Harvested "wild" yeast resulted into... normal beer

[xben]

Hi,

I harvested wild yeast from my backyard, following the article from the homepage, with success.

I built a starter and brewed with it (all-grain), from 1.060 down to 1.006 after 2 weeks.

My only concern is that... it tastes like if I used US-05 or some other commercial yeast. I was expecting something funky, as it produced a strong vinegar taste during the first days in the bucket. For sure it is not carbonated yet or may be not finished too.

Am I lucky or not?

 

[brewbama]

Using wild yeast is a crap shoot. It could taste great or taste like cow ass. Maybe you hit gold.

 

[kh54s10]

I would say you are lucky. I think you could just as easily have captured a yeast that would make a terrible beer. US-05 makes great beer. I would not judge the flavor until it has been aged a bit (bottle conditioned or in the keg for a week or so) I tasted one once and said this one is not so good, after conditioning, it was very good... I have also had a couple that I tasted and said this one is going to be great, when finished it was just good. I have tried twice, both were OK, and both were different from what I usually use. They made good beers, but nothing super.

 

[xben]

I'll wait until the next keg is empty and see how it turns..

 

[couchsending]

Chances are you actually harvested Us05. It’s virtually impossible that an actual “wild” yeast is POF-.

 

[xben]

I used cleaned and sanitized mason jars that have never been in contact with any yeast strains ever.

 

[ccous]

Primary fermentation with wild yeast can come off as pretty clean initially. Of course, that will change over the course of time, from a few weeks to months depending on a number of factors

 

[couchsending]

I used cleaned and sanitized mason jars that have never been in contact with any yeast strains ever.

Doesn’t mean a brewing yeast wasn’t in the air.. is the yeast you harvested phenolic?

 

[RPh_Guy]

It’s virtually impossible that an actual “wild” yeast is POF-.

What kind of percentage are we talking? You have a source for that?

 

[xben]

Doesn’t mean a brewing yeast wasn’t in the air.. is the yeast you harvested phenolic?

It is phenolic but not unpleasant

 

[couchsending]

What kind of percentage are we talking? You have a source for that?

Just the first thing I came to, I’lll look for more info.


http://allaboutbeer.com/article/the-family-tree-of-yeast/

Wild yeasts are POF+, but the report indicates that medieval brewers must have selected POF- yeast early on, Verstrepen explains, because they were most likely the starting point for domestication. “The most intriguing questions we cannot answer yet is how they did this,” he says. Every fermentation will contain a few cells that turn POF- because of spontaneous mutation, but those would “only be one or a few cells in a gazillion POF+ cells.” Yet it happened for both the Beer 1 and Beer 2 families.

“The POF+ yeasts used for some beers seem to have regained their POF characteristics, rather than never losing them, likely because they crossed with a POF+ yeast, or at least received some part of DNA of one,” he says.


The fact that the “wild” yeast you harvested went from 1.060 to 1.006 in two weeks is equally as nuts. Finding a yeast in the wild that can ferment the complex sugars from wort is almost as crazy as finding one that’s POF- although it sounds like yours does produce phenols.

A wild yeast that ferments beer and that fast is incredibly rare. If it is in fact wild I’d go buy a lottery ticket.

 

[kh54s10]

Chances are you actually harvested Us05. It’s virtually impossible that an actual “wild” yeast is POF-.

What is POF?

I have (I think) harvested wild yeast twice. Once by putting a rose blossom in wort, and once the same with a hibiscus flower. Both fermented my beer. Not as low as a commercial yeast would have and both were different than any yeast I have used. And I have used a lot of different yeasts.

I don't know what they were, but they made fairly decent beers.

 

[couchsending]

What is POF?

I have (I think) harvested wild yeast twice. Once by putting a rose blossom in wort, and once the same with a hibiscus flower. Both fermented my beer. Not as low as a commercial yeast would have and both were different than any yeast I have used. And I have used a lot of different yeasts.

I don't know what they were, but they made fairly decent beers.

POF stands for Phenolic Off Flavor.

Yeast are either POF+ (they produce phenols) or POF- (they don’t). Some domesticated brewing yeasts evolved over time to be POF-.

 

[RPh_Guy]

Finding a yeast in the wild that can ferment the complex sugars from wort is almost as crazy as finding one that’s POF- although it sounds like yours does produce phenols.

This is definitely not true. Lots of wild yeast can ferment maltose.

 

[xben]

I will bottle condition some of the batch to see how it turns in the next few months. Maybe there was some commercial yeast in the air while I did my dme-wort in the kitchen but I don't brew my batches there. I don't open any bottles there too (kegs are in the basement). I plan to keg/bottle in the next 2-3 weeks, I will let you know if the taste/gravity changed.

 

[couchsending]

This is definitely not true. Lots of wild yeast can ferment maltose.

