Yeast bank question

[UncleDave]

Hello,

Long time lurker with a question. I've been brewing for about six months, so I'm still new at this game, but I'm curious as to why brewers wash old yeast. Wouldn't it be better to take fresh yeast from an already sterile White Labs vial, make a huge starter, and then split them into their own vials for long-term storage? Seems like this would give you less chance of an infection and overall, healthier yeasties. Am I missing something here?

 

[albannach]

Yes that would be a more sanitary practice. Some people open a fresh yeast vial and, using an inoculation loop, streak a petri dish of growing medium and use that as the master culture. Then they use the rest of the yeast vial/pack to make the beer as per normal.

I personally just wash my yeast because I don't want to buy that lab equipment, I'm too lazy to make a bunch of agar, and I enjoy brewing more than micro-biology

 

[zac]

Dave, Option B is basiaclly what I do.
1. Open vial
2. Split into 12 pieces, and pitch into 12 different pints of starter wort.
3 let that ferment & fall out.
4. take each pint, decant, shake the hell out of it, and split that into 12 quarts.
5. Now you have 144 quarts of starter wort for the price of 1 vial.

This drops yest price for each batch down to below a nickel per.

Albannach, my lab equipment consists of pint jars, quart jars, and starsan!

If anybody goes super-duper cheap, you can just pitch fresh wort onto a cake, effectively tripling the power of a vial. 432 batches from 1 vial.

 

[Aspera]

Washing yeast consumes less wort than the more scientific, sanitary practice of parallel yeast culturing.

 

[UncleDave]

Washing yeast consumes less wort than the more scientific, sanitary practice of parallel yeast culturing.

I like the idea of conserving and this makes sense. On the other hand, you can grow a very nice sized batch from $4 worth of DME. I only brew once or twice a month, so having a small supply of Chico and Irish Ale yeasts should meet my needs quite nicely. I suppose if I brewed more often, washing yeast might make more sense for me. Thanks for the replies, gents.

 

[homebrewer_99]

I brew almost every weekend.

I currently have 70 vials of (mostly washed) yeast on-hand.

If you're lucky you should only need to buy a couple of vials once a year...or every other year.