low carb buttermilk substitute

[mere150]

Anyone know a good substitute for buttermilk? I have a Christmas party this weekend where the temptations will be greater than anything I have dealt with so far. Italian Cream Cake (grandmothers recipe), Buttermilk Pie, Oreo Cheesecake, and who knows what else. I thought if there is a way to substitute buttermilk I could make myself the Buttermilk pie filling (served more like a custard).

[feemia]

I use sour cream.

[Naja]

Powdered buttermilk can give a nice flavor, but it isn't what I'd call low carb. Probably the best substitute in a recipe would be a lot of unflavored whey protein powder plus a small amount of sour cream and a very small amount of powdered buttermilk.