Yeast Management?

I've been looking for a while and can't get the answers I'm looking for.

I'm trying to figure out how to save and reuse yeast as needed.

We brew 20 gallon batches, conical fermentor

Using MrMalty with a 1.054 OG, stir plate we need 4.65 liters of starter. We'll use 3 smack packs to create this and pitch.

After 7 days, trub was removed, fermentation is finished and yeast was removed. We had approximately 1 liter of material including some trub and a good amount of yeast with some liquid.

We repitched this into a second batch of the same beer.

1 - Can anyone tell me about how much actual yeast we had?

2 - If I wanted to save this yeast for a period of time, can I divide this into vials to create starters?

3 - How much yeast should be in a vial to create a starter? It doesn't look like there is much yeast in a White Labs vial.

Please provide any relevant information.

thanks,

eric

Eric
Get a copy of
Yeast: The Practical Guide to Beer Fermentation (Brewing Elements Series) by Jamil Zainasheff and Chris White

This will explain a lot about the yeast and how to handle it.

I only brew about once a month and I change styles often so reusing yeast directly not the best idea for me.  The only way to really know how much viable yeast you have in any sample of yeast is with a microscope and if I remember correct methyl blue (or something like that).  The methyl blue will stain the live yeast and you count the number of live yeast in a give sample volume.  Sounds like fun, but a little more time and more money than I want to spend right now.

YEAST (the book) goes through the process of estimating the amount of viable yeast based on how you got it and how long you've stored it.  You can store the yeast slurry in the refrigerator for a couple of weeks at least.  You will lose some of the cells, but there will be cells left to get your next starter going.

I have recently started storing yeast in sterile water at room temperature.  [I have also successfully (a bit limited success) storing yeast in the freezer.]  In short you use a petri dish to culture and grow individual yeast cells into little mini colonies, then scoop up several little colonies and store them in STERILE (as in autoclaved) water.  Take a small drop of the yeasty water and put it in about 2 ml of STERILE wort.  Let this grow a day or so, then transfer to 10ml STERILE wort to grow a little more.  The next step up is 100 ml then to a full starter size.

This the first time I have tried this and I'm at the full starter size.  It appears to be working well.

I'll dig up the web addresses of my source information and post it later.

Good Luck, David

Here are three of the most pertinent online references that I have used.

http://www.alsand.com/beer/yeast/index_E.html

http://brewery.org/library/SterileDW1096.html

http://www.maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices