The only potential problem I can see may be the size of the holes in the drum. Too big and some of the malt could pass through the holes or get stuck in them which would be just as bad. Other than that, the concept is sound. I've got a roaster with a glass drum that I've been thinking about trying this with. Randy Mosher talks about toasting your own malt in, "Radical Brewing". You can also roast grain in a wok or skillet. I've done it on a cast iron griddle over a turkey fryer burner. Won a best of show years ago using some home roasted malt. Keep in mind that you won't typically be using much of the roasted or toasted malt in your grain bill, so that big coffee roasting drum might be overkill. Even for home roasting coffee it's a little too big. It's better to roast smaller amounts more frequently as coffee only stays fresh (at its peak) for about a week. Five pounds at a time is a lot of coffee for home use. I use only about a pound a week.
