WLP001 washed yeast question

[jjbanks]

I washed this yeast from an ipa about 3 months ago. I am looking to repitch this weekend into a new batch. Does this look like a good amount to pitch and if so do I need to do anything such as a starter before I do so? Thanks for any responses.

View attachment ImageUploadedByHome Brew1420761742.602889.jpg

 

[Mike_kever_kombi]

It's ok amount wise.

With it being 3 months old I would decant and make a starter.

 

[olotti]

I'm glad u asked this I have the same question but my amount is a little less than that so I was going to combine two jars. But that looks like enough and yes you'll want to make a starter to make sure it is viable and not infected which from my gathering you'll b able to tell if the starter doesn't take off or has a funky smell.

 

[WoodlandBrew]

You can estimate 1-2 billion per ml if it was unwashed from an all grain batch, or 3-4 billion per ml if it was extract. 3 months doesn't impact the viability much, but can reduce vitality.

Instead of a starter my preference would pitch that yeast into 10% of the wort and then add the remainer after a couple of days once fermentation is going.

 

[olotti]

3 months doesn't impact the viability much, but can reduce vitality.

Yeah that's what I meant. Wake me up a little after their slumber.

 

[jjbanks]

You can estimate 1-2 billion per ml if it was unwashed from an all grain batch, or 3-4 billion per ml if it was extract. 3 months doesn't impact the viability much, but can reduce vitality.



Instead of a starter my preference would pitch that yeast into 10% of the wort and then add the remainer after a couple of days once fermentation is going.

That seems like almost the same thing as a starter except higher SG and the risk of ruining 10% of my wort. Won't a simple 1 liter starter be able to test the viability of the washed yeast sample?

 

[Remmy]

Based on that picture, that yeast cake looks next to nothing. If that were mine, I'd make a starter and step-it-up. Based on the level of yeast in there, I would just buy another vial of yeast if I were you.