How long can liquid yeast be unrefrigerated?

[switters]

I recently ordered a partial mash kit. It arrived while I was out of town. It contains a pack of liquid yeast, which had a small cold pack attached to it. By the time I got home the yeast had been out of the refrigerator for probably 5 days (including shipping time).

How long can liquid yeast be unrefrigerated before it starts to lose potency?

 

[C4PNJ4ZZ]

5 days should be fine. Just make sure to make a starter before you use it. I get my yeast shipped from Austin Homebrew Supply in the middle of the summer (4-5 days shipping) and have never had a problem with the ice packs.

 

[switters]

Thanks for getting back to me. Is the process for making a starter with liquid yeast the same as that for dry yeast, i.e. rehydrate with 100 - 110 F water and let stand for a half hour?

 

[Blender]

Thanks for getting back to me. Is the process for making a starter with liquid yeast the same as that for dry yeast, i.e. rehydrate with 100 - 110 F water and let stand for a half hour?

Nope, you need to make a small batch or wort and add the yeast. (1000 ml ought to do it.) It will grow over the next day or two. Keep the OG at roughly 1.040

Here is a nice little podcast on the subject >> http://www.thebrewingnetwork.com/shows/Brew-Strong/Brew-Strong-12-22-08-Yeast-Starters

 

[Yooper]

Thanks for getting back to me. Is the process for making a starter with liquid yeast the same as that for dry yeast, i.e. rehydrate with 100 - 110 F water and let stand for a half hour?

No, that's not a starter. That's rehydrating dry yeast.

A starter is a mini batch of beer, but no need to use hops. I like to use 1/2 cup DME and 2 cups of water and boil that in a sauce pan for 5 minutes. Then, cool and add to a sanitized growler (or other glass jug). Add the liquid yeast, and cover the opening with sanitized foil. Shake it up and let it go. In a couple of days, use it in your beer. Room temperature is fine.

A starter will do a couple of things- first it'll increase your yeast cell counts, since the yeast reproduce. It'll ensure viability of the yeast, and it will also reduce lag time in the fermenter.

If you want to see optimum yeast pitching levels, there is a nifty pitching calculator at mrmalty.com. I think most people are surprised at how little yeast really is in the White Labs tube or the Wyeast smack-pack. A starter is a good idea with just about any beer you make with liquid yeast.