I just use my electric drill with a paint mixer attachment, like https://www.homedepot.ca/product/a-richard-paint-mixer-16in-... and I've only had one spray incident, when I forgot to hold on to the jar while running the drill. It was epic!
He makes peanut butter by the ton. Loading the hopper was quite tricky and getting up and checking a bit fraught. Knowing how much peanut butter is in the big vat thing once it is being stirred is quite hard too, and most sensors become less accurate once coated in peanut butter.
His ultrasound sensor (measuring the distance to the surface of the peanut butter) is a thing of beauty. He used Arduino.