Wild yeast

[Battleaxe]

Last week I made 2lts of wort using light DME I used 1lt for the starter and put the other in an empty bottle I had cleaned out and saved. It has sat on the side in my kitchen unattended for 5 days I assumed that it should be OK ish for a while as I intended to make another starter for next weekend.

Today I noticed the bottle had a lovely looking krausen inside and when I picked it up the plastic bottle was rock hard. I unscrewed the top releasing the pressure and I was greeted with a not unpleasant vinegar fruityness.

Can I harvest the yeast and use it in something?

Or does the vinegar smell mean it's a Gusher type bug that I've contracted?

Also this does show how if you create the right conditions you can pick up an infection without even trying!

[Fil]

you have undoubtudly got at least one yeast strain going on in there

Using the liquor as is may prove fruitful?? but could also prove a failure due to other contaminates in the liquor, Isolating the yeast clutures in the liquor may offer you a much better chance of success..

To isolate a yeast culture you need to 'streak' a 'plate'
http://bootlegbiology.com/diy/isolating-yeast/
which can involve a little reading up and a nominal cash outlay on petri dishes and the loan of a pressure cooker as a diy autoclave to sanitise.
Though i refer you to the Yeast book by chris white for an informed source..
http://www.amazon.co.uk/Yeast-Practical ... 0937381969

[orlando]

you have undoubtudly got at least one yeast strain going on in there

From your description ,my money would be on acetobacter or lactobacillus, the latter one of the most ubiquitous bugs around and rides on the back of grain, so every time a cloud of it goes into the air it contaminates everything it falls onto. If you fancy making a Lambic or a sour beer it should be fine, possibly a little unpredictable but an interesting experiment, let us know if you do.

[wilfh]

Looks like you've got something interesting. I'd save a gallon from a light brew, maybe even unhopped and leave it for 6 months. Add some beer yeast to make sure that it at least's ferments properly and see what you get. You might be surprised! I've had one great, one ok and another rubbish so far.

In the meantime do think about your sanitary regime otherwise you might end up with more sour beer than you bargained for.

[Battleaxe]

As soon as I realised I had something wild going on I evicted the bottle to the shed... As not to spread a brewing plague through my house luckily my brewfridge and Gear is kept upstairs in the disused Hot water tank cupboard so nothing has had chance to come into direct contact.

ive been reading about wild yeasts and brewing also how to culture strains it's just another thing to "TRY" lol

[Sadfield]

As soon as I realised I had something wild going on I evicted the bottle to the shed... As not to spread a brewing plague through my house luckily my brewfridge and Gear is kept upstairs in the disused Hot water tank cupboard so nothing has had chance to come into direct contact.

ive been reading about wild yeasts and brewing also how to culture strains it's just another thing to "TRY" lol

But you picked up the wild yeast/bacteria by leaving wort in your house, the little beasties are already living amongst you....Mwhaaaahaahahaaa... It's their house now!

[Battleaxe]

It was in a sealed un sanitised 2lt lemonade bottle that I rinsed out... Tbh I think if you left any warm sugary liquid on the side something would take up residence before long.

I haven't had an infected batch yet and were on AG#13 and many kits before that. (Touch Wood)

[orlando]

..Mwhaaaahaahahaaa... It's their house now!

It's always been their house.

[McMullan]

A sterile agar plate left open for 10min or so in a fridge, or any other brewing area, is very educational, after incubation at fermentation temperatures for a week or two Not much we can do to eliminate the problem completely. It's a natural component of air. Pitching healthy yeast and promoting a shorter lag phase is part of the solution. Yeast take care of things more effectively than we do. They have access to 'chemical weapons', apparently.