Yes a good reason to harvest after the mainflow or individual flows. Or sort combs. Mixing in the fall flow will almost always cause your entire harvest to crystallize. Or atleast around these parts. The honey I harvested in May-June has not crystallized after 2 years.No, it is the ratio between the different sugar types: glucose, fructose and saccharose. It is only glucose that hardens. The more glucose the faster the honey crystallizes and the harder it can get.