How long does yeast remain active after bottling?

[The Experimenter]

I don't know if this happens to everyone (I've only heard a few other people talk about it before), but drinking a brew with yeast that is still active in it makes me sick (usually not right away, but by the morning I'll be feeling it in my gut and will feel it for the rest of the day). As such, I am always trying to make sure the yeast is no longer alive / no longer active whenever I drink one of my homebrews.

I don't use Sodium Metabisulfite or Potassium Sorbate or any other chemicals to halt fermentation or to kill yeast. I don't got anything against the use of any of those chemicals, I'm just lazy and never bought any of them (yet). Instead, I just let the yeast do its thing until they stop on their own. I have tried heat pasteurizing wines, meads, and ciders after bottling, but it's not something I normally do because it is a process that takes time, energy, and planning (and once again, I'm lazy). Normally, I just cold crash my brews before consuming them (not for clarity, but to force the yeast into dormancy). This seems to work for me... I've never gotten sick from a chilled brew.

However, there are some brews I don't want to have to chill, mainly my wines (chilled wines are fine, I just don't want to HAVE TO do it). I'm relatively new to homebrewing and my first wine just hit 2 months of aging. I know that's still pretty young, but I wanted to try 1 bottle of it now just to see what it's like. As I was grabbing a bottle of it I paused to wonder... do I need to cold crash it? Is it possible that after 2 months in a closed system with no fresh sugars, nutrients, or oxygen that there are still yeast in there that are active (or that might easily reactivate when I drink it)?

So how long can yeast remain active in a brew after bottling? I know there are a ton variables to consider, but generally speaking what is the longest you'd see yeast remaining active for in a closed bottle during aging?

P.S. - I know some people are going to respond saying that if I have no problem with using the preservatives I mentioned to stop the yeast, then I should just start using them and then I don't need to worry about all of this... and maybe you're right, but that doesn't change the relevancy of this question in regards to the wines I've ALREADY bottled.

 

[Erik the Awful]

Here, I'll make it easier for you. I was losing one in every three batches before I started using campden tablets.
https://www.amazon.com/gp/product/B07JMH97SK/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
I resisted using campden tablets for a while as well, but I'm glad I started. I'm not too far advanced from where you're at now. I just started my 24th wine batch - I've been averaging one a month lately.

 

[IslandLizard]

3-6 months.

 

[The Experimenter]

3-6 months.

So 6 months is the upper range of time? After 6 months I can be fairly certain any yeast is dead or dormant?

 

[Yooper]

So 6 months is the upper range of time? After 6 months I can be fairly certain any yeast is dead or dormant?

Well, maybe.
The key is to bottle only super clear wine, so there is very little yeast present. That means it may need to sit in the carboy for 6 months or more, and you want to rack whenever you have lees (sediment) 1/4” thick or more, or any lees at all after 60 days. Once you aren’t dropping any lees at all in 60 days, it’s worthwhile to put the fermenter someplace cooler (like a basement) and even more yeast will drop out. If you can hold it at 40 degrees for 30 days or so, and it’s crystal clear, and then rack it off any lees, you will have very little yeast in the bottles.
THAT is the time to bottle, not when the wine is only a couple of months old!
I won’t say none at all (yeast is microscopic) but I have bottles that are years old with no sediment at all in them.

 

[Yooper]

And I think you’re making wine, right, not brewing? I just want to make sure I understand exactly what you’re making because beer is different (you need yeast to carbonate the beer).
You’re not brewing, you’re making wine, correct?

 

[The Experimenter]

And I think you’re making wine, right, not brewing? I just want to make sure I understand exactly what you’re making because beer is different (you need yeast to carbonate the beer).
You’re not brewing, you’re making wine, correct?

I do everything... Wine, beer, cider, mead, even skeeter pee (as my name implies, I like to try new things and see what happens... I even experiment with Kilju/sugar wine). I know it's not correct, but I use the term "brewing" as a catch-all term to describe putting yeast into a must/wort/whatever other names there might be for the liquid mixture with the sugars the yeast want to eat and letting them go to work doing so. Regardless of whether it's beer or wine or cider or whatever, it's the same basic process. Put yeast in an environment where they'll thrive and sit back and let them do their thang.

My question was meant to apply to any such "brew", but I used the example of a wine (and posted in the winemaking forum) because that is the only type of homebrew that I don't always automatically chill (I even prefer my mead chilled), so my wine is the only thing I brew that this question really needed an answer for. That doesn't mean I'm not curious how many months I would need to wait to drink a room temp cider or skeeter pee... it's just that I'm never actually gonna try it because I prefer those ice cold anyway and I usually drink them all before they come anywhere close to anything you could call "aging" lol.

