Can store-bought (i.e. pasteurized) cream be cultured at home for making cultured butter?
I've read several recipes for DIY butter which recommend letting your cream sit out at room temperature for a few hours or overnight.
The idea is to allow naturally occurring microbes in the cream to promote fermentation, in order to add complexity to the flavor of the cream and the resulting butter.
My question is: is this even possible with store-bought cream which has been pasteurized or "ultra pasteurized"? Do the microbes necessary for cultured cream survive this process?