Uh oh. Wild yeast? Infection?

[ba-brewer]

Onto more important topics, how does it taste, my good man?

hope you just didn't kill him to get your answer, hopefully it just numbs his tongue and he can still type.

For the record I'm curious too.

 

[foscojo]

You only got 67% attenuation from your numbers above, is this an extract recipe?

Yes

 

[Beermeister32]

There is too much sophistication on some of the above answers... I detect a Troll....

 

[VikeMan]

Beersmith gives a slightly different number sometime and I have a wort correction number for my refractometer.

Just a PSA here... I know some folks think of the wort correction factor (WCF) as a factor unique to their refractometer, and I've read articles written by people who should know better that implied that. But that's not the real purpose. A properly operating refractometer shouldn't need a unique one (for the particular instrument) . The real reason for the WCF is that refractometers are designed to measure sucrose concentrations, and the sugars/dextrins in wort are mostly not sucrose. And since sugar/dextrin profiles are different for each wort, ideally each wort would have its own WCF applied. In reality, most people use a single WCF for everything, maybe one that seems to give them the smallest error on average. What they are really chasing there is their own average wort.

 

[duncan.brown]

So is it dangerous to store unfermented wort?

If the wort has not been sterilized, then yes it is dangerous.

Will it be sterile enough to stay fresh and safe for more than a year?

Regular wort boiling at 212F at ~ 1 atmosphere will not sterilize wort and it will not stay fresh or safe for a year.

What if the malt or the hops were contaminated with C. Botulinum?

The spores could germinate, C. Botulinum could grow, and you could die from drinking it.

Boiling alone cannot deactivate the spores, that takes 250f+

Agreed. That's why anyone who makes wort for starters should use a pressure cooker and sterilize the wort at 250F (at 15 psi above atmospheric pressure) for at least 15 mins. Only when the wort and its container have been sterilized (not just boiled and sanitized) by pressure canning in sealed mason jars will it keep fresh for a year.

yet this not an uncommon practice.

I would hope people are only using these bags for the time it take ~ 5 gal of wort to cool from 212F to room temperature and are pitching yeast immediately and not using them to store wort for weeks.

It's true that nothing grows in beer will kill you because of the pH and alcohol content of finished beer, but stuff that grows in unfermented wort certainly can kill you. Death from food-borne botulism is fairly rate (something like 500 cases in the last 50 years), but it can still make you sick. The CDC says:

Many outbreaks of foodborne botulism in the United States result from eating improperly preserved home-canned foods. Persons doing home canning and other food preservation should
be educated about the proper time, pressure, and temperature required to destroy spores

 

[ba-brewer]

Just a PSA here... I know some folks think of the wort correction factor (WCF) as a factor unique to their refractometer, and I've read articles written by people who should know better that implied that. But that's not the real purpose. A properly operating refractometer shouldn't need a unique one (for the particular instrument) . The real reason for the WCF is that refractometers are designed to measure sucrose concentrations, and the sugars/dextrins in wort are mostly not sucrose. And since sugar/dextrin profiles are different for each wort, ideally each wort would have its own WCF applied. In reality, most people use a single WCF for everything, maybe one that seems to give them the smallest error on average. What they are really chasing there is their own average wort.

Thanks for the information. I should change the WCF in beersmith I put that in there 3 refractometers ago when I got my first one. I normally use a spreadsheet (seanterrill) to track my SG and not beersmith. I doubled check the spread sheet it does not have a correction factor. The final numbers are usually pretty close like 1 or 2 gravity points to the hydro but I really use it more to determine activity than the actual gravity.

 

[ba-brewer]

If the wort has not been sterilized, then yes it is dangerous.


Regular wort boiling at 212F at ~ 1 atmosphere will not sterilize wort and it will not stay fresh or safe for a year.


The spores could germinate, C. Botulinum could grow, and you could die from drinking it.


