Howto: Capture Wild Yeast

While it is true that the insects are a more sure-fire way of innoculating wort with wild yeast, they also carry other microbes that are less desireable for beer, such as acetobacteria, which are the microbes used in making vinegar, the best way to ensure the capture of wild yeasts and microbes that are desireable for brewing is to have a semi-fine mesh to keep fruit flies out but allow some particulate and spores in.

Definitely true, perhaps especially for fruit flies - it's almost as though their legs were made-to-order for the purpose of spreading acetobacter, almost as high a priority for them to be reproducing their own kind.

...maggot-makers... I hate 'em....

This thread has inspired me to try and catch some wild yeast near me. I wonder what kind of yeasties live in the big citrus groves near where I live. Or even out in the desert, like at Joshua Tree. The latter may have to wait for autumn, but the former I may be able to explore. I wonder if I can inoculate some sterile wort with a few picked orange blossoms off of a tree (they really frown upon picking oranges at the State Historic Park I am planning on getting some yeast from).

You could always put some wort in a shallow container and dip an orange on the tree in the wort and then transfer it to a different container when you get home.

Hey guys, long time reader, but this thread has inspired me to finally sign up.
My question is related to anti-bacterial substances. In theory wouldn't common anti-bacterial like penicillin protect the mini-wort from infection? Or would it kill off yeasts as well? I also have some oregano oil, which is supposed to be a natural anti bacterial. Would this help? Or just cause problems?

Sure, people use streptomycin at 40 ug/mL or chloramphenicol at 50-100 ug/mL to catch yeast. Probably want to invest in a pipette to get the dosage right.

Antibiotics work by messing up some process that only bacteria do, leaving humans and yeast alive.

Thanks for the info. Also, will lactic acid hurt the culture if I want to raise the acidity? I don't have any lemon juice at the moment. I'm going to try culturing the yeast from juniper berries and sap + unpasteurized natural honey.

No, yeast do fine with lactic acid, and citric and acetic. If you add vinegar or lemon juice from a bottle, though, check that it doesn't contain other preservatives, which might inhibit yeast growth.

Honey contains lots of Zygosaccharomyces (and other yeasts) but the osmolarity is too high for Saccharomyces. Think about this -- your brewing yeast have a hard time living in a very sweet wort, so imagine how much more difficult life will be for them in honey. They just can't cut it there.

Also, the bloom on the surface of juniper berries is not yeast -- nor is the white stuff on grapes. These are just white powdery substances that plants make. You're as likely to find yeast on juniper as you are any other fruit with a thin skin. Try grapes or raisins (since they're very sweet) for a first pass.

I think the oregano oil sounded interesting. Thyme is supposed to be antibacterial as well. But of course the old standby hops do a good job in this department!

Subscribed.

I am going to try this and I have the perfect beer to do so.

I brewed a Kentucky Common that I named Goat Holler Brown, for a street in Southern Indiana near where my fiancee grew up. When we go down to visit her parents next week, I am going to bring a jar and collect some wild Goat Holler Rd. yeast. This should be a winner.

drummstikk said:

No, yeast do fine with lactic acid, and citric and acetic. If you add vinegar or lemon juice from a bottle, though, check that it doesn't contain other preservatives, which might inhibit yeast growth.

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The RealLemon stuff (and similar brands) has preservatives so you will want to avoid using it. I don't think there is any way to denature them or boil it out.

Generic white vinegar should be distilled vinegar dilluted with water and nothing else. I have used white vinegar in a brett starter with no ill effect. Other forms of vinegar (e.g. unfiltered vinegar, balsamic vinegar and other flavors of vinegar) may have preservatives.

Alright, it's been two weeks, and I've noticed something pretty crazy.
Apparently, (no idea how this happened) the juniper berries, which were floating on top, have formed a jelly that covers the top of my starter jar. This jelly has started growing a variety of different things: I see a few spots of mold, but also a couple interesting cultures that resemble yeast cells.
So WTF, did the vinegar (distilled white) react with the juniper berries? Did I inadvertently create an agar-like petri-dish culture?
All in all, it's pretty exciting.

