Yesterday I opened a sealed jar of raw honey (blackberry). Over the course of a not-very-long meal (at which the honey was being used as a condiment) I watched it go from liquid to crystalized. I've had honey crystalize after having been opened for weeks or months, but I've never seen it happen in a matter of minutes before. Googling led to lots of explanations and rebuttals about why raw honey crystalizes slowly, but I found nothing that addressed what I saw.
I store my honey in an interior pantry cabinet, so it's at room temperature — lately around 65-70F. (I specify interior because I've found that storing it in cabinets on exterior walls leads to faster crystallization, presumably due to winter cold seeping through the wall.) I have another unopened jar of this honey in that cabinet right now and would prefer to not have it immediately crystalize when I open it. I understand that crystallization isn't bad, but liquid works better for many uses. So I'd like to understand what happened and what I need to change to get a different outcome.
Best Answer
Crystallization involves two stages: nucleation (the formation of the crystals, either spontaneously, influenced by solids like the walls of the container or a foreign substance, or influenced by existing crystals) and growth (where the size of crystals increases from microscopic).
Nucleation is most likely to occur when there are impurities in the honey around which crystals can form, or there are existing crystals of honey (which may be very small). Impurities could be introduced from the air or more likely on a spoon or stirrer, and existing crystals can easily form on the walls of the container or at the opening. Stirring brings these into contact with more of the rest of the honey, enabling more nucleation to take place.
As for the growth rate, my instinct is that this will depend in a complicated way on factors like the specific composition of the honey, the temperature, air pressure and perhaps even humidity of the surrounding air. In your case, it seems that the conditions were perfect for secondary nucleation and crystal growth, so as soon as an initial crystal appeared the whole jar quickly crystallized (similarly to how supercooled water will freeze suddenly when nucleation is triggered).
In terms of your second jar of honey, all I can recommend is:
It's also worth saying you can get crystallized honey back to a liquid state by heating gently (I use a microwave for short bursts; be careful as it can get very hot and remains sticky – you do not want to get it on you!); because of the residual crystals on the container it tends to crystallize again within a few days but it's useful when you need it.