simplest clutch...V-belt but...dissipate a lot of heat.
The slippage and heat will degrade the belt and create lots of little beads of rubber that will get down into the honey....ick.
bluebee the snowblower transmission you speak of would not last at all in a slip situation. The rubber friction wheel would wear out in no time flat.Wrong.
It doesn't have to slip.
Dadant made just that kind of speed control decades
ago for all sizes of extractors.
One difference-the large wheel was on the end of the basket shaft.
The small rubber drive wheel moved across the surface of the shaft wheel.
Fill the basket, make sure the adjustment has the drive wheel on the outer edge of the basket disc, start the basket spinning by hand, flip the electric switch, wait a little for the weight to balance and move the lever to push the drive wheel across the flat wheel and gradually increase the speed of the spinning basket.
When it is spinning as fast as you wish leave it to spin until your done, then turn it off and let coast to a stop or use the hand brake.
Parts are still available.
No fancy electronics.
I have an old self-propelled lawn mower with a very similar variable drive. Works great, goes years without parts replacement.
Adapting some snowblower parts may work just great, especially if free!