Agreed. That's why anyone who makes wort for starters should use a pressure cooker and sterilize the wort at 250F (at 25 psi above atmospheric pressure) for at least 15 mins. Only when the wort and its container have been sterilized (not just boiled and sanitized) by pressure canning in sealed mason jars will it keep fresh for a year.


I would hope people are only using these bags for the time it take ~ 5 gal of wort to cool from 212F to room temperature and are pitching yeast immediately and not using them to store wort for weeks.

It's true that nothing grows in beer will kill you because of the pH and alcohol content of finished beer, but stuff that grows in unfermented wort certainly can kill you. Death from food-borne botulism is fairly rate (something like 500 cases in the last 50 years), but it can still make you sick. The CDC says:

When I read the article posted by @Beermeister32 I immediately thought about the
LalBrew Köln dry kolsch yeast. That yeast takes days to get going from the time you pitch. In the article I think it said botulism needs under 2 percent oxygen to grow, I wonder if that should be ppm.

Fresh boiled wort should have a low oxygen content but If you aerate the wort prior to pitching the yeast would that provide enough oxygen for a few days to keep the botulism at bay?

 

[duncan.brown]

That yeast takes days to get going from the time you pitch.

It depends what you mean by "get going." Even before you get to high krausen, the yeast is acidifying the wort in its exponential growth phase. It needs the pH gradient to transport nutrients across its cell membrane and (helpfully to us and it) out compete other organisms by creating a low-pH environment. I'd have to check my brewing texts, but the pH drops pretty quickly from 5-ish to 4-ish and ultimately to the high threes for ales. And since pH is a logarithmic scale, one unit is really a factor of 10.

 

[ba-brewer]

Thanks @duncan.brown. By "get going" I mean there is no visible fermentation activity. Even when pitched at proper amounts it can take days before it showing active fermentation(krausen and CO2 generated). If it grows like all other yeasts it seems like that delay might be an issue.

 

[homebeerbrewer]

...
That's why anyone who makes wort for starters should use a pressure cooker and sterilize the wort at 250F (at 25 psi above atmospheric pressure) for at least 15 mins.

25 PSI? I've never seen, or heard, of a pressure cooker going that high. Mine goes up to 15 PSI, which is the highest I've seen.

 

[duncan.brown]

25 PSI? I've never seen, or heard, of a pressure cooker going that high. Mine goes up to 15 PSI, which is the highest I've seen.

Sorry, typo. I meant 15 psi. 25 psi would definitely blow the PRV on a normal home pressure cooker.

 

[duncan.brown]

Thanks @duncan.brown. By "get going" I mean there is no visible fermentation activity. Even when pitched at proper amounts it can take days before it showing active fermentation(krausen and CO2 generated). If it grows like all other yeasts it seems like that delay might be an issue.

Here's an article written for the home brewer by someone with a background in microbiology:

http://suigenerisbrewing.com/index.php/2020/01/29/botulism-in-beer/
tl;dr there's nothing to worry when home brewing about unless you store unsterilized wort in sealed containers for extended periods of time or try and capture wild bugs without pre-acidifying the wort.

Here's an interesting article in Frontiers in Microbiology where a group studied the growth and evolution of the organisms in lambic over time and shows the influence of pH on the organisms present:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6252343/

 

[duncan.brown]

BTW, I agree with @Beermeister32... the risk is small but life is too short to drink bad beer. I'd dump whatever was in the OPs fermenter...

 

[Andres Falconer]

This thread has inspired me. I just brewed a new batch, with the usual sanitary protocol. But found myself with plenty of extra wort, of decent-enough gravity, so I decided to try to brew a "wild small beer": I covered that second bucket with a cheesecloth and will wait to see what happens...

We must have all kinds of yeasts and bacteria floating around in the countryside, as we often make spontaneously-fermenting kvass and other stuff. It's never failed. And we're still alive.

If it smells good, I'll drink it. I'll post an update just to reassure folks I haven't died of botulism. All for science.

 

[Miraculix]

This thread has inspired me. I just brewed a new batch, with the usual sanitary protocol. But found myself with plenty of extra wort, of decent-enough gravity, so I decided to try to brew a "wild small beer": I covered that second bucket with a cheesecloth and will wait to see what happens...

