To make and pack up to 4 quarts of ice cream, you will need about 15 pounds of crushed ice and either 4 cups of table salt or 6 cups of rock salt. Refer to the table below for more information. Wash the beater (often referred to as the "dasher"), top and cream can well before using.
Then, is there a difference between rock salt and water softener salt?
Sidewalk salt is also known as rock salt. It's unprocessed sodium chloride taken directly from the ground. Softener salt doesn't melt ice any faster than sidewalk salt. But using sidewalk salt in a water softener will cause big problems.
Why do you put rock salt in an ice cream maker?
Adding salt lowers the freezing temperature of the water and for wintery roads, it means that the water won't freeze as easily. For our ice cream, it allows the temperature of the mixture around the ice cream to get colder.