I saw a fondant tutorial where a BC crumb coat wasn't used - she just used corn syrup to make the fondant stick. Has anyone heard of this or tried this technique?
Advantages or disadvantages? I imagine the cake wouldn't be as tasty or creamy?
Personally if I had to choose I would use a jam instead. Pure corn syrup sounds a bit much.
BC from scratch is my #1 crumb coat - you get such a nice firm set that the fondant does not need to be worked much.
If you take apricot or another clear jam and melt it down to a syrup this taste nice as well.
Part of the crumb coating under fondant is to give you a nice smooth base to work on. If you have torted or have two cake layers on top of each other and there is a seem it will show under the fondant. That is why you often see some sort of icing under the fondant.
I use corn syrup under fondant on cake dummies. It does stick it to it, so if you are starting a smooth surface you could try it.