How to Make Homemade Ice Cream in a Plastic Bag?

Making homemade ice cream in a plastic bag is to seal the milk, vanilla flavor and sugar in a quart-size plastic zipper bag, making sure to squeeze out as much of the air as possible. Fill a gallon-size bag with crushed ice and nestle the first bag of mixture in the ice. Then sprinkle rock salt on the top of the ice then seal the bag tightly and shake and gently squeeze the bag, making sure the inner bag is constantly surrounded by ice during the process. Check about every 5 minutes for the ice cream.