I'm going to use about 1/3 raw spelt in my next Saison. Almost all references I see to any unmalted grain include a cereal mash, but it seems like everything except corn and rice should gelatinize at mash temps.
My plan is just to do a beta glucan rest at 113 and then take it up to 146 or so. Anyone do this before and get bad results? The spelt will be almost pulverized in a corona mill, like I do with my raw wheat for lambics, so the starches should be easily accessible.
Edit: Also, would it be worth mashing for 90 minutes?