Adam R. answered 11/18/13
Tutor
4.9
(8)
Physicist/Nuclear Engineer with Background in Tutoring
It looks to me like they are essentially the same thing. Though I am not a farmer, I grew up on a farm in Iowa and I've never heard the word "groat" before. I've certainly heard and used the word "grist" though. Sometimes these things are just regional and what is common in one place is never used in another. Given that you're in Iowa, I'd say go with "grist."
Tom J.
02/19/16