The Big Dunder Pit Thread

FloridaCracker

First impressions of what you collected? I have been typically keeping the still in full reflux for an hour and then a fairly slow collection of fores/heads so about 2 hours before hearts start. Last 2 or 3 runs have produced hearts that are drinkable (after proofing) off the still. After about 2-3 days of airing and then an US treatment, I have some even better stuff.

To capture more complexity, I have really been trying to find some tails to add back. There seems to be, on average, 2 jars in the tails that I feel like add to the mix without adding off flavors. These 2 will be spread out amongst the 6 or 7 jars of tails that I collect. The funny thing is, it is NEVER the first jar of tails. Once I detect tails they get nasty quickly then change. According to everything that I have read, that is pretty consistent with what to expect.

One of these days when I am adventurous, I will collect by volume like the patent. Bet I've read through it a dozen times over the last few months and feel like I am taking the best parts of it and adapting them to my equipment but there is always room for improvement.

BTW, great work on the new parrot.

jacksonbrown

Well there were some very, very interesting smells going on.
I also dropped in about 50g of cultured butter in at the start too to help with foaming and I didn't have to touch the kill switch once. 100% power the whole way and no foaming at all.
I am also using food grade molasses this time and a different dunder strain and yeast but all in all... promising.
I still need to do the final blend tomorrow but considering it was a single run with a ripping take off speed it actually seems OK. I let you know in a year :D
I'm going to do Punkins No-Chill cubes for my backset. To make some space in the freezer.

jacksonbrown

So I wouldn’t recommend what I did last time.
From 12kg molasses (55’ish Lt wash) I only got a few litres of 65 % but a lot of waste (tails).
I think the 0%RR pot mode I used was a bit too much on a single run.
Nothing lost though as it ended up just being a stripping run (and that’s what it smelled like too).

Next try I’ll do the same thing but set the RR% meter to 50%. I think if I tune the right RR to the wash recipe it'll get a lot more consistent.

There really wasn’t enough definition between the sample jars in the first run. They all had a bit of arse in them from jar 3 to jar 10. It was really just a rough strip.

I'll keep tweaking it though, I like the concept.

FloridaCracker

There are SO many varitions with this rum/dunder thing and just one change makes a huge difference. I'm drinking from my Gen III stuff done back in June and it is the least favorite of any that I have done. The highlights of that generation were that I added live dunder to low wines and ran it. Too much funky flavor for my liking. Punkin would not be a fan.

CothermanDistilling

@FloridaCracker said: There are SO many varitions with this rum/dunder thing and just one change makes a huge difference. I'm drinking from my Gen III stuff done back in June and it is the least favorite of any that I have done. The highlights of that generation were that I added live dunder to low wines and ran it. Too much funky flavor for my liking. Punkin would not be a fan.

tidbits like that are what make this forum awesome... thanks!!!

Smaug

If it's too twangy, just add it back and run it again.

grim

@Jon_o - any update on your run?

Jon_o

Here an update.

Here is what I found from the capsule dosing. I tried to put to a table format.

I think the capsules are doing something with the yeast, but I think the dosage needs to be around 200 capsules or higher (per 5 gallon wash). These were added same time as yeast.

For the effect of the final product, I can not make any judgements as of right now. I am trying so many things, and I can't isolate it right now.

I tried to do a "tradition rum style" distill with double thumpers with heads and tales. They have rested for a week and I can see the oil film on some of the jars.

This is want you want from this style of distill correct? Some smearing of heads and tales to carry over the flavor, correct?

My base spirit that I put in the thumpers, was not of the greatest quality and my final output reflected that. I guess garbage in, and garbage out.

So I'm running another all molasses stripping run right now, so I will try to use this to fill the thumpers for the next runs.

Jon_o

I forgot to add, 1 gallon of backset or dunder for each run to the table.

FloridaCracker

@Smaug said: If it's too twangy, just add it back and run it again.