BenjaminBier said:

howdy all, i also gave capturing wild yeast a try. I stuck a cup of apple juice in a mason jar out in the garden for about 6 hours, brought it inside and covered with foil, and let it sit on top of the fridge for about 10 days.

It started getting some nice bubbling and a sediment formed, smelled like tart apples. I pulled off the liquid with a turkey baster and added a cup of wort to the jar, it developed a nice looking krausen and started smelling estery and phenolic. Added another cup of wort, let that ferment for a few days, started smelling really really estery, lots of fruit and pepper, added another bit of wort to it and it started going fruity, peppery AND bubblegummy.

So i brewed up a batch of german hefeweizen and pitched about a liter of this starter, it took off and was cranking out some major odors. think rhino farts mixed with sour fruit.

Now i'm about 4 days in and the odors have died down, it's smelling very peppery and bubblegummy, a little tart. I had reserved a little bit of the started and built it up again, it looks like it's mostly fermented out today so I had a taste, very strong but pleasant yeast character.

woot!

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how did this turn out?

Ridcully123 said:

Alright, it's been two weeks, and I've noticed something pretty crazy.
Apparently, (no idea how this happened) the juniper berries, which were floating on top, have formed a jelly that covers the top of my starter jar. This jelly has started growing a variety of different things: I see a few spots of mold, but also a couple interesting cultures that resemble yeast cells.
So WTF, did the vinegar (distilled white) react with the juniper berries? Did I inadvertently create an agar-like petri-dish culture?
All in all, it's pretty exciting.

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Are you sure it isn't acetobacter forming a mother culture?

Oldsock said:

Are you sure it isn't acetobacter forming a mother culture?

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Did some research. Doesn't look like a typical aceto culture, but, because I added the vinegar, it probably skipped the calcium corbate production and created a transparent culture.

Still interesting, but no yeast.

Well actually scrap that, even if acetobacteria has taken over, I might still have some wild yeasts. The culture on top of my jar is a "mat" of asorted organisms, yeasts as well as bacteria. Separating them though is going to be...hard.

Some lactic acid bacteria can secrete slimy substances. Lambic brewers call this getting "sick". I wouldn't worry to much about whether you have one type of bug or another. It's hard to know without a microscope and diagnostic culture media. Why don't you try diluting a little but in fresh wort and see if the mat reappears or not.

Gross question: would keeping my cup of wort on the bathroom window be unsafe because of the toilet being fairly close by? I put my cup there for a day or two but now I'm worried that maybe it's been contaminated because of flushing? (Yes I realize this was a dumb idea. It's the only good option for a window.)

Thanks!

Pugalicious said:

Gross question: would keeping my cup of wort on the bathroom window be unsafe because of the toilet being fairly close by? I put my cup there for a day or two but now I'm worried that maybe it's been contaminated because of flushing? (Yes I realize this was a dumb idea. It's the only good option for a window.)

Thanks!

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They actually did a relevant test on Mythbusters that might put you at ease. They were testing the myth that toothbrushes stored in open air in bathrooms might collect enteric bacteria from being in proximity with used, flushed toilets. For a month they exposed samples to areas all over the shop, including one placed directly on top of the toilet tank for maximum "exposure." The result: all the sample sites had the same count of poo-poo class bacteria, including ones that were in other rooms that weren't the shop's bathroom. Sounds like you're good to me.

DeGarre said:

I live on a 100+ year old farm, lots of unused barns, animal shelters, old attics etc that haven't been used since the 60's - should be lots of wild yeast floating around I reckon. Next time I brew I'll place some jars all over the place.

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please do... that sounds like an awesome experiment...

my wild formed a pellicle after attenuating like mad quickly...

bigbeergeek said:

how did this turn out?

