Best Answer
The quicker you freeze something, the smaller the crystals. This is why in cryogenics, as well as in the frozen seafood business, they freeze things as rapidly as possible. Ice crystals damage cells because they are like knives that rip through cell membranes. But if you can freeze something quickly enough, the ice crystals can be smaller than the size of a cell and they may not damage or rupture the cell membrane. If you freeze a slab of meat or fish really slowly, it will be like a limp sponge when you thaw it back out, but if you flash freeze it by dipping it in liquid nitrogen, it will thaw back out like a fresh piece of meat.
That's basically true for all crystals. Whenever you see large crystals, whether it's in beautiful gemstones or in rock candy, those formed over longer periods of time than small crystals, like in granulated sugar or fine-grained igneous rocks.