Rescuing some "expired" yeast

[bannerj]

Was going to use some white labs 545 for a strong dark belgian. It was discounted at the brew store because it was past it's prime date by a month. I've never done a yeast starter before and was excited to get that learning curve going.

Problems:
*I didn't have 2-3 days to let krausen form and a cold crash before my brew date. I was going to pitch it at high krausen, BUT
*in my haste, I didn't let the yeast warm to room temp.

So, I ended up using 2 packs of safale T-58 in a pinch.


NOW I have had 3 days of the 545 starter looking good. HOWEVER, I went with Palmer's DIY starter method for airlock on the starter: a sanitized Jim Beam bottle with a large piece of plastic wrap covering the majority of the bottle and a rubber band loosely holding the plastic in place.

So I'm afraid of infection.

I'd like to cold crash the starter, pour off the 'beer' and split the yeast between two old white lab vials I've got.

Thoughts? Tips? Wisdom?

 

[Chamuco]

I wouldn't worry about an infection since you kept it covered. If you are using it soon, just cap the JB bottle and store it in the fridge. If you are planning on storing it longer, I'd decant into a mason jar, top it off, put on the lid and store in the fridge until you are ready to use. The less you mess with it the better.

In hindsight, you could have skipped the cold crash on that starter and just pitched it after it took off. Nothing wrong with taking the Saf(e) route. Now you need to brew the same beer and use this starter to compare the two different yeasts.

 

[DonnieZ]

As long as your starter has active fermentation going on, there will be positive pressure in your starter bottle.

A yeast starter is nothing but a very small scale batch of beer. Yeast east the sugars, and then create alcohol and CO2. That CO2 goes somewhere, and out the neck of the bottle is the only place. If CO2 is going out, microbes have a very difficult time getting back in.

Once it's done fermenting though I'd put sanitized foil, a sanitized lid, or sanitized plastic on it. If you can't brew right away, put it in the fridge until your next brew day. I'd take it out as much as the day before you're going to brew and let it get to ambient temperature. You can even step it up again by decanting the beer that's sitting on the yeast at the bottom of the bottle and putting more wort in the bottle.

 

[bannerj]

I've got to do some reading about cell population in yeast growth to get an idea of how much I'll have now after the starter. I'm wondering if I can decant this and split the yeast into two separate sanitized vials. Then when I brew next in a month or so, maybe I can then do a stater properly again a couple days before brew day.

I'm glad that you both think that the yeast will be safe from infection. The CO2 moving out/upward and not allowing anything nasty back in--this is what I was hoping.