Making good ice cream involves letting the pasteurized and homogenised mix rest at a low temperature, around 2 to 4 degrees Celsius, for several hours before it ever reaches the freezer. During this resting period, the milk proteins fully hydrate and swell, the fat globules begin to partly solidify, and any stabilizers added to the mix get enough time to properly thicken it. All of this happens strictly before freezing begins, which is why this maturing step, called aging, is placed before freezing in the production sequence.