... But yes, I understand I am not "brewing" when I'm making wine. That's just what I call it and sometimes I forget to use the correct terms when I come on this site to ask questions.

 

[Yooper]

Ok, I understand. “Brewing” means applying heat- like brewing coffee or beer. Anyway, semantics aside........

Wine really is a different process in many ways- partly because of wanting to remove most of the yeast before bottling unlike with beer or kombucha making.

If you want to have most of the yeast gone, it takes time. Even if you sterile filter, you only can filter a clear wine. If you bottle it without it being really clear and no longer dropping lees, the yeast in the bottle will remain alive (dormant, but alive) for possibly years.

 

[Raptor99]

Ok, I understand. “Brewing” means applying heat- like brewing coffee or beer. Anyway, semantics aside........

There is also cold brew coffee. But other than that I think you are right about the correct meaning of "brew." We need a general term that covers making wine, mead, cider, and beer. Could we adopt "brewing" for that? Do you have any other suggestions?

 

[The Experimenter]

There is also cold brew coffee. But other than that I think you are right about the correct meaning of "brew." We need a general term that covers making wine, mead, cider, and beer. Could we adopt "brewing" for that? Do you have any other suggestions?

We could start using Ferment as a noun and/or verb (I know it's already a verb, but I mean we could use it as a verb for an action that we do, not just that the yeast/must does), i.e. "The other day I was working on a new white wine Ferment. But tomorrow I think I'm gonna start Fermenting a cider Ferment with this cool recipe I found on HomeBrewTalk".

I prefer to say Brew/Brewing tho, even if not correct, but I do use the word Ferment in my head almost interchangeably sometimes.

 

[Beermeister32]

If you drink a bunch of bottle conditioned beer you are supposed to decant the beer off the “lees” or “dregs”, the remaining yeast slurry at the bottom of the bottle. By the way, the “dregs of society” was once a term for creepy weird or dirty people based on this.

100 years ago, many beer bottles had a neck label instructing you to turn the bottle upright for a day or so, chill, then carefully decant the beer off the yeast. This way you aren’t drinking live yeast. It’s going to be there live or dormant for years and years.

The thing is, if you drink in a bunch of yeast, it can begin to ferment any available undigested sugars in your gut. It throws off CO2 gas which causes bloating pain and diarrhea. I drank about a half rack of Sierra Nevada years ago before understanding what our grandfathers knew decades ago. They called it “billousness” back in the day. Undercooked bread and pizza dough also can do the same thing if the yeast hasn’t cooked out.

So decant your beer carefully, leave the yeast behind in the bottle and watch out for those heavy yeast-laden beers like Hefeweizens!

 

[Beermeister32]

Here’s a fun clip of Carsberg resurrecting 1880’s yeast. It’s always there!

 

[Yooper]

I was thinking more about this, about how long yeast can remain active and I just remembered that I used to make a ton of bread and I bought a huge supply of bread yeast. I kept it in the fridge for years, long after I went low-carb, because I hate throwing things away. It had been opened, and at approximately 40 degrees, and expired probably around 2010. I ended up using it during Covid when it was hard to find yeast and I wanted to make some rolls for Easter dinner. It was fine!

I keep brewing yeast in my fridge in mason jars for repitching, but I’ve never kept it more than a year or so. I imagine it could get stressed, and even undergo autolysis, but still have the capability of fermenting if even two yeast cells remain.

 

[The Experimenter]

capability of fermenting if even two yeast cells remain.

Why two yeast cells... I mean I know yeast can reproduce sexually, but isn't yeast reproduction normally asexual? Wouldn't there be a capability of fermenting even if only 1 yeast cell/spore remained?... This isn't an important question, I'm just curious why you said 2.

 

[The Experimenter]

Here’s a fun clip of Carsberg resurrecting 1880’s yeast. It’s always there!

This really is impressive... I mean I knew they could last a while (I figured like a few years maybe), but that is crazy long!

 

[bernardsmith]

My understanding is that yeast cells can survive - quite literally - millennia. Yeast simply go dormant. They don't necessarily die. This NYT story suggests that after 4,000 years you can still revive dormant yeast.

https://www.nytimes.com/2019/08/08/science/egyptian-yeast-bread.html
If you are sensitive to yeast then you may need to either be sure to remove every last cell through sterile filtration or you may need to chemically kill every cell.

 

[Yooper]

Why two yeast cells... I mean I know yeast can reproduce sexually, but isn't yeast reproduction normally asexual? Wouldn't there be a capability of fermenting even if only 1 yeast cell/spore remained?... This isn't an important question, I'm just curious why you said 2.

