Yeast culturing

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

SGT-RIEL

Active Member
Joined
Feb 1, 2009
Messages
37
Reaction score
0
I've read the post on yeast washing, but what I'm looking for is a tutorial on splitting up a live culture into pitchable amounts for long term use. Any help or advice would be grateful. Looking to stay busy in between brews.
 
What I'm getting at, is buying a pitchable vial of yeast and culturing it further into more pitchable vials for use 6 months to a year from now.
 
I think you would look for a wiki on building a really large starter and then just split that up.
 
What I'm getting at, is buying a pitchable vial of yeast and culturing it further into more pitchable vials for use 6 months to a year from now.

That is not commonly done so I don't think there will be much literature on it.

Normally pure cultures are saved for reuse by culturing them on media, storing them cooled (or frozen), then stepping the back up to pitchable size.

If you wanted to go for it, here are my first thoughts on a possible procedure:

1. Sterilize (in oven, autoclave, or pressure canner) everything but the yeast: flask, foil, funnels, whatever. I'd have the starter+nutrient in the flask already and sterilze in situ. Allow to cool.*

2. Pitch yeast into flask of starter, preferably on a stirplate.

3. Allow it to run long enough that you are convinced there are no fermentables left.

4. Sterilize some bottles and funnel, sanitize caps. Based on my unscientific testing the White Labs vials also survive pressure sterilization and will still seal, although some of the flanges warp. I think we are going to want more volume than a vial, though, unless you can achieve massive starter density in step 3.

5. pour the maxxed out starter into the bottles, cap**

6. store in fridge (preferably inside a bin in case there are contaminants or residual sugars and they BTFU) until use.***

7. I'd still pitch these into starters instead of into the primary, but then again I generally do not consider vials/packs directly pitchable anyhow.

Frater Mus
* I love pressure canners for this. I recently bought a taller canner that allows me to sterilize even my biggest flasks standing up with the foil caps in place.
** yes, I know that capping will be controversial. But I think that if the OP is storing a half-dozen bottles of "pitchable" starter in the fridge caps are more practical.
*** Mr. Safety would suggest wearing eye and hand protection in case of overpressured
 
AFAIK no one sells freezing kits. I bought most of my lab gear off eBay and basicsciencesupplies.com.

Keep in mind that frozen yeast cultures are not pitchable in any normal sense of the word.
 
would it hurt anything if i used the plastic corning vials my yeast comes in for my frozen yeast bank?
 
would it hurt anything if i used the plastic corning vials my yeast comes in for my frozen yeast bank?

Provided that you've autoclaved/pressure-cooked the vials first, no. The biggest challenge to freezing yeast samples is the frost-free freezer. You need to pack the vials in a small cooler with ice packs to insulate against the defrost cycling of your home freezer compartment.
 
Back
Top