Using harvested yeast

Brewed a batch of a summer ale about a month ago. Turned out fabulous. Fermented in primary for a week, then need the primary for another batch (honeyweizen), so racked to secondary and harvested the yeast by scooping it into a small mason jar, and kept it in the fridge since. The summer ale turned out great, so I am hoping to brew a batch or 2 this weekend.

What would be the most advisable way to reuse the harvested yeast for both batches?

If it’s been about a month, I’ll usually take it out of the fridge, open it, spray the outside liberally with star-san, pour off the liquid on top, and just dump it in the fermenter. If it has been longer than that, same procedure, but about a week before brew day dump it in a starter wort. Yeast are really forgiving, provided your sanitation procedures are good. :cheers:

+1 to Pork Chop. When ever in doubt make a small starter for the yeast cake.

So pretty much pitch it the same way you would fresh yeast? Perhaps make up a starter, but either way, brew up the wort, and then add the yeast/starter as I would fresh yeast.

Use about 200 - 300 ml slurry for an average beer. I add it to some saved wort and try to pitch at high krausen. But you don’t need to, I just like to give the yeast a head start. I don’t know if it’s good practice but it’s what I do anyway.

Thanks. That helps me out, knowing how much to pitch.

Here is some links to more information on harvesting and repitching.

http://www.homebrewtalk.com/showthread.php?t=519995

I am estimating 2 billion cells per ml in my harvested yeast. I filter to keep boil hops and some break material from entering the fermentor, so the harvested yeast is very clean.
Over a month old i will make astarter with some of the harvested yeast. Here is some information on cell growth in a starter based on the amount of fermentables rather than volume of yeast.

http://braukaiser.com/blog/blog/2013/05 ... st-growth/

Pretty much… If you have any concerns about the viability, a small starter is never a bad idea, but I try not to stress out about these kinds of things. I like to err on the side of overpitching with harvested yeast.