Tuesday, November 29, 2011
Why Does Honey Crystallize?
Here's Wikepedia's description of the properties of honey found at: http://en.wikipedia.org/wiki/Honey
"Crystallized honey is honey in which some of the glucose content has spontaneously crystallized from solution as the monohydrate. Also called "granulated honey."
Honey that has crystallized over time (or commercially purchased crystallized) in the home can be returned to a liquid state if stirred in a container sitting in warm water at 120 °F (approx 49 °C)."
"The physical properties of honey vary, depending on water content, the type of flora used to produce it, temperature, and the proportion of the specific sugars it contains. Fresh honey is a supersaturated liquid, containing more sugar than the water can typically dissolve at ambient temperatures. At room temperature, honey is a supercooled liquid, in which the glucose will precipitate into solid granules. This forms a semisolid solution of precipitated sugars in a solution of sugars and other ingredients.
"The melting point of crystallized honey is between 40 and 50 °C (104 and 122 °F), depending on its composition. Below this temperature, honey can be either in a metastable state, meaning that it will not crystallize until a seed crystal is added, or, more often, it is in a "labile" state, being saturated with enough sugars to crystallize spontaneously. The rate of crystallization is affected by the ratio of the main sugars, fructose to glucose, as well as the dextrin content. Temperature also affects the rate of crystallization, which is fastest between 13 and 17 °C (55 and 63 °F). Below 5 °C, the honey will not crystallize and, thus, the original texture and flavor can be preserved indefinitely.
"Since honey normally exists below its melting point, it is a supercooled liquid. At very low temperatures, honey will not freeze solid. Instead, as the temperatures become colder, the viscosity of honey increases. Like most viscous liquids, the honey will become thick and sluggish with decreasing temperature. While appearing or even feeling solid, it will continue to flow at very slow rates. Honey has a glass transition between -42 and -51 °C (-44 and -60 °F). Below this temperature, honey enters a glassy state and will become a noncrystalline amorphous solid.
"A few types of honey have unusual viscous properties. Honey from heather or manuka display thixotropic properties. These types of honey enter a gel-like state when motionless, but then liquify when stirred.
"Regardless of preservation, honey may crystallize over time. Crystallization does not affect the flavor, quality or nutritional content of the honey, though it does affect color and texture. The rate is a function of storage temperature, availability of "seed" crystals and the specific mix of sugars and trace compounds in the honey. Tupelo and acacia honeys, for example, are exceptionally slow to crystallize, while goldenrod will often crystallize still in the comb. Most honeys crystallize fastest between about 50 and 70 °F (10 and 21 °C). The crystals can be redissolved by heating the honey."
The problem with these crystals is that they aren't very pleasant on the tongue. But enter Creamed Honey/Whipped Honey and it's another product the beekeeper can sell.
In my next post we'll explore how to Make Creamed Honey.