tastes. Even after aging it was a taste that just wouldn't go away. Ended up dumping the last liter or so down the drain.

Pseudo

@punkin said: Jackson have you ever smelt this particular ferment these guys are talking about? I'm not talking about dunder pits in general, i am talking about working all day in the worse smell imaginable on purpose.

It's actually not working in the smell that bothers me - you acclimate quickly. It's the smell after you leave. It sticks to your hands, hair, clothes, and doesn't go away. I've washed my hands 100 times today and I can't shake it. We're going to do one more, then decide how worth it it really is. My mistake with yesterday's run was adding in feints from a previous run that I suspected had an off flavour. So now I feel like I want to do one clean run of it all the way through, starting when it goes sweet.

@FloridaCracker worth it. If you're not willing to get dirty, then it's not worth playing, right? We're not open to the public, so no harm. I'll do one more, then decide. Just hoping my landlord doesn't kick us out of the unit!

Kill_Devil_Spirit_Co

I guess thats a plus. I'd hate to subject my clientele to such things when theyre trying to sample a gin haha

FloridaCracker

Ended up with about 7.75 gallons of 60 abv after cutting from my gen 9 & 10. Once again I tossed all heads and pretty much shut it down as soon as tails started. What I ended up with was a totally drinkable, very flavorful rum. Into the "new" 5 gallon barrel that ended up being 6.25 gallons.

grim

Yeah the Barrel Mill 10s usually clock in a bit over 11.

grim

Regarding smell - you can get a 55 gallon carbon adsorption drum pretty easily.

Vent your fermenters through the drum - you'll smell fresh as daisies.

These were pretty cheap: General Air Pollution Control Barrels

Not everyone cares for the odor of fermentation.

Smaug

One of the recommendations back on HD a while back was to install some mouth wash into your air locks rather than water.

The thing is, fermentation smell gives good sensory feedback that can be valuable.

grim

Stillage is awful in comparison

Unsensibel

Stillage sucks. Ferment delicious. Malted oats fermenting smells like cinnamon breakfast

punkin

It was the rum ferments that broke the camels back and had her insist i built my brewery before the rest of the projects and get the fermenters out of her laundry. =D>

I thought they smelt nice, but i think cattle floats smell nice too. ~:>

RobertS

Thanks to this thread, I'm starting and planning experiments for improving our rum at Griffin Claw. Pulled a 55 gallon drum of stillage for a dunder pit, but given that it's still winter in Michigan, I don't have high hopes for that going well. Best case, it doesn't do much before summer and then I can let it go. It'll be several months before the next rum batch, but I'm looking forward to following grim's methods and taking advantage of having an in-house lab to dial in pitch-rates. Hopefully I'll be able to throw out approximate target volumes for people who can't do cell counts, er... 'in-house'. Been taking notes and would be happy to add any trails to my rum experimenting people want to see done.