Spontaneous Fermentation - Now What?

[FunkedOut]

Exactly one week ago, I had a brew day where I made two batches.
Each one, left ~1/2 gallon of wort in the kettle with all the break material.
I drained each into an empty water jug and sealed it up tight to discard later.

Next day, I walk out into the garage and see they’ve settled a decent amount, and I get the idea to loosen the tops to see if they’d catch anything wild that would ferment.
Garage spent that whole day wide open with the jugs on the floor at the edge of the garage.
Yeasterday, I walked out to the garage a saw a very active fermentation going on in one of the two jugs! The wort is no longer clear, and I can see bubbles rushing up the side of the jug. Smells like, beer.
I poured a bit of it into the other jug.

This is Florida, ~70*F out and lots of oak trees, pine trees and palms around.
Washing my car is useless these days, as the very next day, the car is covered in a green haze; oak pollen.

I had planned on letting finish in place, then cold crashing and bottling.
If it tastes good, I plan on keeping a culture on hand.

This is new territory for me.
Anything I should know?
Any advice?
Thanks in advance.

 

[kh54s10]

Now that it is fermenting, you are either culturing bacteria and could get a good sour or something undrinkable. Or, you have a wild yeast and will get a regular beer, which could also be anywhere from great to undrinkable. Or you have a combination of organisms which will produce the same results.

I would treat them like any other beer at this point. Control the fermentation temperature. Let it ferment out. Then you could give them a taste and see if you got a culture you would want to save.

I captured what I believe was a wild yeast once by dropping a rose bloom into a starter wort. It produced a really fruity beer. I didn't get back to that yeast, so I don't still have it. I am trying again with a hibiscus flower.

 

[FunkedOut]

I may not even get alcohol from this.
Anyway to tell is it’s yeast or bacteria?

It’s done making bubbles, while the second one hasn’t started yet.
It also dropped clear again; real quickly.

Smells good. I’m a bit scared to take a swig.
What are my chances of getting hurt here?

I’m starting to feel like putting this stuff in contact with any of my brew stuff is a bad idea.

 

[FunkedOut]

Here’s a pic from yesterday, when I first noticed activity.

 

[RPh_Guy]

Fermentation means you have yeast (with or without bacteria), and alcohol as a byproduct.

The one that fermented is ok to sample.

For bottling I would recommend taking gravity readings at least 3-4 weeks apart to make sure it's stable.

Try to minimize head space or you may end up with vinegar.

 

[FunkedOut]

I just took a chickenchit swig.
Taste is somewhere between Coca Cola and rancid OJ.

 

[FunkedOut]

@RPh_Guy how do you know I had fermentation?

I read that some bacteria can produce CO2.

 

[radwizard]

Heterofermentive Lacto will produce co2. What was the wort's PH before fermentation?
Personally, I wouldn't taste anything under 2% abv or over a ph of 4.4. There are some risks here.

 

[RPh_Guy]

@RPh_Guy how do you know I had fermentation?

I read that some bacteria can produce CO2.

Heterofermentive Lacto will produce co2. What was the wort's PH before fermentation?
Personally, I wouldn't taste anything under 2% abv or over a ph of 4.4. There are some risks here.

"Heterofermentative" bacteria possess the enzymatic pathways to produce alcohol and carbon dioxide (in addition to lactic acid), yes technically correct.

In reality the amount of sugar that bacteria can ferment in a closed system before becoming inhibited by the pH drop is very small (less than 4%), certainly not enough to form a krausen.

This is why we never see milk with a krausen, we don't get drunk from eating sugars/carbs even though these bacteria live in our GI tract*, and why a Google search for "heterofermentative bacteria" yields scholarly articles rather than brewing articles.

So again, an obvious fermentation means that yeast are thriving and have produced alcohol.

Radwizard is correct about the risks. However krausen means alcohol (this inhibits mold) and I think it's likely the pH dropped below or around pH 4.5 fairly quickly (this inhibits Clostridium growth) due to carbonic acid from the yeast and possibly lactic acid from any hop-tolerant LAB activity.

If you want to get into wild brewing, make some more starters like you already have (but pre-acidify to 4.0-4.5) and pick some that smell/taste good. If there's no mold growth, let the cultures age out for a couple weeks to let the dominant microbes reveal their aromas before making a decision.

Cheers!

*There is a thing called auto-brewery syndrome where you do get intoxicated from eating sugars but it's caused by yeast.

 

[FunkedOut]

Damn. Good info. Thanks for the crash course.
I didn’t measure wort ph.
Mash ph was at 5.33, 15 min into it.

I can measure the ph now. I’d bet on it being low based on taste.
I can measure the gravity, but wouldn’t bacteria lower the gravity by eating sugar and not producing alcohol?
If this is a mixed bag of bugs, no way to tell how much the ABV is, right?