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It turned out great!!! It fermented out a little slowly but it did finish around 65% attenuation. The yeast character came out nicely fruity, a bit apricotty. I used mark & tess's franziskaner hefe recipe and it matched pretty well. I'm not totally convinced the yeast is wild or if it's something from my brew closet that got loose. I'll post a picture this week when we get home from vacay.

drummstikk said:

Some lactic acid bacteria can secrete slimy substances. Lambic brewers call this getting "sick".

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Sick is actually a whole wort thing, not a layer on the top. It really isn't visible looking at the beer, the liquid just becomes viscous and stringy (after you take a sip you’ll get a little string that attaches from your lip to the glass). Only had it happen once, beer turn out great though.

Oldsock said:

Sick is actually a whole wort thing, not a layer on the top. It really isn't visible looking at the beer, the liquid just becomes viscous and stringy (after you take a sip you’ll get a little string that attaches from your lip to the glass). Only had it happen once, beer turn out great though.

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I had the same thing, fermenting this wild yeast which was 100% pure culture (checked colonies, microscope). OG was 1070, and around 1040 I could not even rack it if I wanted to (took a little out to see what was going on). It was totally viscous.

Doesn't sickness come from pedio? I'm not an expert but I recall an interview w/ Vinnie C in which he was talking about beers being sick with Belgian brewers. From what I recall, yeast wasn't the culprit, it was bacteria.

Ridcully123, if you don't think it's the entire wort getting sick, do you think you've got a layer of mold on the top that formed the mat? Or do you think what you're seeing is mold colonies on top of a yeast pellicle?

Either way, I think it would be interesting to dilute into fresh wort, let it grow for a while (a week or so), and repeat the dilution and growth a few times, to see if the mold goes away, and to see if the mat reappears.

Good luck!

mhenry41h said:

Doesn't sickness come from pedio? I'm not an expert but I recall an interview w/ Vinnie C in which he was talking about beers being sick with Belgian brewers. From what I recall, yeast wasn't the culprit, it was bacteria.

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I heard that too. I have been extremely careful though and checked under the microscope to see if it was a pure culture. I also striked a couple of times.
I will check again - if there is pedio I will kick my own ass for not working as clean as I thought I was doing, and ill be happy as well.

jaapie said:

I heard that too. I have been extremely careful though and checked under the microscope to see if it was a pure culture. I also striked a couple of times.
I will check again - if there is pedio I will kick my own ass for not working as clean as I thought I was doing, and ill be happy as well.

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You could only be so lucky as to have wild Brett and pedio! Of course, pedio without lacto might not be good. I think pedio on it's own throws an off flavor. Acetylaldehyde maybe? I really need to go a wild yeast beer. My wife's grandfather has a grape arbor and I'd like to dro a few grapes in some wort and cultivate it. Without a microscope I'm hesitant.

jaapie said:

I heard that too. I have been extremely careful though and checked under the microscope to see if it was a pure culture. I also striked a couple of times.
I will check again - if there is pedio I will kick my own ass for not working as clean as I thought I was doing, and ill be happy as well.

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Yep, Pedio is the one that creates the long chains, although I got a similar (although not as pronounced) character early on in my red wine yeast Flemish Red which I attributed to the BM45. So it is possible that it is a wild yeast that is responsible if your issue is high viscosity.

mhenry41h said:

You could only be so lucky as to have wild Brett and pedio! Of course, pedio without lacto might not be good. I think pedio on it's own throws an off flavor. Acetylaldehyde maybe?

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Pedio makes diacetyl, which is why it is often paired with Brett (which cleans it up).

bigbeergeek said:

how did this turn out?

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Here's what I wound up with.

It's a Franziskaner Hefe clone from Mark & Tess. Yeast character is lightly fruity with a dry finish, aroma is very lightly tropical fruits like kiwi or melon. the fruity-ness goes through the whole beer. Over all the flavor reminds me of an english ale yeast with german hefe malts. It's really drinkable, almost all gone now. The carbonation is pretty intense even though the SG was stable for two weeks before bottling. This shot is after letting it settle a bit and additional pouring.

