Honey Bee Biology
Honey Bee Biology - January 2015
Crystals in Honey As Seen Through a Polariscope: In Pictures Videos
by Dr. Wyatt A. Mangum
Honey crystallization is a concern to beekeepers who want to produce a pretty liquid product with a bright clarity, particularly for the lighter honeys. Crystallization is sometimes called honey spoilage, which is completely wrong. Crystallization might precede fermentation, a honey spoilage by sugar-tolerant yeast, which may be already present in the honey. On the other hand, as the crystals grow, the moisture content of the remaining liquid part of the honey increases, which can lead to fermentation. Often however, for minor crystallization I rarely see fermentation.
Honey is a mixture of two main sugars: glucose (dextrose) and fructose (laevulose). At room temperature honey is supersaturated with glucose. That means the honey solution has more glucose dissolved in the liquid form than can remain in that state. (It is unstable.) Consequently, some of the sugar crystallizes out in a solid form until the honey solution reaches equilibrium where the remaining glucose stays in the dissolved solution. Storage conditions influence the crystals of honey where 57 °F (14 °C) is the best temperature for growing crystals, while some early scientific research determined 41 – 45 °F (5 – 7 °C) was most effective for starting crystallization. Lower temperatures 0 °F (-18 °C ), or lower, greatly slowed but did not completely prevent crystallization (according to White in the 1975 printing of the Hive and the Honey Bee, published by Dadant and Sons). I have put generic wild flower honey in a deep freezer and still had it crystallize, although my result may not be the same for other honeys since they differ so much.
Honeys crystallize at different rates. Some honeys crystallize quickly, right in the jar after a month or so. Other honeys crystallize even in the comb. On the other hand with sage and tupelo honey, crystallization is virtually absent. The crystallization could depend on the glucose content relative to the honey’s water content or to its fructose content, given what bits of research I have seen. Still the crystallization can be a big problem for beekeepers.
Heating honey will melt the sugar crystals back into a solution. Some crystals, usually the soft finer ones, melt away with just a little heating, say putting the jar in a bath of hot water. Other crystals, more coarse and hard ones, melt with difficulty. Heating honey must be done with care so as not to damage its flavor and color, which is another subject.
On the other hand, some beekeepers produce creamed honey where very fine crystals grow in honey (see Figure 1). They usually put in fine seed crystals in batches of liquid honey to start the crystallization. Eventually the entire container of honey has the consistency of peanut butter. In that stiff semisolid form, the consumer can use a knife to spread the creamed honey on, for example, bread. Sometimes creamed honey is called honey butter.
For seeing crystals in a jar of honey, especially the fine ones, a polariscope shows them against a dark background, which filters away the glare. I think when beekeepers are serious about honey production, they should have or have easy access to a polariscope. One really cannot appreciate what could be in a jar of honey, until seeing it in a polariscope, providing the polarizing filters have been installed correctly (see Figures 2, 3, and 4). Definitely, beekeepers should use a polariscope when entering honey in a honey show, because the honey judge usually has one to see inside the lighter color honeys. Furthermore, for showing honey, one should search through many empty jars to find some that do not look weird in the polariscope and would distract from the honey. Those are your special show jars.
Perhaps the local beekeeping club could maintain a polariscope since it is a good learning tool, especially for new beekeepers. Besides detecting fine crystals, even in freshly poured honey, including unheated honey, the polariscope detects ...