Honey is a sweet, viscous food substance produced by bees and some related insects. Bees produce honey from the sugary secretions of plants (floral nectar) or from secretions of other insects (such as honeydew), by regurgitation, enzymatic activity, and water evaporation. Bees store honey in wax structures called a honeycomb. The variety of honey produced by honey bees (the genus Apis) is the best-known, due to its worldwide commercial production and human consumption. Honey is collected from wild bee colonies, or from hives of domesticated bees, a practice known as beekeeping.
Honey gets its sweetness from the monosaccharides fructose and glucose, and has about the same relative sweetness as sucrose (granulated sugar). It has attractive chemical properties for baking and a distinctive flavor when used as a sweetener. Most microorganisms do not grow in honey, so sealed honey does not spoil, even after thousands of years.
Honey provides 46 calories in a serving of one tablespoon (15 ml). Honey is regarded as safe when not taken in excessive amounts.
Honey use and production have a long and varied history as an ancient activity. Several cave paintings in Cuevas de la Araña, Spain, depict humans foraging for honey at least 8,000 years ago.
Honey is produced by bees collecting nectar for use as sugars consumed to support metabolism of muscle activity during foraging or to be stored as a long-term food supply. During foraging, bees access part of the nectar collected to support metabolic activity of flight muscles, with the majority of collected nectar destined for regurgitation, digestion, and storage as honey. In cold weather or when other food sources are scarce, adult and larval bees use stored honey as food.
By contriving for bee swarms to nest in human-made hives, people have been able to semidomesticate the insects and harvest excess honey. In the hive or in a wild nest, the three types of bees are:
- a single female queen bee
- a seasonally variable number of male drone bees to fertilize new queens
- 20,000 to 40,000 female worker bees
Leaving the hive, a foraging bee collects sugar-rich flower nectar, sucking it through its proboscis and placing it in its proventriculus (honey stomach or crop), which lies just dorsal to its food stomach. The honey stomach holds about 40 mg of nectar, or roughly 50% of the bee’s unloaded weight, which can require over a thousand flowers and more than an hour to fill. The nectar generally begins with a water content of 70 to 80%. Salivary enzymes and proteins from the bee’s hypopharyngeal gland are added to the nectar to begin breaking down the sugars, raising the water content slightly. The forager bees then return to the hive, where they regurgitate and transfer nectar to the hive bees. The hive bees then use their honey stomachs to ingest and regurgitate the nectar, forming bubbles between their mandibles, repeatedly until it is partially digested. The bubbles create a large surface area per volume and a portion of the water is removed through evaporation. Bee digestive enzymes hydrolyze sucrose to a mixture of glucose and fructose, and break down other starches and proteins, increasing the acidity.
The bees work together as a group with the regurgitation and digestion for as long as 20 minutes, passing the nectar from one bee to the next, until the product reaches the honeycombs in storage quality. It is then placed in honeycomb cells and left unsealed while still high in water content (about 50 to 70%) and natural yeasts which, unchecked, would cause the sugars in the newly formed honey to ferment. Bees are some of the few insects that can generate large amounts of body heat, thus the hive bees constantly regulate the hive temperature, either heating with their bodies or cooling with water evaporation, to maintain a fairly constant temperature in the honey-storage areas around 35 °C (95 °F). The process continues as hive bees flutter their wings constantly to circulate air and evaporate water from the honey to a content around 18%, raising the sugar concentration beyond the saturation point and preventing fermentation. The bees then cap the cells with wax to seal them. As removed from the hive by a beekeeper, honey has a long shelf life and will not ferment if properly sealed.
Another source of honey is from a number of wasp species, such as Brachygastra lecheguana and Brachygastra mellifica, which are found in South and Central America. These species are known to feed on nectar and produce honey.
Some wasps, such as Polistes versicolor, even consume honey themselves, alternating between feeding on pollen in the middle of their lifecycles and feeding on honey, which can better provide for their energy needs.
Honey is collected from wild bee colonies or from domesticated beehives. On average, a hive will produce about 65 pounds (29 kg) of honey per year. Wild bee nests are sometimes located by following a honey guide bird.
To safely collect honey from a hive, beekeepers typically pacify the bees using a bee smoker. The smoke triggers a feeding instinct (an attempt to save the resources of the hive from a possible fire), making them less aggressive and the smoke obscures the pheromones the bees use to communicate. The honeycomb is removed from the hive and the honey may be extracted from that, either by crushing or by using a honey extractor. The honey is then usually filtered to remove beeswax and other debris.
Before the invention of removable frames, bee colonies were often sacrificed to conduct the harvest. The harvester would take all the available honey and replace the entire colony the next spring. Since the invention of removable frames, the principles of husbandry led most beekeepers to ensure that their bees have enough stores to survive the winter, either by leaving some honey in the beehive or by providing the colony with a honey substitute such as sugar water or crystalline sugar (often in the form of a “candyboard”). The amount of food necessary to survive the winter depends on the variety of bees and on the length and severity of local winters.
Many species other than humans are attracted to wild or domestic sources of honey.
Because of its composition and chemical properties, honey is suitable for long-term storage, and is easily assimilated even after long preservation. Honey, and objects immersed in honey, have been preserved for centuries. The key to preservation is limiting access to humidity. In its cured state, honey has a sufficiently high sugar content to inhibit fermentation. If exposed to moist air, its hydrophilic properties pull moisture into the honey, eventually diluting it to the point that fermentation can begin.
Long shelf life of honey is attributed to an enzyme found in the stomach of bees. The bees mix glucose oxidase with expelled nectar they previously consumed, which then creates two byproducts: gluconic acid and hydrogen peroxide, partially responsible for honey’s acidity and ability to suppress bacterial growth.
Adulteration of honey is the addition of other sugars, syrups, or compounds into honey to change its flavor or viscosity, make it cheaper to produce, or increase the fructose content to stave off crystallization. According to the Codex Alimentarius of the United Nations, any product labeled as honey or pure honey must be a wholly natural product, although different nations have their own laws concerning labeling. Adulteration of honey is sometimes used as a method of deception when buyers are led to believe that the honey is pure. The practice was common dating back to ancient times, when honey was sometimes blended with plant syrups such as maple, birch, or sorghum and sold to unsuspecting customers. Sometimes, crystallized honey was mixed with flour or other fillers, hiding the adulteration from buyers until the honey was liquefied. In modern times, the most common adulteration ingredient became clear, almost-flavorless corn syrup, which when mixed with honey, is often very difficult to distinguish from unadulterated honey.
Isotope ratio mass spectrometry can be used to detect addition of corn syrup and cane sugar by the carbon isotopic signature. Addition of sugars originating from corn or sugar cane (C4 plants, unlike the plants used by bees, and also sugar beet, which are predominantly C3 plants) skews the isotopic ratio of sugars present in honey, but does not influence the isotopic ratio of proteins. In an unadulterated honey, the carbon isotopic ratios of sugars and proteins should match. Levels as low as 7% of addition can be detected.
In the United States, according to the National Honey Board (an organization supervised by the United States Department of Agriculture), “honey stipulates a pure product that does not allow for the addition of any other substance… this includes, but is not limited to, water or other sweeteners”.