Intriguing yeast in a soda can: need advice ASAP

[Trail]

I had a Batman: The Brave & the Bold marathon with my kids Wednesday night, and over the course of the evening we went through most of a sixer of San Pellegrino Aranciata Rosso, an Italian soda with a fair proportion of fruit juice. Work was hell yesterday, so the cans were still sitting on my kitchen counter waiting to be washed and recycled.

Today I went to do that, and I detected a marvelous aroma coming from somewhere. Intrigued, I sniffed the cans, and lo - one of them is emitting a very pleasant, warm, bready and estery smell which I identify as yeasty in origin.

I want to brew with that. I've got a couple pounds of DME and an erlenmeyer flask. If anyone has ideas on how to culture from a soda can, please share!

I was thinking I'd boil some wort, pour some into the can, shake it out, and then pour it back into the flask. Is this sensible?

 

[Trail]

Getting antsy, guess I'm gonna do what I said in my original post. Starter wort is chilling in the freezer, we'll see what a little turkey baster action can do. Allons-y!

 

[Warthaug]

Your plan is sensible, and has a reasonable chance of success. Just be aware that you will not have a pure culture, and there will likely be a few bacteria in there as well. I would recommend using a separate fermenter & siphon to reduce the risk of contaminating your future batches of beer.

In my signature there is a link to my blog - I have a whole section on fermenting with wild yeasts, which is exactly what you are planning on doing. I'd also recommend the mad fermentation blog for tonnes of great advice.

Bryan

 

[samorg42]

I sure wouldn't just take a wild yeast and put it into a batch. A small experimental batch might be in order, using your "wild thing" to make a starter. You might well have other things contaminating that soda can, including bacteria from the mouth of whomever drank the soda. You can get detailed starter instructions from Palmer's book. If you have a decent microscope, you can see the yeast and anything else growing in there.

The only batch that I have made that was ruined got a wild yeast mixed with my Wyeast culture and the entire carboy tasted like acrid plastic. (phenolic)

 

[Cyclman]

Never tried it, but you can acid wash yeast, it might kill off bacteria. http://www.whitelabs.com/content/acid-washing-yeast-0

 

[Trail]

Starter's been sitting for eight hours. Some bubbles have formed but there's no krausen to speak of. Need to stop staring at this stupid flask.

 

[Trail]

So there's some stuff going on in there now:

The brown stuff is definitely weird mold, but the white dots look like they might be yeast. What do y'all think? Should I inoculate a new starter with the contents of one of the white dots?

 

[eastoak]

anything is possible but i would be very surprised if a soda had yeast in it from the bottling plant, why would soda have yeast in it?. it seems more likely you have some wild yeast there.

 

[Trail]

I know it's wild yeast, man. I left the cans out, unwashed, and it started smelling yeasty the next evening.

 

[ericbw]

So there's some stuff going on in there now:

The brown stuff is definitely weird mold, but the white dots look like they might be yeast. What do y'all think? Should I inoculate a new starter with the contents of one of the white dots?

I think you should do that! You'll eliminate some of the bacteria, etc. and maybe isolate yeast. This is similar to people streaking wild stuff on a plate/petri dish to identify yeast vs. bacteria or mold. Pick out some of the yeast, and make a small starter that you step up.

Also, someone mentioned that it could be mouth bacteria. It could also be mouth/lip/face yeast (not bacteria). As long as you can live with the possibility of that, it's fine.

It might just all be bacteria and mold and it could be very gross. Tell your guests after they drink it.

 

[tgmartin000]

If you haven't, read the BYO article on harvesting your own yeast. One big thing was to let anything ferment for at least a month, to kill off any bacteria. I think it mentioned botulism. That stuff can kill a man. Just be aware of what you're' doing.

 

[eastoak]

while i do love brewing with wild bugs and do so very often i would not consider bugs from from a soda can since they stand a good chance of being mouth bugs than air borne yeast.

 

[eastoak]

this morning i went out to the garage and saw these two containers of wort from brewing 4 days ago. one container i shook the empty packet of yeast into, and the other i had sipped on to check the bittering levels. guess which is which.

 

[Biobrewer]

So there's some stuff going on in there now:

The brown stuff is definitely weird mold, but the white dots look like they might be yeast. What do y'all think? Should I inoculate a new starter with the contents of one of the white dots?

Everything white on that surface looks like mold, not sure about the brown stuff, maybe just something from the starter itself. There is a good chance you have a ton of mold, a good amount of bacteria, and some yeast. The only way to know exactly what is in it is to culture for single colony selection, replate the single colonies, and either run some phenotyping, genetic typing or use selective media to replate.

If you inoculate with the "white dots" you will likely get a ton of mold. Also, to really select something out of a culture, you need a solid agar-based media, as liquid is free flowing and there is likely a diversity of organisms in there, most of which you do not want.

 

[Biobrewer]

I know it's wild yeast, man. I left the cans out, unwashed, and it started smelling yeasty the next evening.

You may have some "wild" yeast in there, but it may not be suitable for brewing. If you were drinking out of the containers, there is probably a bunch of Candida albicans from your saliva, along with a bunch of mouth bacteria. Ever plated a swab from your mouth? I did this in intro microbiology about 12 years ago, and it was a lot of mold and bacteria.

Like I said, if you want to try to get something out of this, your best bet would likely be streaking for isolation.

Good luck!