"These experiments show, as have those of others, that ultrasound has an effect on nucleation resulting in finer more uniform crystals." [1]

"High powered ultrasound can assist the crystallization process in several ways, as it can influence the initiation of crystal nucleation, can control the rate of crystal growth, ensuring small and even-sized crystals are formed" [2]

Hmm. Anyone with an ultrasound device want to try to make some icecream?