re using lager slurry

[gwt]

I currently have an anchor steam clone using wl 810 San Francisco lager yeast happily bubbling away @ 58 degrees. My plan is to leave it in primary for 4 weeks and then transfer to secondary (keg) for conditioning and lagering. My question is, if I want to re use this lager slurry for my next batch (American standard lager) do I need to add the slurry to some sterile wort in order to wake it up or can I just use the slurry as I have done in the past with your average ale slurrys. So the main gist of the question is; do lager slurrys act the same as ale slurrys? Thanks

[brewinhard]

You can repitch some of this yeast cake into your next cooled batch, no problem, just like ale yeast. In fact, I feel that lagers actually benefit from this as they begin fermentation a bit faster for me without having to build up such a big starter. BTW, I would think that your Cal Common would be done and ready to transfer in 2 weeks, maybe 3 at most with letting it warm a bit at the end to reduce any possible diacetyl/sulfur produced during the fermentation.

[gwt]

thanks for the advice. I plan on leaving it in primary for 4 weeks because I am at capacity right now, 5 kegs ready and 10 gallons in primary. I thought that 4 wks would give me time to clear stock and give it a nice chance to clean itself up. I really need to drink faster and get more kegs!

[Quin]

Four weeks is about the max I would try to store a yeast without restarting. You will get a healthier fermentation if you make a starter as you indicated. I prefer to use 2 vials for making starters for 10 gallon batches.

So if you're using the yeast pitching rate calculator at mrmalty.com, you would
- dial in a beer (any OG and volume) that would need 200 billion cells - 1.048 lager 3.0 gallons
- type in the date your active fermentation ends for production date - at 4 weeks 50% viability
- Note the mL of yeast slurry required on the "Repitching from slurry" tab - 186 mL
- Type in the characteristics of your next wort- 1.048 lager 10 gallons
- Assume your starter will be around 95% viable; you would need a 5L starter on a stir plate.
- Add the 186 mL slurry to a 5L starter on a stir plate for at least 24 hours

Note: This is more than just waking up the yeast. You are growing them up from 200 billion to 674 billion cells.