Harvesting yeast

[Brownbeard]

I am going to collect the yeast from my scottish ale this weekend when I put it in secondary. I want to use it in a couple weeks to do an oatmeal stout. I wonder what size jar I need to use for the yeast I collect. I ask because we are now getting a whole lot of empty baby food jars and was wondering if this might be a good way to keep some yeast. If I were to store the yeast in the jars for a couple weeks, after sanitizing, will it be OK? My plan is to collect the trub from the bottom of the primary, put it in the baby food jars and seal and store in the fridge. Then when I am ready to use it, make a starter using the stuff in the jar.

[chris1kanobi]

That would work, however the yeast will go dormant in the fridge, and yeast mutation and autolisis (yeast eating eachother) off-flavors will increase with time. I wouldn't keep yeast for more than a year, or re-use the same strain more than 5 times. I normally collect the trub from my primary into a flask or apple juice jar (something with an airlock). Then I pitch the entire slurry into a fresh batch, no starter. The slurry can be kept for several weeks at room temperature. A thin layer of beer will rise to the surface and protect the yeast below. This could be done with secondary trub as well, agitate or add o2 and you will have action in a matter of hours. Welcome to yeast farming.

[BeerBelly]

I have been collecting in the White Labs vials. It is already labeled with the yeast type.

[S.F.B.]

I harvest the way you are describing when I have 3-4 batches to do back to back. I use a pint Ball-Mason jar with ring and lid. Sanitized, of course.I usually scoop out enough of the trub to fiil to 10 oz. or so. The only thing I would recopmmend is don't use it after 14 days. 7-10 days is as far as I have been told to go.

[OldHooky]

I just use beer bottles with a #2 stopper with an airlock.

[bierboy]

Originally posted by S.F.B.
I harvest the way you are describing when I have 3-4 batches to do back to back. I use a pint Ball-Mason jar with ring and lid. Sanitized, of course.I usually scoop out enough of the trub to fiil to 10 oz. or so. The only thing I would recopmmend is don't use it after 14 days. 7-10 days is as far as I have been told to go.

Have you heard a reason for this? I have always seen that you can keep yeast like this a long time as long as it is under beer or deareated water.

[S.F.B.]

Originally posted by bierboy
Have you heard a reason for this? I have always seen that you can keep yeast like this a long time as long as it is under beer or deareated water.

I haven't ever asked. I have been told and like one of the sheep have always went by it. I will ask next time I am at my local shop.

[Brownbeard]

So I harvested the yeast, and have 4 babyfood jars in the fridge. They have about a half inch of beer sitting on top of a nice thick yeast cake. I am going to use this for my next batch of beer, with a starter. Hope it works out.