Well, two are double the amount, so if one is not as viable, the other one might be. Could be 1, could be 50, could be 100,000. Some could be dead, some may just be dormant, but if there is more than one odds are much better.

 

[The Experimenter]

If you are sensitive to yeast then you may need to either be sure to remove every last cell through sterile filtration or you may need to chemically kill every cell.

I'm not super sensitive. I've just had 1 or 2 bad experiences before in which drinking a fresh (less than 1 month old) room temp brew (even one that appears crystal clear) caused my stomach to be turning for the next 12-24 hours. It's not the end of the world when it happens, but it's also not fun, so I just try to avoid it when I can. As I said, cold crashing tends to work for me, but I don't prefer all brews (or wines or whatever) cold.

I should look more into chemicals and things like that to stop them... Or I should just get used to pasteurizing (it's not like it's super hard or anything, it just takes time and precision).

 

[The Experimenter]

I thank all of you for the great responses and info and details (and links) about the longevity of yeast, especially once it has entered a dormant state which it can apparently stay in for millenia!... but I'd like to steer this conversation back toward part of my original question:

How long can yeast remain active in a brew after bottling?

Again, I appreciate the discussion over the past half-dozen posts or so about yeast remaining alive (but dormant) for centuries... that was part of my question, but so was the part about them remaining active. How long do the yeast continue to move, reproduce, etc. after bottling... iow, they may be able to remain dormant for eons, but how long do they remain active before entering that state of dormancy? I know the answer will vary due to numerous variables, but what's the general range of time? (if there is a known range of time for this... I'd imagine this would be a difficult thing to study. It would involve periodically opening bottles before they've fully aged, checking if any yeast in a random sample from the bottle were dormant or active, and then wondering if they were still active just before you opened the bottle or if they reactivated sometime after opening the bottle but before getting them under the microscope... so I understand if this is something there isn't really an answer to).

 

[Beermeister32]

Probably months or years. My guess is it is more an issue of quantity of yeast consumed and whether your stomach acid is able to knock out the yeast before entering the intestines. Beer drinkers drink a LOT of fluid, beers being about 90% water. My guess is the stomach acid can get diluted enough to let live yeast into the intestines, which causes problems. Like in all things, it's not the poison.... it's the dose!

 

[bernardsmith]

The yeast return to activity as soon as their is a sugar source for them to feed on. If that is in the bottle then they are active in the bottle as long as there is a source of food and if that source is now your gut then even if they have been inactive for months they can become re-animated and gorge on food sources in your gut. I guess I would treat your question as one not focused on the real issue which has little to do with their inactivity in a bottle. THAT has to do with whether the bottle contains any source of fermerntable yeast hitherto untouched by the yeast. Once all the sugars have been consumed then given the actual longevity of any cell kept dormant can be several thousand years then my answer would be if the acids and other material in your gut don't immediately autolyse the yeast cells (your stomach can compete with your car battery for acidity) AND the yeast have a good source of fermentable sugars in your gut And that might be a rare event - see the acidity of the stomach and the microbial activity that takes place to break down food, then you need to assume that unless you know the yeast have been either chemically eliminated or have been filtered out of your wine they are gonna be active in your gut.

 

[Beermeister32]

Looks like there is a medical term for it. “Autofermentation” or “Autobrewery” Syndrome. Cheers!

 

[bwible]

If you drink a bunch of bottle conditioned beer you are supposed to decant the beer off the “lees” or “dregs”, the remaining yeast slurry at the bottom of the bottle. By the way, the “dregs of society” was once a term for creepy weird or dirty people based on this.

100 years ago, many beer bottles had a neck label instructing you to turn the bottle upright for a day or so, chill, then carefully decant the beer off the yeast. This way you aren’t drinking live yeast. It’s going to be there live or dormant for years and years.

The thing is, if you drink in a bunch of yeast, it can begin to ferment any available undigested sugars in your gut. It throws off CO2 gas which causes bloating pain and diarrhea. I drank about a half rack of Sierra Nevada years ago before understanding what our grandfathers knew decades ago. They called it “billousness” back in the day. Undercooked bread and pizza dough also can do the same thing if the yeast hasn’t cooked out.

So decant your beer carefully, leave the yeast behind in the bottle and watch out for those heavy yeast-laden beers like Hefeweizens!

I’m surprised how many people believe they are supposed to shake up the yeast off the bottom - I see this especially with wheat beer. People actually believe they are supposed to mix the yeast back in.

Some homebrews give me bad gas when I drink more than one or two. I always believed this was due to yeast and homebrew not being filtered like many commercial brews. Thats about the worst I ever get.