The other jug never took off like the first one did; even after pouring a bit of it in.

 

[RPh_Guy]

Bacteria won't drop the gravity more than one or two points (they really don't eat much of the sugar), so you can rely on gravity reading to calculate ABV. The ABV calculations we use are approximate anyway.

FYI If you use it to ferment a batch, it's standard practice to keep separate plastic & rubber parts for the wild brews. Sanitize glass and stainless thoroughly. At least six to nine months aging is typical if you captured some Brett.

 

[65C]

brilliant thread

the one on the right looks promising

you might need to get some airlocks on or they'll pop

I don't measure ABV etc. but I do tend to start with known bacteria - I love the thinking on this and might start taking some 1 gallon second runnings for some experimental innoculations

 

[TwistedGray]

Correct me if I am wrong, but I was under the impression you should still use regular yeast post wild yeast/culture? Maybe I misunderstood something, somewhere, but I could swear you still pitch yeast at some point in the game, no?

 

[RPh_Guy]

Correct me if I am wrong, but I was under the impression you should still use regular yeast post wild yeast/culture? Maybe I misunderstood something, somewhere, but I could swear you still pitch yeast at some point in the game, no?

There's no need for a commercial strain as long as you have captured adequate wild yeast to at least reach a "normal" attenuation.

A clean strain can be added at bottling if there's been a long aging period.

 

[TwistedGray]

There's no need for a commercial strain as long as you have captured adequate wild yeast to at least reach a "normal" attenuation.

A clean strain can be added at bottling if there's been a long aging period.

So those adding a commercial yeast are doing so purely for the sake of certainty that they're eating up all the fermentables rather than rolling the dice?

 

[RPh_Guy]

So those adding a commercial yeast are doing so purely for the sake of certainty that they're eating up all the fermentables rather than rolling the dice?

Basically yes, but there's no one wanting to go through the trouble of capturing wild microbes only to pitch a commercial strain on top of them. The only time you'd *need* to add a commercial yeast to a wild fermentation is if you didn't capture a yeast strain capable of attenuation, e.g. you only captured one strain and it had a low alcohol tolerance. The chances of this happening are mostly dependant on how you inoculate your wort with wild microbes. I venture to speculate that most of the time it's not an issue.

At one end of the spectrum there is a fully wild spontaneous fermentation. Stick your whole batch of wort outside and hope for the best. Potential for greatness, high risk of off-flavors. Realistically you probably won't get good results and certainly not reproducible results.

Want a "wild" fermentation without so much risk? Make wild starters and use the ones with good character. Potential to make unique and very interesting beer. Much safer approach but still not reproducible. Commercial breweries re-use barrels with nice character to achieve this effect (sometimes after a coolship inoculation).

Want interesting but semi-reproducible beer with little risk? Use commercial mixed cultures and/or bottle dregs and/or your own previous wild cultures and/or a solera method.

Want a clean sour and/or mild Brett character? Kettle sours are fast, easy and pose little risk of contaminating your equipment. 100% Brett beers can provide some interesting notes to a limited extent, also with a quick turnaround. Mixed Sacc/Brett primary may also be possible using a Brett starter. Commercial Sacc strains only.

On the opposite end of spontaneous we have regular old clean beer with no Brett or LAB. Commercial Sacc strains only.

 

[FunkedOut]

Update...
The day after my last post (March 5th), I simply poured the contents of the jug on the right into another clean empty jug. I made sure to keep the trub from making it's way into the new jug by stopping the pour early. The surface of the beer? was completely void of anything floating. Looks and smells pretty good.

Then I see a new Brulosophy podcast is available and listen in; special guest is Bootleg Biology. Coincidence? Maybe.

Anyhow, guy talks about starting a wild yeast capture bank and I check out his site and found a complete DIY walkthrough of capturing yeast, making agar petri dishes, and then isolating yeast.
I figure I already captured the wild yeast, I'd skip making the dishes by buying some on amazon for $2 a piece and proceed right to isolating a yeast strain.
http://bootlegbiology.com/diy/isolating-yeast/

Plates came in today so I set out to get a sample from the bottom of the jug with a straw. The jug was a bit swollen and let out some pressure when I opened the lid.
Smells better and better the older it gets. Still in the garage. Still 70ish.
With the straw, I kept pulling up what looked like hard flocculated yeast from the bottom of the jug.

I should have some good pics in a couple to a few days.

This option seemed like the safest way for me to feel good that no bacteria is making its way into a wort that I worked hard at brewing.
If this isolation business goes well, I think I'll start with a 1L batch on the stovetop to test out the strain.

