Water Content

The natural moisture of honey in the comb is that remaining from the nectar after ripening. The amount of moisture is a function of the factors involved in ripening, including weather conditions and original moisture of the nectar. After extraction of the honey, its moisture content may change, depending on conditions of storage. It is one of the most important characteristics of honey influencing keeping quality, granulation, and body.

Beekeepers as well as honey buyers know that the water content of honey varies greatly. It may range between 13 and 25 percent. According to the United States Standards for Grades of Extracted Honey, honey may not contain more than 18.6 percent moisture to qualify for U.S. grade A (U.S. Fancy) and U.S. grade B (U.S. Choice). Grade C (U.S. Standard) honey may contain up to 20 percent water; any higher amount places a honey in U.S. grade D (Substandard).

These values represent limits and do not indicate the preferred or proper moisture content for honey. If honey has more than 17 percent moisture and contains a sufficient number of yeast spores, it will ferment. Such honey should be pasteurized, that is, heated sufficiently to kill such organisms. This is particularly important if the honey is to be “creamed” or granulated, since this process results in a slightly higher moisture level in the liquid part. On the other hand, it is possible for honey to be too low in moisture from some points of view. In the West, honey may have a moisture content as low as 13 to 14 percent. Such honey is somewhat difficult to handle, though it is most useful in blending to reduce moisture content. It contains over 6 percent more honey solids than a product of 18.6 percent moisture.

In the 490 samples of honey analyzed in the Department’s Technical Bulletin 1261, the average moisture content was 17.2 percent. Samples ranged between 13.4 and 22.9 percent, and the standard deviation was 1.46. This means that 68 percent of the samples (or of all U.S. honey) will fall within the limits of 17.2 ± 1.46 percent moisture (15.7 – 18.7); 95.5 percent of all U.S. honey will fall within the limits of 17.2 ± 2.92 percent moisture (14.3 – 20.1).

In the same bulletin, a breakdown of average moisture contents by geographic regions is shown. These values (percent) are North Atlantic, 17.3; East North Central, 18.0; West North Central, 18.2; South Atlantic, 17.7; South Central, 17.5; Intermountain West, 16.0; and West, 16.1.

Sugars

Honey is above all a carbohydrate material, with 95 to 99.9 percent of the solids being sugars, and the identity of these sugars has been studied for many years. Sugars are classified according to their size or the complexity of the molecules of which they are made. Dextrose (glucose) and levulose (fructose), the main sugars in honey, are simple sugars, or monosaccharides, and are the building blocks for the more complex honey sugars. Dextrose and levulose account for about 85 percent of the solids in honey.

Until the middle of this century, the sugars of honey were thought to be a simple mixture of dextrose, levulose, sucrose (table sugar), and an ill-defined carbohydrate material called “honey dextrin.” With the advent of new methods for separating and analyzing sugars, workers in Europe, the United States, and Japan have identified many sugars in honey after separating them from the complex honey mixture. This task has been accomplished using a variety of physical and chemical methods.

Dextrose and levulose are still by far the major sugars in honey, but 22 others have been found. All of these sugars are more complex than the monosaccharides, dextrose and levulose. Ten disaccharides have been identified: sucrose, maltose, isomaltose, maltulose, nigerose, turanose, kojibiose, laminaribiose, a, B-trehalose, and gentiobiose. Ten trisaccharides are present: melezitose, 3-a-isomaltosylglucose, maltotriose, l-kestose, panose, isomaltotriose, erlose, theanderose, centose, and isopanose. Two more complex sugars, isomaltotetraose and isomaltopentaose, have been identified. Most of these sugars are present in quite small quantities.

Most of these sugars do not occur in nectar, but are formed either as a result of enzymes added by the honeybee during the ripening of honey or by chemical action in the concentrated, somewhat acid sugar mixture we know as honey.

Acids

The flavor of honey results from the blending of many “notes,” not the least being a slight tartness or acidity. The acids of honey account for less than 0.5 percent of the solids, but this level contributes not only to the flavor, but is in part responsible for the excellent stability of honey against microorganisms. Several acids have been found in honey, gluconic acid being the major one. It arises from dextrose through the action of an enzyme called glucose oxidase. Other acids in honey are formic, acetic, butyric, lactic, oxalic, succinic, tartaric, maleic, pyruvic, pyroglutamic, a-ketoglutaric, glycollic, citric, malic, 2- or 3-phosphoglyceric acid, a- or B-glycerophosphate, and glucose 6-phosphate.