I would love to achieve a Grade A Milk which means that the milk is cooled to 40 degrees within 30 minutes. Unfortunately, I am at a grade b level which is 48 degrees in 30 minutes using an ice water bath and trying to stir the water/shake the milk throughout the 30 minute process. I was wondering if anyone knows of a product that can be used besides the commercial bulk cooling tank to get the milk cooler. Some kind of ciculating something. I have tried to set the bucket inside a container with ice while I milk, bucket floats, what a mess trying to get it into the small hole! It still only got it to 48 degrees althought there is no foam which is nice. I will try the rock salt if you really think that would make a difference and bring me to the 40. How much would I use?