 

[Amadeo38]

I’m liking that your username was made for this destiny of having a wild yeast adventure. Subb’d so I can learn more as things progress.

 

[TwistedGray]

Maybe I missed the point, but why not airlock instead of closing off whatever is in there from the environment?

 

[FunkedOut]

Maybe I missed the point, but why not airlock instead of closing off whatever is in there from the environment?

This is an afterthought, zero effort effort...
Until it actually took to active fermentation.
Cap was loose so it wasn’t really closed off.
Whatever is in there got in there past the loose lid.

I only tightened down the lid after transferring to secondary, because I thought fermentation was over.
I learned I was wrong when I saw it had built up pressure.

Lambic spunding if you will.
(I’m making this up as I go along)

 

[TwistedGray]

This is an afterthought, zero effort effort...
Until it actually took to active fermentation.
Cap was loose so it wasn’t really closed off.
Whatever is in there got in there past the loose lid.

I only tightened down the lid after transferring to secondary, because I thought fermentation was over.
I learned I was wrong when I saw it had built up pressure.

Lambic spunding if you will.
(I’m making this up as I go along)

So ... is there an airlock on it now, or you still capping it?

 

[RPh_Guy]

@FunkedOut What Petri dishes did you buy?

Maybe I missed the point, but why not airlock instead of closing off whatever is in there from the environment?

Our environment is full of microbes and spores... covering everything and floating around in the air.

If he's interested in isolating a single microbe from his culture it makes sense to keep new microbes from moving in there.

 

[FunkedOut]

So ... is there an airlock on it now, or you still capping it?

Still capping it. It's been building very little pressure. I check it a few days at a time to see if it's done.

@FunkedOut What Petri dishes did you buy?

https://www.amazon.com/gp/product/B0165PQST0/?tag=skimlinks_replacement-20

 

[RPh_Guy]

https://www.amazon.com/gp/product/B0165PQST0/?tag=skimlinks_replacement-20

The LB medium on those plates isn't good for yeast growth

 

[FunkedOut]

any way to modify these plates to be something other than trash for me?
what about sprinkling a little DME over the plates before streaking them?
sugar?

I guess I can wait a few days to see what I get.

 

[FunkedOut]

this one seems like the right media:
https://www.amazon.com/dp/B01LZCBCVO/?tag=skimlinks_replacement-20

 

[RPh_Guy]

any way to modify these plates to be something other than trash for me?

Any attempt to modify them would likely result in contamination.

this one seems like the right medium:
https://www.amazon.com/dp/B01LZCBCVO/?tag=skimlinks_replacement-20

Yep, those should work!

 

[FunkedOut]

Here’s what I have 3 days later in the ‘wrong’ petri dish:

Needless to say, I have no idea what I’m doing here.
Now for some unqualified opinions...

Looks like I have quite a few single yeast colonies here. And they all look like they’re the same strain.
No bacteria growth yet.
Thinking letting these bloom for a couple more days to see how the develop is a good idea.

Otherwise, I think I’m ready to grab a white chunk and put it in a small (10mL) steril starter!

Note:
The ‘wrong’ dish is ‘wrong’ because it has media that is better suited to growing bacteria than growing yeast.
The ‘right’ dish is just the opposite.

 

[RPh_Guy]

Looks like you're about ready to grab a microscope and do some gram stains

 

[FunkedOut]

Looks like you're about ready to grab a microscope and do some gram stains

OK. Appreciate the nudge towards continued education.
But, I'm not going to buy a microscope and stains right now.

Not sure what your hinting at here.
Are you saying that these white dots could be bacteria?
Or just saying I need to stain to see if different islands are the same strain?

I was planning on taking the largest island and using only it to inoculate a small starter?

Would you say that I have yeast here?
I'm going to try and take a better picture with a better camera than my phone and some proper lighting...

Looking at this page of pics:
http://bootlegbiology.com/diy/microbe-portrait-gallery/
What I have here could be brett, could be pedio, or could be yeast.

 

[RPh_Guy]

Sorry I was trying to be funny. Fail.

Almost anything that's growing might look like a white dot on the agar to an untrained eye (mine included). ... But at least it looks like you have some nice individual colonies of SOMETHING growing, which means your streaking technique was good enough and the plate wasn't contaminated in the process. Some plates I've seen look like a friggin mess.

Your plan sounds good to me. If it ferments you'll know it's yeast of some kind.
If it's yeast it could even just be the last commercial strain you pitched still floating around in your brewing area since that's where you captured it, ...who knows?

I can't find the quote now but I heard from someone at one of the major yeast labs that only around 10% of wild yeast strains can make decent beer on their own.
If that's true, you'd need a combination of persistence and luck to find a good one Don't feel bad if the first one is a bust.

