Thanks guys. My 3/8" bit corded power drill is 15+ years old (3V, ?A)--it is definitely a light duty, "around the house" type of drill. I can generate more torque with a regular screwdriver and my hands. It cannot turn the rollers even with a wide gap between the rollers. I just wondered if someone knew what minimum power (6 V, 12 V, 18 V) would be needed before I go out and buy one.
Edit: I have a Skil 6225 3/8" corded drill, 120 V, 3 Amps, 50-60 Hz, 0-2500 RPM, variable speed, reversing, 1/3 HP. It worked OK for making a hole (using a step drill bit) in the boil kettle. But it can't do the BarleyCrusher.