I had planned to brew a batch of Oatmeal Stout two weeks ago. I crushed my grain and I made my starter (WLP005). I started a new job the first week, then the second week we had an early winter storm that knocked out power for a few days. The recovery effort and getting back on track with my new job has delayed brewing a little bit. So now I am thinking about Reviving a Yeast Starter!
On the one hand I put the 2L starter in the fridge when it was done. I let it go 3 days on the stir plate with the intention of chilling to settle the yeast, then pitch the slurry on brew day. But now its been 14+ days. I could probably still just pitch it and call it fairly fresh. However, I am really looking to nail my fermentation for this batch of O.Stout.
I think I might decant the spent wort, then resuspend the yeast in a one gallon growler with some fresh 1.040 starter wort. I’ll let it ferment out, crash chill, decant and pitch. That will increase the cell count a bit, but I am thinking it will put some fresh life back into the yeast.
Any thoughts or experience from our dedicated readers?
BREW ON!
Nathan
Go right ahead — I’ve read this recommended (or at least condoned) from a few sources as a way of “doubling up” the starter. The actual doubling up is probably un-necessary, but it certainly won’d hurt the yeast.
Eric
Don’t you just love New England weather, and today it’s near 70!
I essentially the same thing when washing and reusing my yeast from the primary. I haven’t had any issues so far and it brings down the cost per batch. I make two 2L starters from the slurry pulled from the primary, crash chill, decant, and separate between 4 – 1pint mason jars and store in the frig. When it’s time to brew, I will make another 2L starter and pitch. I’ve made 4 generations of the same yeast strain and all have been active in the starter.
This was my inspiration for yeast washing:
http://www.beersmith.com/blog/2008/07/25/yeast-washing-reusing-your-yeast/
I was curios to see if I would be able to distinguish taste between the washed yeast and yeast from a vial. After all, breweries re-use the yeast cakes many times over. So I made two identical batches, one with a 4th gen strain and one with 1st gen, my brew buddies and myself were unable to tell the difference.
As long as you see activity in the starter, I would say you are good to go.
chris
If the yeast has been at fridge temp for 14 days it should be fine. Pour off the wort, wash with room temperature sterile water, allow to settle, pour off water, repeat and pitch. The only times i dont do this is if i have made a dark beer and i’m looking to make a light beer or if i have made a very hoppy beer and i’m going to make a more subtle beer. Refermenting the starter seems like a lot of effort when you already have a large amount of viable yeast there.
Mike
Here’s two questions from the great comments above. Would you do the “revival” on a stir plate, or just in a large growler, then crash cool and pitch the slurry? And is washing the yeast really necessary if I was to just decide to pitch the slurry.
Discuss…
Aaron
I would just decant from the fridge and pitch another 1000ml of starter wort to get the yeast active. I don’t think 2 weeks is going to effect viability more than 10%. but i would let it finish out for 3 days, crash and decant. the reasoning behind the 1000ml is that you probably already have the growth you need from the 2L starter and you just want to get those yeasties ready for work. if you do another 2000ml you may more growth and end up overpitching. at any rate… i haven’t see anyone post http://www.mrmalty.com ….
chris
Its not necessary to wash the yeast but it gets rid of any alcohol and gunk from any lysed yeast. It isn’t really necessary to revive the yeast, they’ll perk up once they hit fresh wort.