By: Ann Harman
This article originally appeared in the Autumn 2016 issue of BEEKeeping Your First Three Years
What’s on the menu?
Sugar
It makes no difference whether you took some beekeeping classes, or worked with a mentor or read some books for beginners, you found that bees might need to be fed under a variety of conditions. Feeding bees sugar when they need it, whether as syrup or another form, is important to produce and maintain that strong, healthy colony that will survive and provide surplus honey and pollinate crops.
Over the many centuries that humans have kept bees, the necessity for food was recognized. Even Aristotle (384-322 B.C.E.) wrote that if the bees ran out of food they died. Through the centuries beekeepers were warned that being greedy and taking too much honey from the bees meant the loss of those bees. Before sugar became plentiful worldwide, beekeepers would cut honey-filled combs from one hive to give to a starving colony. Today beekeepers monitor the stored honey in their hives and feed sugar when necessary. So let’s find out where sugar comes from, how bees use it and what is best for the bees.
Sucrose is the correct name for our familiar white table sugar. There are many other ‘sugars’ related chemically, each with its own name. But the one we are familiar with, sucrose, we know as white granulated sugar or sometimes table sugar. You may find other table or baking sugars on the market, but these are not suitable for bees. In fact such sugars as ‘raw sugar,’ ‘brown sugar,’ Turbinado, Demarara, and flavored sugars are actually toxic for honey bees and should never be fed to them. Neither should sugar substitutes, used to sweeten coffee and tea, be fed to bees. The
bees also cannot tolerate such syrups as molasses, sorghum syrup, light or dark corn syrup, even if diluted with water. The honey bee’s digestive system is quite different from ours.
Plants produce sugars. Green plants contain chlorophyll that, in a process called photosynthesis, initially produces glucose, known as a simple sugar. This is then converted to sucrose, the principal sugar of green plants. This sucrose is transported around the plant to the leaves and blossoms. Therefore, the sweet liquid called nectar contains sucrose as the principal sugar.
The amount of sucrose and the amount Sugar Cane of nectar varies with the type of plant. Commercial sources of sucrose are sugar cane, a tropical or warm temperate climate plant, and sugar beet, a cool temperate climate plant.
Sucrose is useless. In order to be used by bees, our bodies and also by those that eat green plants (cows, horses) sucrose must be broken down in the digestive system to the simple sugars, glucose and fructose. An enzyme is necessary for this process. Please note that if a plant is converting the sucrose the enzyme is called invertase. If an animal is converting the sucrose, the enzyme is called sucrase. The honey bee is an animal. So are we and the cows and horses. (Unfortunately many books for beekeepers will be using the wrong term.)
In bees the enzyme is found in the stomach, called the ventriculus. It is probably also in the salivary glands. In foraging bees sucrase is found in the head glands called hypopharyngeal glands. Therefore, the foragers can add the enzyme to the nectar as they are removing it from the plant. Thus the conversion from sucrose to glucose and fructose, the sugars in honey, has begun. If the bee eats some of the nectar (passes some nectar to the stomach), the sucrase in the stomach converts the sucrose.
Glucose can be used. Brains – of bees, humans, cows and horses- cannot function without glucose. It also supplies energy to muscle cells. And glucose aids all the body cell functions.
Fructose is also an energy source but the brain does not use it. Fructose is metabolized by our liver. Now it is time to meet something else that is involved not only with feeding bees but also with processing honey. Since its full name is long and complicated, hydroxymethylfurfural, it is referred to as HMF. This substance is not found in fresh vegetables (remember, they are from plants). However it is found naturally in very small quantities in cooked vegetables. HMF is formed from fructose. Cooking usually means applying heat and it is heat that causes fructose to decompose,
producing HMF.
Is HMF a problem? Yes! It is toxic to honey bees. it is not good for people either. But there is such a very small amount in cooked vegetables that it is of no concern.
Here are the sugars, separately or combined, available to us for feeding our bees: Invert Sugar that is a commercially available combination of glucose and fructose, high fructose corn syrup (HFCS) and sucrose (white granulated sugar). Let us look at each of these individually.
