What am I smelling?

[dragon613]

Just tried adding baking soda to spirit run for first time, and wow major improvement, I've had this pervasive smell/taste (smaste?) Without the soda, it's hard to describe in a single word... Musty? Oilly? Vaguely reminiscent of the scotch I buy myself for Christmas (Laphroaig) but only the "rank"-ness aspect, and on the tongue a lasting, "dirty" aftertaste

It's been detectable through the whole run and Ive been making my cuts to minimize it which has led to some very inefficient runs, and lots of recycling, and redistilling wasn't very effective,

Add some baking soda and poof it's gone, not just out of the hearts but the whole run, the heads and tails smelled way better, but now I want to know what I was smelling and why, if I want to make a fancy brandy or other flavoured spirit in the future I don't won't to wrestle with this must again.

I'm assuming because it dissapered with the soda that it should be an ester(I think) but idk of any ester described as smelling like this, I was just reading that isobutanol is described like my must but would that be eliminated by a base? I don't think so, what about an organic acid like butyric acid, I know vinegar is produced by distillation, maybe others can vapor over too? If that were the case the base treatment would neutralize, idk just thinking out loud

Oh and the wash I use, is sugar/fruit based, I keep it below 14%abv and around 20-50% of wash volume is fruit puree, I use redstar cotes de Blanc or cuvee yeast, I ferment very cleanly and my wash is drinkable on it's own,

no infections, so that all but rules out butyric acid


And it's not the condenser it's been thoroughly cleaned and used several times

It may seem strange to ask why I was having a problem after I've already solved it but the resulting likker was very "neutral" and I'm not sure that's what I want, especially when I'm spending money on fruit

[still_stirrin]

Fermentation produces acids. And those, typically will “smell” sour. But some may smell “musty” not unlike the smokey quality you get from the Scotch. The acids are an intermediary product, however, during the reduction of sugars to alcohol. So, you probably don’t have to worry about them. I usually don’t smell my active ferments because they stink and the CO2 “tingles” in my nose.

Adding baking soda (sodium bicarbonate) didn’t hurt your ferment, in fact it may have helped (a little) by neutralizing some of the acids. But, if you’re trying to raise the pH, then there are better choices to use because baking soda would add too much sodium to the ferment, potentially hurting the yeast (which don’t like sodium).

And who knows what kind of spores were added on the skins of the fruit you added to the must. There could be some contamination added there that was stinky. Whether or not it would affect the flavor of the wine only you will know.

You’re probably OK though, so carry on.
ss

[Tummydoc]

He didn't add it to the ferment, he used it to clean up a stripping run. I'd guess you hydrolyzed some ester. I've only used it to minimize ethyl acetate which is sweet, so not a clue as to what you cleaned up.

[jonnys_spirit]

Did you add it to the low wines or the must/wash? Did you follow a strip/spirit protocol? Low wines can be pretty nasty but they clean up real nice in the spirit run.

Cheers,
Jonny

[dragon613]

Yeah added to low wines for spirit, I know not to add base to wash, cuz of ammonia and corrosion

I've run spirits without soda and it hardly affected the must smaste (if anything it seemed to make it worse because whatever it was there was more of it present)

My "wash" is really just the same recipe and procedure I use to make fruit wines without the cold crashing step, so I hoped that my esters would be the good flavorful kind, not the sweaty sock kind, maybe there's just too much esters present? And maybe a small amount of soda at the spirit run, or even pH balancing before the ferment with potass. Bicarb to reduce free acid could reduce the esters to an appreciable concentration?

Guess I'll just have to try and report back

[jonnys_spirit]

It might be smearing? Can you post some photos of your setup? How are you running it and doing your cuts?

Cheers,
Jonny

[30xs]

What is your column made of? Any copper in the vapor path? A buddy of mine did his last run through a stainless column without scrubbers, accidentally, his last run. The smell from the jars were similar to what you’re explaining. I didn’t taste, but do you blame me?

[dragon613]

Stainless keg, copper condenser pot still, I doubt it's smearing because I run it so slowly, around 1L per hour or less, I could probably run faster but I'm gun-shy after experiencing a boilover one time.

And like I said, it wasnt there anymore after base treatment

Also, has anyone else tried this? I connected my keg and copper by using a 2-1/8" hole saw to cut a plug out of some oak, fits perfectly and seals real nice with paste