I thought I could tell you in a second until a poster on the SF board called Foster's Freeze frozen custard.
I was about to explain that frozen custard is richer and has eggs and that Foster Freeze was soft-serve ice cream and not frozen custard.
Looking to back up my statement with some facts on the web ... quelle horror ... it seems I really don't know what frozen custard is.
I mean, growing up on the East Coast, I always considered Carvel frozen custard and Dairy Queen ... not. When I travel in the Mid-west, that rich decadent eggy soft ice cream is frozen custard to me ... and they call it that.
However, places that sell frozen custard talk about the method and temperature as well as the ingrediants.
Frozen custard supposedly has little "overrun", the air beaten into the custard. It is not held in the custard machine, but mixed, extruded into buckets and held at a temperature of about 20 degrees.
Also, reading this article about frozen custard and a shop called Custard Beach makes me think I have never tasted real frozen custard ... or at least not real quality frozen custard.
Interesting story about how Carvel came up with the idea for soft-serve.
So is frozen custard just the government definition - ice cream with eggs? Or is it more?