Collecting Wild Yeast

[feldmann]

I had some left over wort after brewing on Saturday so I decided to try an experiment in collecting wild yeast. On Saturday I put some wort in a mason jar and covered the top with plastic wrap that I pocked holes in to keep any critters out. I let it sit outside on a window sill for two days and then covered it with the proper lid and but it in a kitchen cupboard. At this point in time it appears like there's something growing inside and it has a very very faint sour smell to it so I'm hoping I caught something.

If I had done some more research BEFORE doing the experiment I would have done a few things differently like made a few different samples, put then in different places and had a control that was sealed inside right from the start. I also read that adding citric acid helps keep away some bacteria and mold.

Has anyone ever tried anything like this before?

http://imgur.com/KAeh1hH

http://imgur.com/1NanFQL

[blisster]

Sounds interesting, I'm curious to see how it turns out... How much leftover wort did you have?

[jamie_savoie]

This is really cool

Actually, this is a project I have lined up with the CCNB in GF for the summer.  We want to capture and isolate wild yeast and experiment with it.

I'm no expert on wild yeast but I know lambic producers don't brew in the summers because there are too much undesirable bacteria in the air. Usually they only brew between October and May.

If you had good amount of hops maybe this will help you because as you know hops have anti-bacteria properties and can inhibit lactobacillus growth.

I would step it up to a gallon and forget it for 6 months+ while tasting small samples along the way.  If it tastes like vomit, dump it; if it tastes good then make a bigger batch!

When my home yeast lab is going to be ready and when I'll know how to properly isolate yeast I could try to "cleanup" your wild yeast   (well if it taste good lol)

[feldmann]

I had more wort but I threw it out before I really planned out what I was doing. The wort I used wasn't hopped yet but I've read a bunch of places the benefits of using hopped wort.

I'd be worried about the wort freezing outside from October to May.

[Chris Craig]

I had more wort but I threw it out before I really planned out what I was doing. The wort I used wasn't hopped yet but I've read a bunch of places the benefits of using hopped wort.

I'd be worried about the wort freezing outside from October to May.

You should freeze extra wort for use in starters.  Way cheaper than using DME.

[feldmann]

I had more wort but I threw it out before I really planned out what I was doing. The wort I used wasn't hopped yet but I've read a bunch of places the benefits of using hopped wort.

I'd be worried about the wort freezing outside from October to May.

You should freeze extra wort for use in starters.  Way cheaper than using DME.

Never thought of that! Thanks!

[Bellick]

Its a good start, but you won't be able to isolate wild yeast that way, its a good plan to possibly catch some for isolation though. Without an early inoculation of yeast any wort left exposed will be quickly loaded with bacteria. You'll need to sample then plate out that wort on an agar that selects for yeast to ensure no bacteria grow, which isn't all that hard and you can do at home with some basic supplies.

[feldmann]

Its a good start, but you won't be able to isolate wild yeast that way, its a good plan to possibly catch some for isolation though. Without an early inoculation of yeast any wort left exposed will be quickly loaded with bacteria. You'll need to sample then plate out that wort on an agar that selects for yeast to ensure no bacteria grow, which isn't all that hard and you can do at home with some basic supplies.

http://eurekabrewing.wordpress.com/2012/08/24/yeast-banking-2-agar-plates/

Is this the sort of materials and technique I'm looking for? I read on home brew talk that a few guys were using paper clips as inoculating loops.

Also, an update. There is now clear activity inside the jar:

[Bellick]

Yes those are exactly what you are looking for, a paper-clip could work, as long as its sterilized under a flame. I can't find anything in my notes specific to inhibiting just bacteria - the main concern in a brewery is inhibiting brewers yeast from samples so we know if anything else - contamination wise- is in there. What you'll have to do is steak a plate from the wort; let it grow up, and identify a yeast colony from its shape/texture/color; sample only that colony with the loop; steak that to another plate to isolate that micro-organism, grow it, then take a sample from there to grow up a starter. Then you will have ONLY that micro-organism growing in the starter wort.

Your wort looks promising, but a concern may be how you prepared it. There is a chance you may have inadvertently gotten some brewers yeast in there, especially if you prepared it in your usual brewing area. This is where a yeast inhibiting plate would come in handy.

[jamie_savoie]

Nice brett pellicle
How's the smell?

I highly suggest reading the Yeast book by Chris White and Jamil if you want to get into this kind of stuff it has tones of informations!  @Chris Craig has it for sale

[feldmann]

Nice brett pellicle
How's the smell?

I highly suggest reading the Yeast book by Chris White and Jamil if you want to get into this kind of stuff it has tones of informations!  @Chris Craig has it for sale

At first it smelled sort of like a strange yeasty, malty sourdough bread. Now it smells really funky and wild, not like anything I've really smelled before.

[feldmann]

Does anyone know where I could find petri dishes or similar lab equipment in the local area? All of the places I've found online either only offer bulk orders or charge ridiculous shipping.

Also a small update:





Activity appears to have slowed down, not as much on top but theres a lot more sediment on the bottom.

[jdueck]

BAP Equipment might have something, if not they can order it for you

[jamie_savoie]

I have some petri dishes, how many you want?

[feldmann]

Probably just 3 or 4 please