Yeast for possible reuse

[redrocker652002]

OK, so I put some of my WLP001 in mason jars and stuck them in my fridge in my shop. I was going thru the crap out there and realized it was still in there I labeled it to be Feb 17th of this year. Is this stuff still good? One is a small jar about half full with light grey matter and, I am guessing, leftover beer on top. If it isn't any good, I might as well toss it and clean the jars, but if it is, I might use it for a Blonde Ale that I plan on doing in the next month or so.

I should add it was originally used in a single hop Pale ale with a small amount of dry hops.

 

[day_trippr]

The Homebrew Dad yeast calculator says yeast from Feb 17th is now 55% viable, while the Brewer's Friend yeast calculator says it's 46% viable.
Otoh, the Beersmith3 yeast tool says it's only 5% viable (I never use that tool).
I'd go with 50% - and definitely make a starter before pitching it...

Cheers!

 

[Bassman2003]

Try the Yeast book method of verifying. Pour the old wort off, add some fresh wort on top, shake it, let it settle for 10-20 minutes and see what comes to life. Your viable or alive cells will go up into the wort and start eating. So basically, pour this wort into a new starter as these cells are the only ones you will be able to use. Leave behind the dead cells.

 

[Zenmeister]

Edited because I totally screwed up this post. Corrected one below.

 

[Zenmeister]

Leave behind the dead cells.

How do you leave the dead cells behind?

 

[Bassman2003]

Just siphon or pour off the new good wort with the live cells into your awaiting starter. Leave the dead cells at the bottom of the container.

 

[hottpeper13]

I leave a small amount of beer in the FV, then swirl it all up and pour into a 2 L beaker. Let it set for 10-15 min. then pour off the cloudy liquid into an Erlenmeyer flask leaving the sediment behind. No washing, no rinsing just settling.

 

[CascadesBrewer]

OK, so I put some of my WLP001 in mason jars and stuck them in my fridge in my shop. I was going thru the crap out there and realized it was still in there I labeled it to be Feb 17th of this year. Is this stuff still good? One is a small jar about half full with light grey matter and, I am guessing, leftover beer on top. If it isn't any good, I might as well toss it and clean the jars, but if it is, I might use it for a Blonde Ale that I plan on doing in the next month or so.

I should add it was originally used in a single hop Pale ale with a small amount of dry hops.

I have had pretty good luck reusing yeast, but once it is past about 4 months, it can be a bit of a gamble. At that point I generally will make a small starter (say 0.5L to 1L) and add a few spoonfuls of the slurry. If it kicks off in a day or two, then you know you have some healthy yeast. You can then store that yeast back in a jar for future use...or sometimes that gives me the motivation to brew a beer to use that yeast.

 

[redrocker652002]

Thanks for all the replies. I guess I need to work out a schedule where I can brew one less hoppy beer and then once it is done and in the keg get another one going and figure I will need to bottle that one.

 

[CascadesBrewer]

Thanks for all the replies. I guess I need to work out a schedule where I can brew one less hoppy beer and then once it is done and in the keg get another one going and figure I will need to bottle that one.

I tend to reuse yeast harvested after fermentation as I just find it is easier. Fermentation is going to make all that yeast anyway, so why not just scoop out a little to save vs dumping it down the drain? I have reused yeast from dry hopped beers or from 8% ABV beers, though it might not be ideal.

But "overbuilt starters" have some advantages, especially if you are pitching the yeast into a beer that is not ideal for harvesting. Basically, instead of making a 1L starter, make a 1.5L starter, saving 1/3 of the yeast to use for a future batch. When it is time to brew again, just spin up another 1.5L starter. (Adjust as needed for cold fermented lagers, high gravity beers, larger/smaller batch sizes, etc.)