I recently discovered that honey stored in containers with the comb does not seem to crystallize (or certainly not as fast as when stored without). What is the mechanism that causes this? Is there a real downside to storing with the comb?
Bees add enzymes to honey that prevent crystallization. These enzymes are destroyed by many of the processing techniques, like heating, but such techniques also physically destroy the comb, so they're not used on the honey that is in the comb.
This type of honey is also called
raw honey sometimes.
As a side note, crystallized honey is fine for consumption. If you want to get rid of the crystals you can easily do so by heating the jar a bit.
Honey, technically, never spoils. They have found it in the Egyptian tombs and it's still "good."