I’ve had people say homebrew is more “filling” and they can’t drink as many. Like the guys that are used to pounding a 12 pack of Bud.

 

[The Experimenter]

Some homebrews give me bad gas when I drink more than one or two. I always believed this was due to yeast and homebrew not being filtered like many commercial brews. Thats about the worst I ever get.

Same, that's the worst I get. I'm not saying what I get is super bad... but having a stomach ache and being gassy is something I'd rather avoid, so that's why I started this thread and asked the question.

 

[The Experimenter]

Looks like there is a medical term for it. “Autofermentation” or “Autobrewery” Syndrome. Cheers!View attachment 718845

Auto-Fermentation is a rare condition in which the body ferments alcohol on its own (without drinking yeast from homebrews). It is an extreme condition with extreme side effects and health concerns.

That IS NOT what I have. As I said in an earlier post in this thread, what I get is not super bad. I get a stomach ache and gassiness for the next 12-24 hours. That's all. But it is still something to avoid because it is unpleasant and uncomfortable and that is why I started this thread and asked my original question.

Cool resource you sent though, I like the visual diagram.

 

[AirLock Sniffer]

Hope it isn't bad form to bring up an older thread, but I sure do love the internet search engines when it actually understands my question. I figured (rightly) that this question has been asked on this forum. Sho nuff.

I was "wondering" if there were any viable Yeast yet alive in my 2 year old Hefe's. I thought "maybe", but they are done with all the sugars, right? As far as 2 year old homebrew, I suppose maybe someone would allow they are getting a little "stale" or oxidized, but it tastes damn fine to me, better than any commercial brew. But I'm not too picky. They never did taste particularly like a German Hefe, but it sure is excellent beer. I managed to get a high school buddy snockered at a reunion, he was impressed and wants to get into brewing. Anyhoo.

The reason I wondered was twofold I guess. One, I've heard it's important to maintain a healthy "biome" or somesuch, in our guts. This is true (so they say) after a round of certain antibiotics or other medicines. The "flora" can change. And I figure, a good beer yeast is just what the Doctor ordered, right? Those Germans told me they would "prescribe" 2 beers a day. So I'm going to do that. I still have a metric crapton of beer, I don't do carbohydrates too much, but I'm starting to like beer again.

Second, I was wondering if it was possible to cultivate the yeast from a bottle conditioned home-brew after a couple years, if necessary, as a kind of starter. It looks to me like the answer is "Yes", assuming the beer hasn't been exposed to excessive temperatures along the way. That is remarkable!

Here's to healthy gut-critters! Cheers.

 

[IslandLizard]

I was wondering if it was possible to cultivate the yeast from a bottle conditioned home-brew after a couple years,

Yes, it's possible, also from commercial beer as long as it wasn't pasteurized along the way. IIRC, certain commercial filtering also removes the yeast. Most (larger) breweries now centrifuge the beer while transferring to the bright tank. That may or may not remove all yeast cells, not sure if there are levels of removal to that.

Theoretically you'd only need one live cell... but there could have been mutations along the way, so it's best to harvest at least a somewhat larger culture.

Search for "culturing (beer) dregs."
Even dregs from 3+ year old Lambics are being cultured, and even isolated. Or sometimes pitched directly to enrich the microbiome in a fermenting batch of beer.

 

[IslandLizard]

I was "wondering" if there were any viable Yeast yet alive in my 2 year old Hefe's.

There could be, but why not buy/use freshly bought yeast, liquid or dried. There's an abundant selection more or less readily available of both types (dry and liquid).
Before use it's best to build starters from those yeasts, and overbuild them (make more than you need to pitch) so can save some out for a next round, which you also overbuild, etc.

Last year I made starters from a whole bunch of liquid yeast strains, some I had bought in 2013, and had been stored in the fridge since. They were all successful. Now for long term yeast storage, freezing (with some glycerine) is preferred. I'm working toward doing that now.

 

[Maylar]

What kind of wine is a Hefe?

 

[AirLock Sniffer]

Yes, this IS the winemaking section. Heaven forfend.

I do wish to apologize if I offended the more refined and rarified, delicate sensibilities. I denounce myself!

 

[mac_1103]

Autofermentation syndrome doesn't have much to do with wine either.

 

[IslandLizard]

Yes, this IS the winemaking section.

I was aware of that.
In the first part of your post you were hooking into the gut flora/biome aspect that was being addressed in the thread. So I let it be.
The second part of your post is much more off-topic, as cultivating yeast from bottled wine is far less common than from beer.

I'm suggesting we're moving your post and all subsequent ones to their own thread in the Fermentation & Yeast forum.
And add a link to the latter post(s) in this current thread dealing with auto-fermentation syndrome.

OK?