We must have all kinds of yeasts and bacteria floating around in the countryside, as we often make spontaneously-fermenting kvass and other stuff. It's never failed. And we're still alive.

If it smells good, I'll drink it. I'll post an update just to reassure folks I haven't died of botulism. All for science.

Remove the cloth until it started to ferment! You can also put it outside to catch whatever the wind carries.

 

[Andres Falconer]

Remove the cloth until it started to ferment! You can also put it outside to catch whatever the wind carries.

It’s only one layer of very open mesh fabric - I thought it would help to keep away the flies, cat hair etc. I usually use a cheesecloth with kvass and other spontaneous fermentation. Do you think it’s important to keep it fully open?

 

[Miraculix]

It’s only one layer of very open mesh fabric - I thought it would help to keep away the flies, cat hair etc. I usually use a cheesecloth with kvass and other spontaneous fermentation. Do you think it’s important to keep it fully open?

Depends. Kvaas has other stuff in it that already carries yeast. Wort really needs stuff from the air so you might at least want to let it sit in the open for some hours next to some trees or flowers or whatever might contribute to stuff in the wind.

 

[cmac62]

This thread has inspired me. I just brewed a new batch, with the usual sanitary protocol. But found myself with plenty of extra wort, of decent-enough gravity, so I decided to try to brew a "wild small beer": I covered that second bucket with a cheesecloth and will wait to see what happens...

We must have all kinds of yeasts and bacteria floating around in the countryside, as we often make spontaneously-fermenting kvass and other stuff. It's never failed. And we're still alive.

If it smells good, I'll drink it. I'll post an update just to reassure folks I haven't died of botulism. All for science.

You should be good, an open fermentation is not anaerobic, there is plenty of O2 in and around the wort.

 

[ba-brewer]

There was something mentioned/recommended in the suigenerisbrewing link above to pre-acidify wort when doing coolship or open fermentations to help protect from bacteria.

 

[Andres Falconer]

Depends. Kvaas has other stuff in it that already carries yeast. Wort really needs stuff from the air so you might at least want to let it sit in the open for some hours next to some trees or flowers or whatever might contribute to stuff in the wind.

I did as you suggested and - we have ignition! Less than 24h after brewing. Nice activity and buildup on top of the wort. Doesn’t smell particularly yeasty at this point.

I like to believe that all the relevant bugs are already floating around in the house. We’re in a log cabin with plenty of natural ventilation in a field next to a forest. And there’s lots of fermenting of assorted kinds happening during this season. Mostly the wife pickling stuff or experimenting with weird types of kvass/gira with whatever is at hand. My last beer batch has a suspicious aroma of a cross-contamination of some sort of lactobacillus…

 

[Miraculix]

I did as you suggested and - we have ignition! Less than 24h after brewing. Nice activity and buildup on top of the wort. Doesn’t smell particularly yeasty at this point.

I like to believe that all the relevant bugs are already floating around in the house. We’re in a log cabin with plenty of natural ventilation in a field next to a forest. And there’s lots of fermenting of assorted kinds happening during this season. Mostly the wife pickling stuff or experimenting with weird types of kvass/gira with whatever is at hand. My last beer batch has a suspicious aroma of a cross-contamination of some sort of lactobacillus…

That sounds like the perfect environment for wild fermentation! Just don't bottle this in normal manner..... This stuff will continue forever to ferment.

 

[Garrett_McT]

Ya, I agree with @Jayjay1976 , how does it taste or smell!?!? have we come to a consensus that it was wild yeast? Did you take another gravity reading to see if it reached the FG?

Also, IMO I love refractometers for the ease of use and small sample sizes. I do about 3 gal batches and taking hydrometer samples really drains my bucket. I love BeerSmiths internal conversion, makes everything easy and in my experience it is pretty on point, thats of course if there is no operator error involved. I usually take like 2-3 readings with their own separate samples, especially with the fresh wort off the stove. If you don't mix the fresh wort it tends to get a really f-ed up readings.

