Is it possible to ferment too long?

[theshoeshiner]

I started a batch of scotch a long while back, and then got caught up with some over things and it's been in my closet now for about 4 months. Alcohol content is high and obviously all fermentation has stopped. It's been air-locked and I don't see any signs of mold growth.

Is this safe to distill? I understand that distilling will basically kill anything living organism that might still be in it, bacteria or otherwise, but I don't want to distill it if it's slowly been creating non-desirable alcohols that I'll have to worry about being in my final cuts.

Any guidance?

Edit: Said "ferment" when I meant "distill"

Edit: Thanks for all the replies! I ran it today and looks like it turned out just fine. No vinegar smell, no off colors, everything looks good!

[still_stirrin]

Run it.

Fermentation has stopped and its been sitting for months. Probably cleared and ready to rack into the boiler. Do it already.
ss

[thecroweater]

In all likelihood it's just fine and if it's sub par shit happens. Once you open it run it sooner rather than latter.

[Pikey]

Yeah depending on your OG - you've either made wine or beer - without air - either of those will be absolutely fine to run

[Anyhowe]

You can look up autolysis of yeast. Likely not an issue for you but: 1) you will know by smell and taste if this has occurred. It will be nasty. 2) a real problem for beer, likely not for distilling unless it has a bad burnt rubber smell. I think that could be problematic. Again , all of this is doubtful anyway assuming reasonable temps.

[ShineonCrazyDiamond]

The longer it sits (safely), the better it is. Once ran an UJ that sat for almost a year. Best damn Uj I ever did. No sugar bite, smooth.

Lucky bastard

[zach]

I recently had my first fail, not sure how old , but it was at least two months. A vinegar bug had taken over and consumed most of the ethanol. It was a sugar head using the spent grains from a beer. I should have tossed it, but I tried to distill it. I've discarded the bucket as I can't get the smell out of the plastic.

Prior to this I've had 3 or 4 month old ujssm wash that was clearly infected that made good liquor. I would run it, unless you smell or taste vinegar.

[Anyhowe]

The longer it sits (safely), the better it is.

Lucky bastard

Really? What improvement happens after fermentation is done and the wash has cleared? Inquiring minds would like to know. Thanks.

[ShineonCrazyDiamond]

Why does wine and most beer get better after sitting? Ever tried green cider vs cider over 6 months?

There are alot of sciences that I don't understand. I do know that yeast will continue to clean the ferment up for months after it is done. I only talk from experience, not in knowledge .

Im not suggesting that the payoff in distilling is worth the extra wait, since we have the option of throwing away the unwanted parts after distillation, unlike beer and wine. But the ferment definitely clears, cleans itself, and settles 8in . No harm in letting it sit sealed up.

[Anyhowe]

Why does wine and most beer get better after sitting? Ever tried green cider vs cider over 6 months?

There are alot of sciences that I don't understand. I do know that yeast will continue to clean the ferment up for months after it is done. I only talk from experience, not in knowledge .

Im not suggesting that the payoff in distilling is worth the extra wait, since we have the option of throwing away the unwanted parts after distillation, unlike beer and wine. But the ferment definitely clears, cleans itself, and settles 8in . No harm in letting it sit sealed up.

Hmmm, ok first off I assume the OP has figured out he is likely fine. Beyond that I suggest anyone reading this thread that really wants to learn the ins and outs of AG mashing, fermentation, diacetyl rests, wash clarification, lagering etc go to homebrewtalk.com. Beer guys, by necessity, are way ahead here.

[thecroweater]

Yes and no, they have a different aim so employ some different methods

[Single Malt Yinzer]

The longer it sits (safely), the better it is.

Lucky bastard

Really? What improvement happens after fermentation is done and the wash has cleared? Inquiring minds would like to know. Thanks.

Yeast will clean up diacetyl (and other byproducts) once primary fermentation is complete. Diacetyl is a byproduct of primary fermentation. Letting yeast process diacetyl will reduce/remove the buttered popcorn flavor. Some consider it a fault, some like it.

