How long is too long

[cruizer8]

I had some extra runnings during my brew day so I decided I would give wild yeast a chance. I just got done wrapping a hop sock over a gallon container that was half full and set it outside. I plan on using this as a starter if anything catches.

My question is: if it does start, how long can I keep it before I need to pitch it in a beer? I won't be able to brew for another 2 weeks, will it last that long or is there anything I can do to make it last that long?

 

[wozzer]

I think the question will come down to: how do you know what you are seeing is yeast?

I've set aside some wort after a mash and gone to bed before the boil because it was too late in the night to stay up any longer. When I got up, the unboiled wort was well alive - with something.

When I tasted it, it was highly acidic. I set it on the boil and brewed it as per normal, but it wasn't your average brew. It was a sour-mash.

I guess you could stack things in your favor by ensuring a dominance of wild yeast from the get-go - but how? That's the question to address. I wouldn't know how.

 

[ChugachBrewing]

I would give it 24-36 hours to "catch" anything, then put a lid on it and let it ferment. See what you get after 2 weeks. It should be fermented out by then. Taste it. Delicious? Pitch. Nasty? Don't.

 

[sweetcell]

I just got done wrapping a hop sock over a gallon container that was half full and set it outside.

are you using a standard gallon jug, with a narrow opening? that might not work. you want yeast to fall into the wort. a small opening like that limits your chances. when folks go yeast hunting they typically use pans, wide tupperware, etc - something with a lot of exposed surface area.

a jug might work, but you'll have much better chances with a bigger opening for the yeast to fall in.

 

[ChugachBrewing]

i envisioned this: http://www.amazon.com/dp/B0000DDVN7/?tag=skimlinks_replacement-20
I recommend something similar if you are using a simple gallon jug

 

[cruizer8]

The jug I am using has a 3" opening. Would that be big enough? And how do you know if it has caught anything yet?

 

[andrewsbromley]

From what I've read before, people usually leave containers for catching wild yeast out just overnight or maybe for 24 hours. If you caught any yeast, you should be able to see signs of fermentation after a week at least I would think. You can always just sample the starter after a few weeks and see if it has any characteristics you like.

I think the trouble is just that you don't know what you're working with. Even if you get hold of some wild yeast, you most certainly have a host of other bacteria and mold. When you subsequently repitch the starter, the proportions of the different organisms will change, but you won't really know how. If you want to be scientific about it, you should plate the starter after you start to see some activity/growth. Based on the appearance of the different colonies, you should be able to isolate the yeasts. Propagate and pitch one or a few different yeast colonies in separate batches, and repeat the process until you have something you like. You may not have the equipment to undertake his approach, but it seems like the only way to get any kind of consistent results and avoid some of the troubles of a more laissez-faire method.