Liquid yeast question..

[Phipcice]

Crud, I apologize, i posted same question in general chit chat by accident.. Phone version of forum is a little confusing..

I have a vial of White Labs Belgian liquid ale yeast WLP550, been in refrig since delivered Jun-06-12, "best before date" reads Sep-04-12. Is this date "bible"? I'd like to brew tomorrow but if this yeast shouldn't be used I'm SOL cuz brew store isn't open til Monday. Any input would be greatly appreciated...

 

[kh54s10]

Also answered in your other post:

The actual manufacturing date is 4 months prior to the best by date. If you are making a 5 gallon batch you should have already made a starter. The older the yeast the larger it needs to be.

If it were me I would make a starter and put off brew day until it is ready.

Mrmalty.com and yeastcalc.com are good sources of information on starters and have calculators to determine how much yeast you will need.

 

[Pappers_]

If it were me, I would either make a starter or buy more vials. If you have enough extra extract, if you did a starter this afternoon, it would be ready by tomorrow afternoon.

If you can't make a starter, don't have extract for the starter and can't get more yeast, then I would wait. The issue, I think, is underpitching. FYI, unless you are brewing a low gravity beer, you need to make a starter with liquid yeast, whether or not it is past the 'best by' date or pitch more than one vial of the liquid yeast. Underpitching yeast puts more stress on the yeast, and stressed yeast produce more flavor compounds that can lead to off-flavors.

Dry yeast has significantly more cells in it than liquid yeast and doesn't require a starter.

All of the above being said, if you pitch the vial of liquid yeast you have, you will make beer. The yeast will reproduce, gather their strength and ferment your wort. It may take them a little longer and your beer may not win awards, but it will still be beer.

If you like reading, there is a great book called "Yeast" by Chris White (of White Labs) and Jamil Zanisheff (spelling?) that is outstandng. Jamil also has a website with some info on yeast, pitching rates, and starters at www.mrmalty.com

 

[WoodlandBrew]

The viability is likely down to about 50%. If that was a surly that you saved in your fridge it would be near 10% viability at this point.

Use Mr. Malty, but have it calculate a starter for you with 50 Billion extra cells.

... Although, Belgian strains are known for their ester profile and under pitching a little will bring that out more. Also ferment it toward the top of the temperature range to enhance the flavor as well.

This Saison made with WLP556 (a very similar strain) is one of my wife's favorite beers:
http://woodlandbrew.blogspot.com/search?q=terri

 

[Pratzie]

I'd recommend starter, cold crash, dump the slurry, add more malt extract, ferment again, cold crash again, dump slurry again and see how much slurry u have in ur vial. If not enough (using Mr Malty slurry recommendations), repeat. but at that point ur gonna be spending as much on malt extracts as u would on buying another yeast pack.

 

[WoodlandBrew]

... but at that point ur gonna be spending as much on malt extracts as u would on buying another yeast pack.

That's a good point that always bothers me about crashing and dumping the beer from the starter down the drain. One alternative would be to dump everything into the fermenter so as not to waste the beer, but that would only be a viable option if the wort was very similar.
What I have done in this kind of situation is to use the wort for the beer I am making as the starter wort. I added the yeast of unknown viability to half a gallon of wort in the fermenter and let it go for a day. Then I added the remaining 5 gallons of wort. It's important to keep your wort as sterile as possible if you try this method of next day pitching.