Autolysis will release yeast cell contents. It is in essence the enzymes from the yeast eating the cell walls. This is a mixture of a lot of different things: some good, some bad. It depends on your personal palate/taste the same as the diacetyl.

The dangers of a long ferment: Acetic acid bacteria. The vast majority of infections will not affect the alcohol content of your wash - and usually make them taste better. Most acetic acid bacteria like aerobacter will process the alcohol into vinegar (acetic acid). Most acetic acid bacterias require oxygen to process the alcohol so it's easy to avoid with a closed ferment.

If you run a closed aseptic wash (following proper sanitation protocol) you can let it go for as long as you like. One thing to watch for is that most plastic carboys/buckets WILL allow small amount of oxygen through.
Personally I don't run things until they are 6-8 days old. I open ferment so I don't let it sit longer than that in case I do get a bad infection.

[Single Malt Yinzer]

Beyond that I suggest anyone reading this thread that really wants to learn the ins and outs of AG mashing, fermentation, diacetyl rests, wash clarification, lagering etc go to homebrewtalk.com. Beer guys, by necessity, are way ahead here.

Huge difference between beer and distilling. I've always found that beer guys have the hardest time dropping the beer mentality and diving into the distilling side of the above. A lot of the things that are common protocol in beer hurt the outcome in distilling. The means are similar but the ends are vastly different.

Example differences:
- My grinds are way smaller. Roughly corn flour like. I squeeze the grains when done and I don't care about tannin extraction.
- With AG single malt I mash at 140-145. I want to dry it out as much as possible and keep the enzymes. Any non-fermentable sugars are a waste of money. Others here mash even lower.
- No crash cooling. I let it drop on it own. Once it's close to 100 I pitch yeast.
- No boil when done. I want the enzymes to keep doing their thing as it ferments. I don't care about bacteria. And you'll see later I encourage it.
- Open ferment. No sanitation, I only clean the fermenting kettle with water and PBW.
- I do water bath the kettle with an aquarium heater to maintain temp. Normally high 70s to mid 80s, sometime higher. I let it heat up as much as it wants but the water bath will limit.
- Speaking of bacteria I load it up on day 2 to with dunder. At this point the wash is non-potable. Bacteria help make feedstock for esters. I want esters. Lots of them.
- Increase temp ~1 degree on days 3-8 to get down to 1.000. Again, I don't want any sugars left, it's a waste. The idea is to make alcohol.
- I don't clear the wash. I dump everything including the lees into the still.

The above would make a horrible beer but a great Scottish style single malt.

[Anyhowe]

Beyond that I suggest anyone reading this thread that really wants to learn the ins and outs of AG mashing, fermentation, diacetyl rests, wash clarification, lagering etc go to homebrewtalk.com. Beer guys, by necessity, are way ahead here.

Huge difference between beer and distilling. I've always found that beer guys have the hardest time dropping the beer mentality and diving into the distilling side of the above. A lot of the things that are common protocol in beer hurt the outcome in distilling. The means are similar but the ends are vastly different.

Example differences:
- My grinds are way smaller. Roughly corn flour like. I squeeze the grains when done and I don't care about tannin extraction.
- With AG single malt I mash at 140-145. I want to dry it out as much as possible and keep the enzymes. Any non-fermentable sugars are a waste of money. Others here mash even lower.
- No crash cooling. I let it drop on it own. Once it's close to 100 I pitch yeast.
- No boil when done. I want the enzymes to keep doing their thing as it ferments. I don't care about bacteria. And you'll see later I encourage it.
- Open ferment. No sanitation, I only clean the fermenting kettle with water and PBW.
- I do water bath the kettle with an aquarium heater to maintain temp. Normally high 70s to mid 80s, sometime higher. I let it heat up as much as it wants but the water bath will limit.
- Speaking of bacteria I load it up on day 2 to with dunder. At this point the wash is non-potable. Bacteria help make feedstock for esters. I want esters. Lots of them.
- Increase temp ~1 degree on days 3-8 to get down to 1.000. Again, I don't want any sugars left, it's a waste. The idea is to make alcohol.
- I don't clear the wash. I dump everything including the lees into the still.