BenjaminBier said:

Here's what I wound up with.

It's a Franziskaner Hefe clone from Mark & Tess. Yeast character is lightly fruity with a dry finish, aroma is very lightly tropical fruits like kiwi or melon. the fruity-ness goes through the whole beer. Over all the flavor reminds me of an english ale yeast with german hefe malts. It's really drinkable, almost all gone now. The carbonation is pretty intense even though the SG was stable for two weeks before bottling. This shot is after letting it settle a bit and additional pouring.

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Looks beautiful and tasty.....congrats.

Oldsock said:

Yep, Pedio is the one that creates the long chains, although I got a similar (although not as pronounced) character early on in my red wine yeast Flemish Red which I attributed to the BM45. So it is possible that it is a wild yeast that is responsible if your issue is high viscosity.

Pedio makes diacetyl, which is why it is often paired with Brett (which cleans it up).

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That's it! I knew Pedio needed something to clean it up. I just couldn't recall what the compound was and which critter fixes it!

Maybe this has already been answered, but is it neccessary to use DME? Unfortunately I have zero funds for that purchase, and I was wondering if I cuold use either honey or sugar. Thanks!


-Kingboomer

kingboomer said:

Maybe this has already been answered, but is it neccessary to use DME? Unfortunately I have zero funds for that purchase, and I was wondering if I cuold use either honey or sugar. Thanks!


-Kingboomer

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Simple sugars are not a great option for growing microbes that you want to ferment the larger sugars in wort. You could make a nano-mash with some pale malt, pull the grains, and give it a quick boil. Good luck!

Raw honey can already be a good source of wild brewing yeast, thats what I've got fermenting my sour currently.

Sounds great guys, thanks for the input! I was actually considering useing honey with some chopped up raisins and maybe a bit of boiled bread yeast for nutrients. Does this sound feasible?


-Kingboomer

I gave it try last night, leaving out a measly little 6 oz solution of water and DME in an uncovered jar at a concentration of around 1.030. It's been hot here, but in the 70's at night. This afternoon I spied it on the back porch and remembered I had left it the night before. Checked it and something has definitely happened. Some bubbles on the edges of the liquid and some white matter suspended in the liquid. At first I thought it was the DME in suspension but not so sure. Smells like sourdough bread.

I made up a half gallon solution with DME at about 1.030 again and dumped in the 6 oz's from last night. A few hours later and its starting to smell like diacetyl. Still more whispy white clumps in suspension. I really don't think its undissolved DME but maybe I'm wrong. Overnight should have been long enough to catch some yeasties. Hopefully there's nothing too nasty in there and it will be beer by the end of the week. Hoping to have a wild saison by the fall.

I wonder what mid-atlantic yeast are like? Probably will end up with a nice wet dog flavor. :cross:

Binkman, just avoid the Jersey wild yeast...lol...could taste like armpit!

mhenry41h said:

Binkman, just avoid the Jersey wild yeast...lol...could taste like armpit!

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I moved from Boston to Baltimore about five years ago. About an hour south of NY I smelled a terrible smell, assumed it was my flatulent dog and rolled down the window. The smell got worse. North Jersey smelled like a dog's ass that day.

Well, I just finished my attempt at capturing some wild yeast based on the OP's direction and the Lambic book... Living in Phoenix, opening a window is really not an option when it's 108 F outside, so I just decided to leave them out for the entire two weeks in the backyard, covered with cheesecloth of course. I did two different 1.030 worts, one with 6 PH water and one with 2.5 PH water (have a water ionizer), as I was sure that the 2.5 PH would have a lot better of a chance to fend off various bacterias. This did happen - after a week the 6 PH was covered in a pellicle and the 2.5 PH smelled sweet and good.

Unforuntately, the heat evaporated away most of the liquid, so I reconstituted each with their respective PH waters and left them for another week. I was pretty excited with the 2.5 PH water as it smelled good and had what looked like yeast sediment at the bottom, so I decided to make a starter and pitch it in there. I had what looked like krausen within the first two days and then on day 3 or so, I noticed some white floaties and now have some large white chunks of what looks like hairy mold, so guess I got some bacteria that I may not want.

