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
Primary: Brett Saison, Brett Berliner Weisse, sLambic I, sLambic II, Pils, Dunkel, Oud Bruin
Secondary: Flanders Red I, Cab Merlot
Kegged: Porter, Scottish 80, Pils, Orange Blossom Mead