Use the calculators, but even more so understand what goes into the calculators. Knowledge is power my friend. It has saved me a ton of money on buying needless products which are all over the brewing market.

 

[Garrett_McT]

That sounds like the perfect environment for wild fermentation! Just don't bottle this in normal manner..... This stuff will continue forever to ferment.

Wow, I didn't know that wild yeast tends to fermenting longer or more attenuatively?

 

[cmac62]

Wow, I didn't know that wild yeast tends to fermenting longer or more attenuatively?

Bugs can and do.

 

[Garrett_McT]

Bugs can and do.

I guess I do understand that it would ferment longer. I don't know why I said that. But honestly if the gravity hadn't stabilized yet I would never bottle.

I did that once with a summer shandy which oddly reached FG and I was holding it in the fermentor until I had time to bottle. Then a day or about 1.5 days go by then the fermentation took off again. I was extremely worried I had a contamination and for some stupid idea I thought that pulling it off the yeast and bottling it would stop the bacteria fermentation or whatever was causing the refermentaiton. Had a party to "tap the keg", but really bottles, and a few of them turned into bottle bombs. Luckily I tend to carbonate my beers high so I immediately pour the bottles into glasses, but as the night progressed and alcohol began to take effect friends would open bottles not pouring it and have a slow emitting volcano of foam. Fun fun

 

[Miraculix]

It's not the bacteria, it's the wild yeast. Some of them are diastatic and will bring the gravity down slowly. Usually it takes about half a year to one year to bring a wild beer to a stable fg.

 

[Andres Falconer]

That sounds like the perfect environment for wild fermentation! Just don't bottle this in normal manner..... This stuff will continue forever to ferment.

Let’s see what happens… I usually bottle any weird and wild stuff in PET plastic bottles, to be safe. And drink it very young. They are gushers!

 

[Miraculix]

Let’s see what happens… I usually bottle any weird and wild stuff in PET plastic bottles, to be safe. And drink it very young. They are gushers!

That's probably the best way. Once they are carbonated, you can slow everything down by storing them in the fridge.

 

[Timur]

it's the wild yeast
Brett yeast in other words, eh? Lambic-style beers, gueuze and everything that falls under the "barnyard-like" category.

 

[Andres Falconer]

This thread has inspired me. I just brewed a new batch, with the usual sanitary protocol. But found myself with plenty of extra wort, of decent-enough gravity, so I decided to try to brew a "wild small beer": I covered that second bucket with a cheesecloth and will wait to see what happens...

We must have all kinds of yeasts and bacteria floating around in the countryside, as we often make spontaneously-fermenting kvass and other stuff. It's never failed. And we're still alive.

If it smells good, I'll drink it. I'll post an update just to reassure folks I haven't died of botulism. All for science.

Update: (Not on the OP's wild yeast infection, but on my own very first crude and deliberate attempt at open/wild fermentation, inspired by this post - see above)

I got pretty decent activity in my open bucket after 24h, with plenty of krausen building up. I let it ferment for a few more days and bottled in PET plastic 1L bottles, for safety. The wort did not give off the usual yeasty smell, but it was not unpleasant, either. Clearly there was plenty of fermentation still going on, because the bottles puffed up rock hard after a couple of days. Even after refrigerating, the bottles gushed almost uncontrollably.

The result? Nothing smelling or tasting like (normal) beer. I took a whiff and a few sips. It had what I would describe as a sanitized hospital ward smell. Something like isopropyl alcohol. Perhaps like the band aid smell folks sometimes identify in brettanomyces. I dumped the whole small batch (it was just over 4L/1G of leftover wort from my "real" brew). If I was in prison or in a desert island I could see myself drinking it. It did not have a nasty taste, but definitely not good either. Is it likely that I just got a pure brett brew? On a positive note, I'm still very alive.

On a final note, can anyone point me to a good guide to help recognize and identify the most common "off flavors" (that can also be intentional components of some beers)?