So, the primary question is how do I know what I have and if it is Brett and I should proceed with it? The secondary is, should I just start from scratch again and maybe try the overnight process, which it seems that some of you are having success with? Lastly, could the bacterias that were slightly present in the 2.5 PH wort have been allowed to run rampant when I pitched it into the roughly 6 PH wort and should I have stuck with 2.5 PH? I have pictures of it throughout the process, except of it now and can take one and post if necessary...

On another note, I still left the other 6 PH, pellicle and all, outside and if inclined may do something with it. Thanks.

Hi keesimps,

Sounds interesting! It is very tough (impossible) without a scope and different types of media to know what you've got. The exception is mold, which produces hairy and fuzzy things. (bacteria are not fuzzy) One diagnostic thought -- oxygen-loving bugs form pellicles. So you've got some oxidative yeast/bacteria in the 6 pH wort. That is consistent with Brett, but there are hundreds of yeast genera that would also fit the description. If the alcohol content is high and you still have a pellicle, then you can begin narrowing down the field.

Another thing -- water is not a great buffer, but wort is. So if you add an acid to pure water, dropping its pH to 6 or 2.5, the pH will be totally different once you use that water in a mash, or dilute that water into a concentrated wort.

A few more things -- the net probably isn't doing you any favors -- insects are a great source of wild yeast and bacteria. Also, a control will help you know which bugs are coming from the great outdoors and which came from your brewery. Just make some wort, put it outside along with everything else, but never open it for inoculation.

If you want to make a lambic, it seems like these are both off to a good start. I would just scrape the mold out and let them sit for a year.

If you want to isolate a brewing yeast, I would propagate the sediment into fresh wort and let it ferment for a week or two, repeating that 2-3 times. You may find that the beer you get starts tasting more and more pure. You could also try top-cropping any krausen you get, which will speed things up, and possibly be enriched with the bugs you want. If you want to make agar plates (only requires a pressure cooker) you can isolate single yeast colonies, too.

I hope that is helpful.

drummstikk said:

Hi keesimps,

Sounds interesting! It is very tough (impossible) without a scope and different types of media to know what you've got. The exception is mold, which produces hairy and fuzzy things. (bacteria are not fuzzy) One diagnostic thought -- oxygen-loving bugs form pellicles. So you've got some oxidative yeast/bacteria in the 6 pH wort. That is consistent with Brett, but there are hundreds of yeast genera that would also fit the description. If the alcohol content is high and you still have a pellicle, then you can begin narrowing down the field.

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I want to also chime in, hairy things are not always bad. I isolated wild yeasts and took as a control the dregs from a gueuze bottle. There was all kinds of stuff in the gueuze dreggs (as expected), and ~50% of the organisms appeared black and filamentous (hairy) on plate and in certain media. Isolated this strain and it fermented wort to zero. Some yeasts can switch between the filamentous and non-filamentous stage as well.

Of the other 3 strains I isolated from the gueuze bottle, none of them formed a pellicle, they actually sat solidly on the bottom of the fermentation vessel. The beer they made was definitely brett-like, but I did not do any strain identification besides looking at cells under a microscope. I am kind of sure they are brett though, just tasting it.

Drummstikk is right in what he says, just wanted to underline the fact that sometimes things are not like they seem when you go down the route of spontaneous/wild fermentation.

Thanks guys, that really does help! I am thinking that I will keep propagating the sediment as you noted drummstikk and see what I can get and if I get a good enough krausen may try to top crop. I am honestly not trying to get a lambic, so think that this may be a better bet.

Two more things:
1. Should I be concerned taking a gravity reading of either test batch and contaminating my hydrometer test cylinder?
2. Should I avoid tasting the 2.5 PH starter wort due to the fact of what I've got growing in it?