I did that with about half of that generation. That stuff was before I got my barrel so I used the dominos. I don't think the barrel would have made any difference. That "twang" just isn't going away. Since I have almost emptied my barrel into jars for final aging, I am working on filling it back up. Actually I will probably just fill it halfway since I am accumulating quite a bit of rum of various generations. I have already stripped most of Gen 10 and will probably do a spirit run sometime this week.

While I was doing some stripping I added some of the backset to my dunder barrel and now it has about 40 gallons. Won't have to add any for a long time. Just hope it doesn't shit the bed now that it is gaining maturity.

vooharmy

@Jon_o said: I think the capsules are doing something with the yeast, but I think the dosage needs to be around 200 capsules or higher (per 5 gallon wash). These were added same time as yeast.

My experiment yielded similar results ie Using the tablets to make a culture may be the best way forward. Alternatively I considering cubing backset and dosing it a week prior to pitching the ferment and going from there.

jacksonbrown

So wife came home and said the house reeks of vomit. Does that mean I’m winning?

I had a 60Lt fermenter and I did half yesterday and the other half today.
I did the same cuts on ABV as last week but I tried to tune the RR this time rather than ripping pot mode.

Yesterday I was around 50%RR for the whole run and today I tried to keep it around 75%RR.

It started off smelling a lot like cheese, very lactic. The 50%-37.5%ABV tails cut had a bit of burnt rubber smell to it.
Below this was the late tails to be blended back in. Quite cloudy. They don’t taste overly offensive but they are very acidic to my tastes (I’ve not pH tested them).

I’ll do the blending tomorrow.

FloridaCracker

I haven't ever had those smells come from my rum, either the wash or the distilling. The only "cheesy" smell was from the live dunder and that was minimal. Maybe you are on to something that we haven't seen before.

jacksonbrown

Don't know.
Maybe it's a waste of time. I'm just enjoying the exploring.
It certainly smells very different to the other rums I've made but I'm not experienced enough to predict what a few years on oak will do to it.
Trying to compare fresh off the still to the idea in my head of what a good rum is meant to taste like is very hard.
I'm starting to realise that there is a lot more going on in a barrel than just a bit of filtering and some oak flavor.

If all that acidity magically turns spew into pineapples then happy days but I'm not yet convinced.
I'm also using an American whiskey yeast this time which might have something to do with it.

Smaug

Yeast smells of burnt rubber when over exposed to copious amounts of heat.

jacksonbrown

Could be. I did reflux for 2 hours.
The wash settled for a day or two and I syphoned off the top so there shouldn’t have been too much yeast in there.
On clean-up the element didn’t look particularly fouled up either.
So my 2.2kW elements are 20mm by 290mm. I guess that makes them 75 - 80 W/in².
I haven’t had burning issues with them but I guess they’re a bit high for some wash types.

Burnt rubber is just what I’m calling it and is was localised around the tails cut that we discard anyway. The patent says –

"probably some sulfur compounds and organic volatile bodies probably of a xanthine
composition; all having a very bad odor"

That was a bit vague for me to decipher but perhaps someone else has some input on that.

jacksonbrown

Now that I think about it, vulcanised rubber is just rubber with sulfur added to it to cross link and toughen it up.
I guess that could be why "sulfur" compounds might smell a bit rubbery in my mind.

grim

Can you guys get Wray and Nephew out there? It's a good reference for funky.

grim

Or Hampden

jacksonbrown

Don't think so but I'll keep an eye out.

FloridaCracker

@grim said: Can you guys get Wray and Nephew out there? It's a good reference for funky.

Is that the "overproof" stuff? Had a taste in high school. Probably why I didn't drink rum for about 35 years....

FloridaCracker

I just did a spirit run on 10 1/2 gallons of rum. Collected 13 jars of different tails. Out of the 13 the first 3 or 4 smelled and tasted nasty. After that they almost all tasted and smelled good. I collected down to 60 abv before I pulled the plug. I'll give them 3-4 days and then evaluate. It seems like the more generations that I do (I'm on 10th gen right now) the more tails that are saveable. The one thing that I have noticed is that the first few jars of tails always seem rank. After that , it is a crapshoot.

jacksonbrown

So how many plates are you going through? I don't suppose you know the reflux ratio but do you know the power in and take off rate?
Sounds like we're seeing similar things.

