Honey
Many thanks to Alicia Normand for submitting this article.
 A worker bee inspects the honey stores.
HONEY is a substance produced by bees from nectar or honeydew that they collect from living plants, which they transform by evaporating water and by the action of their own enzymes. These enzymes are: invertase, glucose oxidase and amylase (diastase), and come from the hypopharyngeal gland.
When the forager returns with the nectar she passes it to a house bee who also adds her enzymes and starts the first stage of changing it to honey by repeatedly unfolding and folding her proboscis thus exposing a drop of liquid to the air. She then sucks it back into her mouth. This can go on for up to 20 mins. Eventually she deposits it in a cell, already minus some of the water content. Further evaporation takes place by fanning with the wings and hanging drops of nectar up to dry in the hive.
Major constituents of honey
Water average 17%
Fructose 39%
Glucose 32%
Sucrose 2.3%
Other sugars
Disaccharides
Also: acids, minerals, nitrogen, enzymes, aroma constituents and other substances.
Granulation (thickening) occurs as the honey is stored at temperatures lower than in the hive. It can occur very rapidly as with rape or it can take years as in some tree honeys. The rate depends largely on the relative amounts of fructose and glucose - most honeys having slightly more fructose.
Those that have about 1½ times the fructose may never granulate eg. False Acacia from many regions, Tupelo and Sourwood from North America
A few contain more sucrose and granulate very quickly eg. Rape, Dandelion and Ivy. Ivy has 70% glucose and 22% fructose & 1% sucrose.
In Tasmania the honey from Leatherwood trees granulates so firmly that it is poured into moulds then sold in blocks wrapped in paper.
Those that granulate quickly are usually of fine crystals giving a smooth honey whilst slow granulation produces large crystals giving a crunchy texture.
Viscosity
This is controlled by the water content and temperature of the honey. High water content gives a thinner honey while low water content makes it quite thick & sticky.
Not all honeys are liquid. Honey from the Ling heather is called thixotropic which means it is a gel. This gel can be made liquid by stirring but it will return to a gel later.
It can be identified in the jar by the dark colour and the bubbles of air it contains. It also has a distinct, strong flavour with a slightly bitter aftertaste.
Fermentation
Fermentation can occur if the water content of honey is too high. Honey is hygroscopic which means it will absorb moisture from the atmosphere. Stored honey is especially liable to ferment as the temperature rises in the spring if the water content is above 18% as yeasts are always present. Best to keep it below 11ºC.
Aroma
Some of the substances that give honey its aroma are common to all honeys but some come from the plant source. All are volatile and evaporate at high temperatures.
Colour
Minerals are among the components that affect colour and the range is 0.02% and 1%. Very light honeys contain less and dark more.
Naturally there are exceptions and the following all contain less than 0.1% -
very light: rape, lucerne, false acacia
Light - amber: some top fruit, clover, rosemary
Dark: buckwheat
Dark with a high mineral content: Heather & Honeydew
More unusual colours:
Greyish yellow: borage
Greenish: Lime
Greenish brown: maple & tree of heaven |
