Originally Posted by Donner
When you rack your beer it's almost impossible to remove all the wort from the fermenter, so if you wanted to reuse that yeast cake you have a couple of options. One is to make a darker beer so as the color difference wont impact your beer that much.
I am going to throw the experience/logic card on this one and say not true.
Logic first: You can siphon off 99% (or more)of the beer (it really isn't wort anymore, is it?). I personally leave less than 6 oz in the bottom (which would be 1% of a 5 gallon batch). How much color change is going to happen off of that 6 oz of stout in your new batch of 640 oz of pale ale?
Experience: I have been doing runs on the same yeast cake to be cheap and to use what I had. This fall was (on S-04) stout (SRM 24) to octoberfest ale (SRM 10) to Holiday Spice (SRM 17) to Pumpkin (SRM 12) to ESB (SRM 15?). This was a progression of siphon to keg (or secondary for the pumpkin), dump in new batch.
Not only was there no discernible effect on the color, there was no discernible carry through of any of the spices.
I have in gone from a stout on notty to a haus pale and found no significant effect.
Is this the best method? No. Does it work? Yes. I have taken to planning groups of beers around a yeast cake... it is efficient for my brewhouse. My consumers have zero complaints. And it is VERY cost effective.
I wash some yeast (water... no acid yet!), but I find my serial pitches very effective. I do ferment cool (low 60's) and I hit with some yeast nutrient on the 5th pitch (which DOUBLEd the size of the trub/cake that batch).
So I would encourage those who have the inclination to line up a few beers on a yeast cake and try this. It works.