Water ganache is ganache made with water instead of cream. The taste is still just as good but with no added dairy. You might make water ganache for a few reasons. Maybe you ran out of cream, maybe you have cottage laws in your area that prevent you from using fresh dairy. Maybe you’re looking to make a vegan version of ganache. Whatever your reasons are, water ganache acts just the same as regular white chocolate ganache and is great for making those pretty drip cakes.