FloridaCracker

4 plates and once I reach hearts I have a takeoff rate of about 7-8 liters per hour. The abv showing on the floating alcometer range was from 94 down to about 88 before I detected tails. The abv is not temp corrected and definitely off a bit. I also do a strip/spirit run. Tried doing it in a single run but didn't like the results. I also reflux for an hour before I start slowly taking fores/heads. The smell coming off of the still during the reflux definitely changes as it goes along. I can almost smell the esterfication happening. At the beginning of reflux, not much smell. By the end of the hour, tons of caramel, butter smells coming off.

Jon_o

@grim said: The Fragrance of Rum, Isobutyl Propionate (PDF)

I won't bother rambling about Fischer Esterification and Le Chatelier's principal.

OK - Cut to the chase...

So I've been re-reading this thread some of Arryo's patents and other Rum making documents again,

Some say that rum makers add carbolic acid during to the wash before distillation because carbolic acids act as a catalyst to the Fischer Esterification process.

Acetic acid is the second simplest carboxylic acid and Vinegar is roughly 3–9% acetic acid by volume.

Therefore is it possible to just add vinegar to the wash to improve esterification, or am i miss-understanding the process?

jacksonbrown

That would give the first column I think.
Depending on the alcohols present, mostly ethyl acetate.
I suppose you could add other stuff too but get the ferment right and you shouldn't have too.
You're not thinking of people adding acids as a catalyst are you? Like sulfuric etc.?
It would be good to hear other opinions on it but I think the catalyst acid has something to do with pulling the water away to let the reaction happen. We do this by refluxing so that might make the acid catalyst addition a bit redundant in our use.
We need to remember this product is for consumption too.

grim

I could think of a fun trial.

Run a rum strip, split the low wines into 3 parts.

Add sulfuric acid to part 1 Add nothing to part 2 Add bicarb or lye to part 3

Run the 3 in the same manner - compare. You should run the continuum from higher to lower esters through the 3.

On the acids - yes you can try these reactions in a small lab still using neutral or vodka as the base and procuring small amounts of the acids. Just don't forget to add the acid catalyst. I was able to buy propionic and butyric acid off of Amazon pretty easily.

grim

Or if you use lactic acid for mash pH adjustments, that would be a fun trial with a whiskey strip.

grim

BTW - if you aren't comfortable with the chemistry, you'd be best to ignore me. Posts above clearly require you to be comfortable working with dangerous chemicals and being able to test appropriately. Also assumes you can procure lab-grade reagents and food grade chemicals.

grim

Got a cold, couldn't sleep, was up at 4am reading obscure topics when I came across these two over at Boston Apothecary. Perfect for our discussion since they discuss pH and esterification during distillation. Especially since they seem to have done my proposed experiment (above) 50 years before I even thought of it.

P. LeH. Tummel. 1948. Acidity Modifies Brandy Composition @ Boston Apothecary

Couldn't help but post it here, since it is relevant to the discussions. As well this one:

H.T. Davoren. 1955. The Effect of pH on Brandy Composition @ Boston Apothecary

Specifically, take a look at the table and chart in the Davoren PDF (attached) , pages (numbered) 11 and 12).

And the conclusions:

1. Increased pH of base wine does give an increase in ester formation, with the maximum pH for such increase being about pH 3.0, but this might vary if only the brandy fraction of the run is taken.
2. The lower the pH of the base wine the more aldehyde is formed, which would probably necessitate the running of more spirit into the "heads" fraction when distilling low pH wines.

And the Tummel (trying to attach it, it's very large):

1. By reducing pH of base wine the ester content of brandy is increased.
2. Returning ‘heads’ and ‘tails’ from the brandy run to the next low wine charge causes an increase in esters, especially at pH .
3. Reducing the pH with sulphuric acids, besides being more economical, gives a higher ester content than tartaric acid, and at the required strength has no adverse effect on copper plate.”

H.T. Davoren - 1955 - The Effect Of pH On Brandy Composition (PDF)