Invert Sugar, used commercially by bakeries, is made from sucrose by one of two different processes. One is called acid hydrolysis and in this process HMF is produced because this process involves heat. If the enzymatic process is used no heat is used therefore no HMF is formed. This process is not used in Europe.
Beekeepers may buy Invert Sugar for feeding bees but the commercial process may not be known. Therefore the HMF content is unknown. Beekeepers do make Invert Sugar but it is called fondant, a smooth-textured solid that can be formed as a patty to be placed in the hive. Fondant is made by boiling a solution of sugar and water. Most of the recipes found for this call for the addition of an acid, vinegar or lemon juice or cream of tartar (acts a an acid). The acid prevents crystallization. However HMF is formed with the combination of acid and heat.
It is possible to make a safe, uncooked slab of sucrose for Winter bee food. The minimal amount of water is ideal for Winter supplementary or emergency feeding since the bees will not have to evaporate water. No cooking or acid – no HMF!
• 10 pounds of white granulated sugar
• 8 fluid ounces (1 measuring cup) water,
Mix well.
• Shape into slabs on waxed paper or plastic
wrap.
• Allow to harden overnight.
• Remove plastic wrap to place in hive
Another popular food for bees is High Fructose Corn Syrup, HFCS, a cheaper sweetener than sugar in the U.S. HFCS is indeed made from corn. Cornstarch is hydrolyzed to glucose. Then the glucose is enzymatically changed to fructose. Now the mixture is 90% fructose and 10% glucose. That mixture is then diluted with glucose to give 55% fructose, 42% glucose. The rest is sugar Beet water. Although there are other proportions the one beekeepers use is HFCS 55.
As manufactured, ready to leave the processing plant, HFCS 55 does not contain any HMF. However, at temperatures above 113°F fructose will decompose. HMF will be formed. The higher the heat, the more HMF. The longer time exposed to heat, the more HMF. The syrup leaves the processing plant in tanker-truckloads. On a hot Summer day the syrup in the metal tank can easily be heated up and decomposition will take place, yielding HMF. If the customer stores HFCS in drums to sell, does anyone know whether the drums are sitting in the hot sun or in a shed? A beekeeper may have no idea of the history of the HFCS after it leaves the processing plant. Analysis is not economical. Therefore it is the beekeeper’s decision whether to use HFCS or not.
What about honey, the natural food for bees? Honey is a plant product. The bee only adds sucrase and evaporates water. So honey does contain glucose and fructose and a few percent of sucrose. Since honey does contain fructose can it contain HMF? Honey can after-storage for a very long time. If exposed to heat it can contain HMF but usually a very small amount. However, if scorched, indicating excessive heat, it would not be a suitable food for bees.
Do not store honey in a warm place for a long period of time. For daily use at home, store honey at room temperature. For long-term storage, store honey in a freezer. Crystallization will be significantly delayed. Remember, the ideal temperature for crystallization is 57°F so a cool cellar can hasten crystallization.
With all the choices-what should I feed when my bees need food?
Sucrose is safe. It contains only one substance – sucrose. It is incredibly clean and pure. Kept dry it will last for years and years and…umpteen years. Sucrose is completely digested by bees, leaving no residue in the gut. Therefore it makes excellent Winter food for bees.
Sugar beet
What about cane sugar or beet sugar? Basically there is no difference. Both are 99.95% sucrose. The differences are in the 0.05%. There are slight differences in the processing of cane and beet sugars. The compounds in the 0.05% are ordinary ones, found in many foods and water and completely harmless to us and to the bees. Virtually all beet sugar is GMO, while virtually all cane sugar isn’t.
What about honey? New research has found that bees do need the variety found in the various plants bees visit. They will obtain some vitamins, some minerals and other nutrients. The quantities in honey may seem small to us but the bee is small, very small. On a diet of only honey, humans would have to eat 40 pounds of honey a day to have sufficient nutrition.
Research today is being done on the structure of the honey stomach and on the beneficial gut bacteria of the bee’s digestive system. Keep up with new findings to improve the diet of your honey bees.
Weather is unpredictable. Plants depend on the weather. Bees depend on plants. If your bees need to be fed, keep the centuries-old beekeeping tradition – feed your bees when they need to be fed.
