Never Ending Punch

About a month ago I made this simple drink by mixing a container of rainbow sherbet with a two liter of lemon lime soda (ginger ale can also be used). After dinner there was quite a bit left over (mostly the sherbet). I dumped it into a gallon size (freezer) Ziploc bag, and stuck it in the freezer. The next week I got the frozen drink out, and poured another two liters of soda over it. When dinner was over, I repeated the freezing process. Tonight was the fifth time I have used the same frozen drink. The consistency was like drinking a slushy - so delicious. With one container of sherbet I was able to make this punch five times. Whenever I remembered I would pick up a two liter of soda, either lemon lime or ginger ale. It can even be a generic brand (usually under $1).