Liquid Wyeast activated before opening

I have a package of liquid Wyeast about 5 months old. It has been kept in the fridge the whole time. I just pulled it out to use it and the package seems to have been activated. It is unopened, should this still be good to use? The package says good from 6 months of date on package, which I am within.

Thanks.
Phil

 

It will be good to use, but you will definitely need a starter or a stepped starter. There is a calculator at
http://www.brewersfriend.com/stats/
for basic starters and stepped starters. Yeastcalc.com is still down.

 

In entering the limited info you provided into Mr. Malty's yeast calculator online, it shows a viability of only 10% with a date of 7-31-13. And that is most likely assuming perfect storage conditions. With this data it says if you were to brew a beer with an OG of 1.048 you would need 17.7 packs of that yeast to ferment it out without a starter. I think you could either do a multi step starter using the calculator to put you in a general neighborhood of the number of viable cells as you go, or just get some new yeast (what I would do). Depending on the beer you plan on brewing, over 1.050 "ish", it may still be recommended to use a starter even with the new yeast. I don't personally like the idea of putting the effort into a brew and then pitching with weak a weak batch of yeast. Good luck!

 

Flars beat me to it, lol.

 

Thanks guys. Just so I understand that chat, I only need 10% of the yeast package to activate, or it will only be 10% effective? The yeast in question is Wyeast 1056 american ale brew date Sept 18th 2013. Unfortunately my LHBS is closed today and the next closest is an hour away. I will be headed that way this afternoon, but want to brew this morning (only chance for about a month to do it).

Should I try it, or can I make the wort put it in the carboy with airlock, then pitch it tonight?

I am trying an Odells 90 Schilling extract clone.

 

You don't give us the OG, but I'll bet it would take a starter.
You would not be able to pitch for a day to day and a half.

Limited brew time. Pick up two packs of 1056 this afternoon. Smack the packs so they have swelled by the time you get home.

 

Sorry. Estimated OG is 1.054. 5 gallon batch. Pitching tonight with new it is. Thanks.

 

It's 10% viable cells remaining in the pack of the yeast. Where as when new you have around 100 billion viable cells at 96% (appx.) yours is at 10% estimated giving you only around 10 billion. which isn't high enough. You could definitely go ahead and brew, then pitch tonight. I would be very cognicent of sanitation post boil, but it wouldn't be a problem. Also, dry yeast US-05 is the same strain as Wyeast's 1956 and White Labs WLP001 so if you buy yeast you may not use for awhile dry yeast comes in really handy as it stores longer.

 

That makes sense. I do have a unopened dry package of Safale s-04 dry ale yeast. But that is different correct?

 

yep, different strain.