Racking onto yeast cake

I recently visited my LHBS and the guy there told me that many times he brews a new batch on the same day he racks his last batch from primary to secondary and then racks the fresh wort into his primary onto the yeast cake left over from the previous batch. I'd like to start doing this so I can save the $6 I pay for yeast each time I brew. Anyone have any experience with this? Anything I should know before I try it?

Yes....it works very well!

After racking off the yeast, just cover your bucket or carboy with aluminum foil or plastic wrap to keep it clean.

Works great. Consider the strain you are using and brew a batch that calls for that strain as well. One rule has been go darker with the second batch but if you rack most of the wort/beer off I don't think thats a big problem. If you do the rack onto the old slurry do a blow-off tube. It'll more than likely ferment over. My 1st time I did this when I was using a plastic bucket it went so fast it blew the cover off. Haven't done it in glass yet because of my normal practice below.

Consider also saving the yeast in sanitized bottles. Leave them half full and "burp" them to release some of the pressure initially. Flip tops work great for these but always do a starter with them to make sure they're good. Extremely anal sanitation if you do this. I typically get 4-8 batches off of one $6 spend. You could get more by going three generations deep but I'm happy if I get 4 batches out of 1. Search for Yeast + Slurry for some great threads on racking onto and saving slurry.

I do it all the time! If I'll be brewing in a week's time or less, I just leave it in the primary carboy with an airlock on top until I'm ready to fill it with the new brew. Have a blow-off tube and bucket ready - this method will really kick-start your fermentation and you may have a huge amount of krausen (frothy yeast head).

Take a look at this thread.

I never bothered with this before, because I always just used cheap dry yeast. The cost of yeast for a batch was a whopping $1.50 (and that's just because I use two packets, which might not be necessary.)

But, I'm starting to experiment with different yeast strains now and the smack-packs are something like $5.00 at the LHBS, so I'm going to shoot for re-using the yeast at least 2 or 3 times before dumping it down the drain.

-walker