Cheers

 

[TwistedGray]

I can't find the quote now but I heard from someone at one of the major yeast labs that only around 10% of wild yeast strains can make decent beer on their own.

I imagine you're better off being in the woods far away from population? Like, I wonder about getting it in time to go camping and dropping a container in the the woods for the weekend or next to a non inhabited coastal area.

 

[FunkedOut]

I live in an area not close to dense population, in a coastal area, just miles outside of a 140,000 acre wildlife refuge.

 

[MizzouFermentationScience]

$0.02 from a wild yeast enthusiast.

Remember that beer was invented before we knew yeast existed- the process is selective for S.c. The take away being that if it’s fermenting, you’ve got beer.

As a wild yeast enthusiast, I don’t believe in wild yeast... my guess is that a commercial strain or progeny thereof is doing the work. Not that this is a bad thing, yeast culture will “evolve” into something unique over time.

Without proper lab equipment, I’d say home brew microbiology is a waste of time. It’s very hard to keep cultures from getting contaminated, there is a lot of very expensive research that had been ruined by contamination. Rather than plate the yeast, I’d keep feeding it with S.c. crack (wort).

Also, you can clean equipment well enough to go back and forth between Brett/wild and normal. Use oxiclean and be thorough, it produces H2O2 which is a sanitizer on top of its cleaning ability. Still sanitize as normal, but it’s s good way to get double duty from cleaning. Bleach is great too if you want to risk it.

 

[RPh_Guy]

$0.02 from a wild yeast enthusiast.

Remember that beer was invented before we knew yeast existed- the process is selective for S.c. The take away being that if it’s fermenting, you’ve got beer.

As a wild yeast enthusiast, I don’t believe in wild yeast... my guess is that a commercial strain or progeny thereof is doing the work. Not that this is a bad thing, yeast culture will “evolve” into something unique over time.

Without proper lab equipment, I’d say home brew microbiology is a waste of time. It’s very hard to keep cultures from getting contaminated, there is a lot of very expensive research that had been ruined by contamination. Rather than plate the yeast, I’d keep feeding it with S.c. crack (wort).

Also, you can clean equipment well enough to go back and forth between Brett/wild and normal. Use oxiclean and be thorough, it produces H2O2 which is a sanitizer on top of its cleaning ability. Still sanitize as normal, but it’s s good way to get double duty from cleaning. Bleach is great too if you want to risk it.

I generally agree.

However if he wants a "clean" beer with "wild" yeast (be it Sacc or Brett) he does need to isolate it at least once. Also, starting from a single cell should significantly reduce generic drift so the resulting beer should be more consistent over multiple batches.
Then there is the cool factor of taming your own single-celled organism to make a delicious alcoholic drink ...much like we go through the trouble and expense to make our own beer rather than just buying it.

Probably most people dealing with wild microbes want sour beer. I agree that attempting to isolate and maintain a single culture is difficult and unnecessary for mixed culture fermentation.

 

[FunkedOut]

...Remember that beer was invented before we knew yeast existed...

...As a wild yeast enthusiast, I don’t believe in wild yeast...

Those 2 pennies don't jive in my mind.
I find it easier to get behind the I don't believe in commercial yeast mindset.
All the commercial guys have is wild yeast that's been captured, isolated and propagated.
I'm not sure what you're telling me here, but I'm listening...

I'm not saying I have a revolutionary future award winner here. It might be pure trash, but I am willing to explore this a bit and find out.
I feel like I have gotten very lucky this far, capturing a bug that produced fermentation that made a decent smelling and tasting beer.
Then streaking on a plate that is well suited to bacteria and not growing any?
OK, that one's a maybe.
On to the next step to keep on pushing my luck.

Here's a better pic of the plate:

I made up 5mL of 1.020 wort using distilled water and Pilsen Light DME.
Made the wort in this sanitized bottle I had from hot sauce adventures, then boiled the wort, uncovered in the microwave with 5 second blasts.
As soon as I saw a boil over starting, I hit cancel, put the sanitized cap on, and shook it a bit to do my best to sterilize the cap.

Once it cooled, I grabbed 3 isolated colonies with a sterilized loop and swirled them into the bottle, gave it a shake and back to the waiting game.

 

[RPh_Guy]

I suggest sticking with one colony next time. Those colonies could be completely different species for all we know at this point.

 

[FunkedOut]

sho nuff.
I read something about genetic diversity on braukaiser and it got the better of me.
Most sources say to stick with only one colony.

I've got another little bottle like that.
Think I'll run this one both ways.

 

[RPh_Guy]

Next step is a PCR and some electrophoresis gels to determine whether they actually were the same.

(Joking)
But seriously homebrewers have done it.

 

[Calaeb]

This is cool, interested to see what happens next!