In 3.5 Prestidigitation is used mostly as a "flavor" spell. However, I noticed that in Next they added a new use for it.
You instantaneously light or snuff out a candle, a torch, or a small campfire.
PHB 267, under the uses of Prestidigitation.
Now given the flammable nature of Grease in our game, can Prestidigitation actually be used to ignite the Grease?
I'm currently DMing the game and my player pointed this out. Currently mulling to rule that it won't but I don't like shutting down ideas like this without a better reason than just "I don't like it".