The above would make a horrible beer but a great Scottish style single malt.

Excellent post. Great display of knowledge of the topic. My reference to the brew site was to gain insight from a group whose craft has mashing and fermenting as a foundation. A descent novice AG brewer is aware of the effect of subtle changes in mash and fermentation temps, ph etc. I did not mean do it like them but simply to learn. Sorry for the confusion.

Fwiw and we can consider this thread completely hijacked this is my process:

- I crush the same. The best setting is the best setting for ones process. A stuck mash is a stuck mash
- I mash at the lower end of the scale but at 152. Curious as to what the FG would be at 145
- don’t sweat what’s left in the grains so I don’t over sparge or squeeze
- boil for 10-15 min. I hate bacteria and it separates the hot break.
-immersion chill 70 degrees (5 min)to avoid increase in dms. Warm wash is also susceptible to contamination. (Did I mention I don’t like bacteria?
-ferment in sanitized stainless, under 5 psi pressure at 70 degrees. I am not in a hurry and I don’t like esters.
- bump a few degrees at the end to help finish
- chill to 40 degrees and use gelatin to clarify to get a crystal clear wash

There is much to learn and I hope I never stop. Thanks again for the informative post.

[Anyhowe]

@single malt yinzer I have a fully automated system I can program to do what ever I want for as long as I want at what ever temp I chose. You now have me thinking. Here is a little paragraph on mashing that you may have seen. I may try some creative mashing profiles to see the affect of FG. Thanks again for the post.

“German brewers commonly apply a multi step saccharification rest to achieve better fermentability. As noted above, the genatinization of barley starch happens between 140ºF (60ºC) and 150ºF (65ºC) [Palmer, 2006]. This means that at the optimal temperature for beta-amylase not not all starch may have gelatinized and is accessible to the enzymes. A multi step saccrification rest would employ a first rest between 140ºF (60ºC) and 150ºF (65ºC) which gives the beta amylase plenty of time to produce maltose from the accessible starches. Due to the limit dextrinase and already existing alpha amylase activity, the 1-6 links of amylopectin don't pose a limit for the beta amylase. This rest is commonly known as maltase rest. The lower the temperature of this rest, the longer the beta amylase will last and the more maltose is produced which increases the fermentability. Since the mash is generally not completely converted after the 30-60 min maltose rest, a second conversion rest, called saccharification or dextrinization rest is employed. This rest is held between 160ºF (70ºC) and 164ºF (72ºC) which is well above the gelatinization temperatuere for barley starch and within the optimal temperature range for alpha Amylase which will quickly convert the remaining starches. This rest is usually held until conversion of the mash is complete. An other benefit of this rest is the formation of foam positive glyco proteins [Fix, 1999][Narziss, 2005]

If even better fermentability is desired, multiple rests within the beta and alpha amylase temperature range are possible. Such a mash schedule is used by Anheuser Bush to brew Bud Light without the use of enzyme additions in the mash. In order to leave as little dextrines as possible, their saccharification "rest" takes 2 hours while they slowly step the mash from 140ºF (60ºC) to 160ºF (70ºC) [source ??]. Such a mash schedule could be used by home brewers to brew highly attenuated styles like Belgian Saisons.”
.

[Distilaholic]

Snip.

How long do you age it for? 100f seems high to pitch yeast and be able to make tight cuts.

I used to pitch at 86f but lately I pitch lower am able to make tighter cuts + don't have to age as long before it gets real smooth. I guess I am trading away conplexity though.

[Single Malt Yinzer]

yeah so we're off on a tangent - starting a new thread: viewtopic.php?f=3&t=72747