Why Does Old Ice Cream Get Crunchy?

This was originally posted on Sustainable Nano, which is my new project.  You should go check it out!  Science Minus Details will live on though! Poop posts will come, have faith!!!!

As with all good meals of information, let's start this one off with ice cream!

In an effort to grow out of my "slim fit" clothes, I've begun an ice-cream-after-every-dinner diet.

Even the cat likes my diet!

An added bonus is that I go through jugs of ice cream so quickly that I NEVER have to deal with old, gross, crunchy ice cream! You know what I'm talking about. You reach into the back of your freezer, find that jug of 6-month-old ice cream, only to discover that it tastes like the perfect mixture of sugar, fat, and sand.