It’s hard to calculate how long it will take to roast them without knowing the size of the roaster and how the potatoes will be arranged. If you are able to arrange the potatoes in one layer in the roaster, they should finish baking between an hour and an hour and fifteen or twenty minutes. The potatoes should not be chilled and should instead be stored at room temperature so they don’t have to get warm before they start to bake. Bake them without wrapping them in foil—wrapping them slows down the baking process. Once the internal temperature of the potato reaches 210 degrees F, they’re done baking.

Update: I tested the roaster out with a 10-pound bag of No. 1 spuds. There were 29 in the bag and I cooked them in the roaster for around an hour and 45 minutes. They turned out perfectly!

Ten pounds in the roaster oven.