I can vouch for multiple batches off a yeast cake. I do recommend raining (carboy) or scooping out with a sanitized cup (bucket) some of the yeast cake each time, as that helps reduce the volume of older trub, and perhaps more critically, after batch 3 or so, the volume of the yeast cake will eat into the space you need for the krausen.
On deck: a clone of Carolina Beer Co's Rye Stout, clone of Breckenridge's Vanilla Porter,
Secondary: Dortmunder, Hopweizen
Keg Conditioning: Dunkelweizen, Roggenbier, Okto, Ord. Bitter
On tap: Alt, Hefeweizen, Cigar City Maduro clone, Mild
Bottled: Mead, Quad Rajet, Granola Bar Braggot
Too much of everything is just enough.
- J. Garcia