system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come ice cream is soft when frozen but after you melt it and freeze it, it becomes ice.
gpt
It has to do with the size of ice crystals.

Large crystals are uniform, and very hard.

Small crystals are just as hard, but not really connected to their neighbors. since there are so many cracks and seperate crystals as a whole the ice cream is soft.

So manufacturing wants to control the size of the crystals and prevent then from binding to their neighbors.  This is fine with two methods.

1) as mentioned in other posts, stirring the batch.  It introduced air, breaks up forming crystals, and prevents forming bonds to neighbors.

2) rapid freezing.  If you freeze the mix rapidly then the molecules don't have time to organize into perfect patterns.  And the crystals start to grow everywhere rather than just from the cold spot.

The refrozen Ice cream had neither of these, and so forms large uniform crystals with no weak spots.

Edit:. Boobs changed to bonds.   There is always an autocorrect you miss.  This was a weird one.