1.006 from 1.060 means more than maltose.

And yes they do exist but I would say they’re rather hard to find. You’re much much more likely not to find one.

 

[RPh_Guy]

1.006 from 1.060 means more than maltose.

And yes they do exist but I would say they’re rather hard to find. You’re much much more likely not to find one.

Fair enough, maltose and maltotriose.
What is "rather hard to find" as a percentage?

It's a numbers game. Suppose one hundred different yeast strains land in the wort during collection. Even if the chance of each individual strain fermenting malt sugars is only 1%, the odds of at least one of the 100 strains fermenting malt sugars is 63%, quite high.

That's the magic of mixed cultures.

 

[brownni5]

Chances are you actually harvested Us05. It’s virtually impossible that an actual “wild” yeast is POF-.

Virtually? Maybe. Could also be a temp thing. S. arlintonensis from Bootleg Biology is a wild harvested yeast that's really clean at lowish ale temps.

 

[couchsending]

Fair enough, maltose and maltotriose.
What is "rather hard to find" as a percentage?

It's a numbers game. Suppose one hundred different yeast strains land in the wort during collection. Even if the chance of each individual strain fermenting malt sugars is only 1%, the odds of at least one of the 100 strains fermenting malt sugars is 63%, quite high.

That's the magic of mixed cultures.

I have no idea what the “percentage”
Is exactly? Have you heard the guys from bootleg or Matthew Bochman speak about wild yeast they’ve tested. They make it sound like there are so few yeasts that they test that will fully ferment beer.

 

[Miraculix]

Literally everybody who has experience in wild fermentation warns about bottling too early because usually the mix of wild yeast being collected is at least slightly diastaticus. So by all means, chances for a single collected strain being able to ferment complex sugars might be low, but we are talking about thousands simultaneous strains of which quite a few will be able to produce some decent enzymes to chop starch and longer sugars into pieces.

 

[RPh_Guy]

Right, with single isolates the chance is relatively low. But when you collect a whole bunch of stains, the odds of getting a strain with a high attenuation increases drastically.

 

[couchsending]

That much attenuation in 2 weeks? Doubtful

 

[Dland]

Not interested in wild yeasts at this time, but have gone from 1.060 to 1.008 in two weeks with US-05. Lower mash temp of course.

 

[RPh_Guy]

That much attenuation in 2 weeks? Doubtful

He built up a starter

 

[Miraculix]

Wild fermentations can be really quick with a starter and also bone dry. All my wild stuff fermented close to 1.0, so I would say this 1.006 in two weeks with a starter is perfectly possible. Although I never had a clean tasting wild ferment, but this doesn't mean that it's not possible to get one. Maybe there is a bit of commercial brewing yeast involved, maybe not.

 

[Kenmoron]

I am currently playing with some wild yeast I harvested off some raspberries in my backyard. I've been trying to sequentially isolate the stronger, better beer-brewing strains. Here is what I've done:

wort 1: 1.040 pre-acidified to about 4.5, pitched raspberries and let ferment x2 weeks. Unknown FG. Lots of funk and phenols but not entirely unpleasant.

wort 2: 1.044 pre-acidified to about 4.5, pitched the yeast cake from wort 1 into this wort after decanting. Fermented x2 weeks. Final gravity 1.011 but unsure if this was stable or not as I only checked once. Phenols were still present but not as harsh...a bit more fruity ester character.

wort 3: 1.040 with vodka added to make 4% abv. Pitched the yeast cake from wort 2 after decanting. I wanted to kill off any weak strains that couldn't tolerate alcohol. After 48 hrs I krausened the top and pitched that into a starter. I wanted to get all of that old trub/dead cell material separated. Planning on pitching my starter into a full batch tomorrow.

It seems like I had some decent attenuation for a 2 week ferment as well (even without a "starter"). As mentioned, these wild yeasts are usually mixtures of a TON of different strains with various mutations. I don't think it's too crazy to see good attenuation early on. However, the fairly clean fermentation profile is a bit rare. What wasn't mentioned was the fermentation temperature, which can have a significant effect. I will likely plan on spitting up my wild ferment and testing out at different temp ranges to see how clean or 'wild' it can be.

 

[Miraculix]

I am currently playing with some wild yeast I harvested off some raspberries in my backyard. I've been trying to sequentially isolate the stronger, better beer-brewing strains. Here is what I've done:

wort 1: 1.040 pre-acidified to about 4.5, pitched raspberries and let ferment x2 weeks. Unknown FG. Lots of funk and phenols but not entirely unpleasant.

wort 2: 1.044 pre-acidified to about 4.5, pitched the yeast cake from wort 1 into this wort after decanting. Fermented x2 weeks. Final gravity 1.011 but unsure if this was stable or not as I only checked once. Phenols were still present but not as harsh...a bit more fruity ester character.

wort 3: 1.040 with vodka added to make 4% abv. Added wort to the yeast cake from wort 2 after decanting. I wanted to kill off any weak strains that couldn't tolerate alcohol. After 48 hrs I krausened the top and pitched that into a starter. I wanted to get all of that old trub/dead cell material separated. Planning on pitching my starter into a full batch tomorrow.

