« on: September 19, 2013, 01:28:37 PM »
My standard approach is to do the simplest process first and if it doesn't work for me then I add complexity as needed. There was a thread a little while ago about how pitching on a yeast cake is a bad idea, but in my experience I've really liked the results - at least in certain circumstances.
I usually schedule back to back brew sessions about a week or two apart with a smaller beer (ie a Scottish 60/- with Wyeast 1728) brewed first and then a big beer (like a big English Barleywine) brewed second. During the barleywine boil, I rack the Scottish into a keg and leave the yeast in the fermenter. Once the barleywine is chilled, I put it right on top of the yeast from the Scottish and let it rip. My philosophy is that the carboy was sanitized when I put the first beer in there, so I don't even bother cleaning it out. If you read the other thread about pitching on a yeast cake, you'll see that there are lots of opinions about whether this is a good practice or not, but both my beer that was selected in a Pro Am competition and my 41 point barleywine were brewed using this method so I have no complaints.
In my experience, using this method is best for yeasts that ferment clean - where the yeast doesn't contribute a large part of the flavor profile of the style. German hefs and Belgian dubbels, tripels, etc. get too much of their flavor profile from the yeast and using this method hasn't worked well for me. My hunch is that the large volume of yeast results in a situation where there is very little yeast reproduction and the lack of a lag time results in a lower contribution to the character in the finished beer.