I don't do 10-gallon batches, but I use a Koelsch/California Ale yeast blend for my Apfelwein fermentations. I don't have the equipment to see how they are behaving, i.e. whether one strain has become dominant, but the results are very enjoyable. I just keep reusing the same yeast cake. I am sure it'll eventually need washing, but thus far I haven't had any problems with autolysis or other yeast breakdown-related off-flavors.
The Fiesty(sic) Goat Brewery est. 2007 & Clusterfuggle Experimental Ales est. 2009
Planned: sLambic II, Flanders Red II
Primary: Fat Man Porter, Orange Blossom Mead, sLambic I
Secondary: Flanders Red I
Kegged: 3 different ciders, Janet's Brown, Barrel-aged Stout, Hallertau Blanc Pale Ale
Bottled: Flanders Red I