5 month old slurry.... make a starter with some or pitch it straight?

[luckybeagle]

I've got roughly 20 ounces of unwashed, thick slurry that I harvested from a batch of Belgian Blond Ale that I brewed back in February of this year. The strain is Wyeast 1388. I want to brew another Belgian Blond (Affligem clone) and am trying to decide if I should make a 1.5L starter with about 1/3 cup of slurry, or if I should make assumptions about its viability and pitch it straight. The slurry looks and smells fine and fresh--no mold or dead yeast/wet cat food smell)

If I pitched it straight, I would assume it has maybe 0.5 Billion cells per liter and would add the whole thing to 5 gallons of 1.063 OG wort.

If I made a starter, I'd pitch the 1.5L starter and assume it had 250 billion cells (0.78 cells/ml/plato, standard ale pitch rate).

What would be the best approach to increase the odds that I don't underpitch or grossly overpitch?

 

[madscientist451]

Make a starter and don't worry about over-pitching, or if you want to worry, pitch half of the starter.

 

[Golddiggie]

Make the starter, let it complete, chill/cold crash, decant the spent wort and pitch the slurry. I would start this at least four days before your planned brew day. Five would be a better idea IMO. That way, if the starter (assuming you have a stirplate to use) takes longer to get going, and finish, you still have time to cold crash and decant. That's my normal process for when I use starters.

IME/IMO, if you have any doubt about how much viable yeast you have to pitch, make the starter. Also be sure to infuse the wort with enough O2 for the yeast to be happy/healthy (for stronger cell walls during initial replication stage). You could also add some yeast nutrient to the brew during the last 15 minutes of the boil to help them even more. I've found those small steps can do a LOT for the yeast. Well, the solid oxygenation isn't really a small step. I do that for every batch using pure O2 and get strong fermentation very quickly post yeast pitching.

 

[couchsending]

Starter for sure


You don’t want a bunch of dead yeast sitting in your beer. There’s a ton of dead yeast in that slurry.

 

[odie]

I'd just pitch about 1/4 cup of that slurry...supposedly dead yeast is food for live yeasts too...or so I've heard once...probably just a myth...

All my saved yeast harvests are about 1/2 pint total of pure yeast cake under some beer. But I fine strain the kettle wort first.

If you have 20 oz of slurry I'm guessing it's lots of trub too. Do you filter or strain your kettle into the fermenter or just dump everything in?