It seems like I had some decent attenuation for a 2 week ferment as well (even without a "starter"). As mentioned, these wild yeasts are usually mixtures of a TON of different strains with various mutations. I don't think it's too crazy to see good attenuation early on. However, the fairly clean fermentation profile is a bit rare. What wasn't mentioned was the fermentation temperature, which can have a significant effect. I will likely plan on spitting up my wild ferment and testing out at different temp ranges to see how clean or 'wild' it can be.

You do not kill yeast with higher alcohol percentages, they go dormant. If you bring them back into lower alcohol environment they wake up and start working and multyplying again.

You need to do this aga plate method to isolate strains... but that takes time and effort... and skills.

 

[Kenmoron]

You do not kill yeast with higher alcohol percentages, they go dormant. If you bring them back into lower alcohol environment they wake up and start working and multyplying again.

You need to do this aga plate method to isolate strains... but that takes time and effort... and skills.

Sorry, "kill off" may not have been the appropriate phrase. Was just trying to simplify my intent. However, letting the more alcohol-tolerant strains feed and multiply while the less tolerant strains are dormant will substantially reduce their numbers and hopefully result in an almost imperceptible expression.

To note...yeast mortality increases as you increase toxins. Alcohol is a toxin to yeast and those that are inherently more susceptible may in fact die due to stress. In terms of brewing yeast dormancy, we often think of the yeast as just sleeping because these are domesticated strains and have been exposed to more and more alcohol over time, developing mutations to help them live and thrive in that environment. Many strains are much more susceptible, especially wild strains.

I had thought about agar plating, but was afraid of losing some of that wild character so preferred to keep it as a mixed culture. The downfall with plating is that you may end up grabbing a strain that fails to have some of the character you were hoping for (less attenuative, more/less phenols or esters, etc.). I might plate in the future but wanted to get a good idea of what the mixture brings to the table first.

 

[RPh_Guy]

@Kenmoron Nice job, very smart!

A have several wild cultures in progress. My plan is to keep them mixed if they have any detectable Brett characteristics. I'm leaving them for 1-2 months to make sure Brett has time to develop. Otherwise if they have nice character I will isolate single strains, so I don't have to worry about over carbonation in bottles.

Cheers

 

[Kenmoron]

Thanks @RPh_Guy! From what I've read it's extremely rare to capture Brett in the wild. I've essentially ruled it out as a non-factor. Hopefully that holds true when I decide to bottle so I don't end up with bombs haha. If you do happen to get Brett, it likely won't matter how many cells, as long as you get one it's an all-you-can-eat buffet!

per Milk The Funk Wiki:
"Brettanomyces is notoriously difficult to bioprospect from the wild. While it has been alleged by many that the natural environment for Brettanomyces is the skins of fruit or the bodies of insects, it wasn't until 2007 that science was able to show that Brettanomyces survives on the skins of grapes, although it does so in a very low population and a possibly "viable but not culturable" state."

 

[Miraculix]

Thanks @RPh_Guy! From what I've read it's extremely rare to capture Brett in the wild. I've essentially ruled it out as a non-factor. Hopefully that holds true when I decide to bottle so I don't end up with bombs haha. If you do happen to get Brett, it likely won't matter how many cells, as long as you get one it's an all-you-can-eat buffet!

I had the pleasure at least twice. Just judged on the pellicle and the barnyard taste, of course. I don't think that it is that rare tbh.

 

[RPh_Guy]

I think the chance of capturing Brett greatly depends on your technique and the sources you use to harvest.
I've heard anecdotes of people finding it very frequently (confirmed via isolation and identification). Personally, one of my batches of 2018 unpasteurized cider definitely had Brett character (the first year I used unpasteurized juice).

I believe MTF says it's rare because the microbiologist(s) sharing their experience use a rapid propagation technique to get single isolates (aerobic, couple days for each step) and its not suitable for isolating Brett. Somewhere on the wiki or FB group they explain this further.

Even if you don't have Brett specifically in your mixed culture, there's still danger of over-carbonation from any number of other yeast species that are slower but more highly attenuating than the fast primary strain(s). I would be very cautious.

Anecdotally, I've even had wild cider over-attenuate several months later... despite pitching yeast, using an aggressive nutrient schedule (TOSNA), an utter lack of dextrins obviously, and letting it ferment to an apparently stable low FG over a few weeks.

 

[xben]

After 2 more months, it won 2 more points (1.004). I decided to keg and bottle.