Dumping a 2nd wort on yeast cake

Thinking of doing something I had not done previously but see a lot of you guys doing: racking a completely fermented beer from the carboy and immediately pouring a new, cooled wort on the yeast cake to ferment a 2nd beer with the same yeast.

(1) What do I need to know here to make sure it all goes smooth?

(2) What about the trub and the blowoff junk ringing the top of the carboy from the 1st beer that is not getting cleaned out/off - will this affect the 2nd beer's flavor?

(3) How many successive beers can I make like this before it is time to dump the yeast and clean the carboy?

Thanks!

 

In short reply: don't

Longer: you will most certainly exceed the recomended pitching rate for whatever style you are brewing, may pick up autolosys(sp?) flavors from the dead yeast, and additional off flavors from the remaining trub.

Take a listen to yeast washing: http://thebrewingnetwork.com/shows/543 and repitching yeast: http://thebrewingnetwork.com/shows/492 for guidance on what to do. Following these procedure, you can easily go for 5-6 generations of repitching.

Regards,
Jason

 

Oh, and forgot to mention there is an excellent thread on washing yeast stickied in this forum: http://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

 

Gotcha. Those were exactly my concerns.