Table of contents
- Guidelines for making bee syrup
- The origin of the sugar syrup ratios
- Every plant’s nectar is different
- Averages can be deceiving
- Significant digits in bee syrup measurements
- Don’t bother inverting the sugar
- Inversion: honey bees just do it
- Cooked syrup and hydroxymethylfurfural
- Organic bee syrup is high in ash
- The problem with cold syrup
- “But bees can’t eat dry sugar”
- Sugar or trash? What bees think
- Don’t change, just be reasonable
- Worrisome thoughts, just for a second
After fielding beekeeper questions for eleven years, I have a decent idea of what confuses beginners. When it comes to puzzlement, nothing beats the perils of sugar syrup. Questions such as “How do I make sugar syrup?” outnumber “How do I control varroa mites?” about 2:1. And there it is, one of syrup’s revered ratios, along with 1:1, 3:2, and 5:3.
Before I begin to dismantle the concept of sugar syrup ratios, let me say there is nothing wrong with them. From a management point of view, they are just fine. Beekeepers have been using standard ratios of sugar to water since sugar was cheap enough to feed bees.
Most beekeepers have fed sugar at some point in their careers. Some do it regularly, some do it only when needed. That’s fine. I do not intend to examine the moral implication of feeding syrup to honey bees.
Guidelines for making bee syrup
The best thing about these ratios is the guidance they provide to beekeepers. A light syrup in spring enhances brood rearing as would an early nectar flow. A heavier syrup in autumn is easier for bees to process because less water needs to be removed. Conceptually, these guidelines work well and have enhanced the lives of countless colonies.
However, based on questions I’ve read, it’s obvious that new beekeepers do not understand the role sugar syrup plays in colony management. Nor do they understand how precise the measurements must be to properly care for bees.
For example, a woman recently explained how she meticulously measured the ingredients for 1:1 syrup, but before she finished, her husband swept spilled sugar from the table and dumped it in the pot, “completely ruining the entire batch!” She wanted to know if I could calculate a fix, estimating he added an entire teaspoon to the gallon of syrup.
I can only imagine the firestorm this created and hope she didn’t deploy the rolling pin on husband number whatever. But this is a typical question, along with others about reading the meniscus, sufficient stirring, using sugar beyond its pull date, chlorine in city water, and allowing syrup to sit on the counter overnight. The complexity arising from the simple act of mixing sugar into water is astounding.
Worse, the first question that usually follows these I-screwed-it-up stories, is “Will it kill my bees?” Now I’m the perplexed one. How, exactly, do they think it might kill them?
The origin of the sugar syrup ratios
I have no clue who first suggested the now-familiar sugar syrup ratios or when. Whoever did was on to something because the ratios are easy to remember and work well. But any recommendation to feed bee syrup at a specific ratio of sugar to water is a guideline, a rule of thumb, an estimation, and whoever suggested the idea was a human, not a bee. The notion of a specific sugar concentration is foreign to bees simply because it’s foreign to plants.
Every plant’s nectar is different
All nectar-producing plants have their own recipe, a genetically-driven range of sweetness. Some nectars are low in sugar, such as that produced by pear flowers. Others are high in sugar, such as the nectar from certain blackberries. Most are somewhere in between, but I doubt any are exactly 1:1, 3:2, or 2:1.
Furthermore, the amount of sugar in the nectar of each species can vary with environmental conditions. It may change from morning to evening, in overcast weather vs sunny, on hot days vs cool ones. Add to that windy days vs still ones, sun vs shade, and humid vs dry. Soil type can make a difference, too, as can soil fertility. Nectar concentration can even vary among the blooms on one plant. There is no immutable ratio of sugar to water in nectar, so why do we think sugar syrup must have a precise percentage of sugar?
The honey bees did not provide the specifications for syrup, and they don’t carry mini hydrometers to test its specific gravity. While the bees are ingesting infinite concentrations of sugar to water, we are home micromanaging their syrup, measuring and stirring and tweaking, hoping to arrive at some magical ratio that the bees don’t give a rip about. If they could roll their large compound eyes, they would.
Averages can be deceiving
Recommendations based on averages always remind me of the government. If you look at U.S. census statistics, you will find that in 1960, the typical American family (whatever that is) had 2.33 children. In 2019, the average family had 1.93 children. Now, I don’t know about you, but I’ve never met even one family with either 2.33 or 1.93 children.
The same goes for sugar syrup. Even though we swear by 1:1 or 2:1 syrup, and we go to great lengths to make accurate measurements, there’s likely not a flower in the world that produces an equivalent nectar. If natural nectar ranges from four to seventy percent sugar, how can tossing in that extra teaspoon (or cup or pound) make any difference to the bees?
Even though the guidelines are handy and work well, we must realize that they are not edicts etched in stone. Variations in measurement will not make any difference and will not affect bee health. You are not going to kill your bees with a concentration that is a little more or a little less than the guidelines suggest — or even a lot more or less.
Significant digits in bee syrup measurements
The last time I wrote about sugar syrup, I explained that you can measure your ingredients by either weight or volume. Yes, the results are slightly different. But in this application, where you’re trying to replicate a moving target, you can only approximate the composition of nectar, no matter how carefully you measure.
Since 1 cup of refined sugar = 200 grams = 7.05 ounces = a little less than 0.5 pound, and 1 cup of water = 236 grams = 8.3 ounces = a little more than 0.5 pound, you can measure by weight or volume or a little of both.
Someone responded explaining how dangerously wrong I was. And to prove it, he had taken his wife’s measuring spoons and kitchen scale and recorded everything to prove how vastly different weight and volume can be. He sent his calculations, all extended to seven decimal points, just to prove how mistaken I was.
Not only did this demonstrate a lack of knowledge about nectar and bee biology, it also highlighted a problem with significant digits. By claiming 7 decimal points worth of precision from a measuring spoon that could probably give him one, he was producing meaningless strings of numbers and completely missing the point.
Don’t bother inverting the sugar
Another popular misconception involves inversion. Many beekeepers think they must invert table sugar to make it digestible to bees, or to make it more acidic so the pH closely resembles that of honey. Neither is necessary.
Let’s back up a moment and look at table sugar. Table sugar is sucrose, a disaccharide made from a molecule of glucose and a molecule of fructose. These two molecules, both of which are simple sugars, are bound weakly together. Chemicals can be used to split the molecules apart, something frequently done by bakers who are trying to achieve certain properties in their products, such as moisture retention.
Invertase, an enzyme produced by yeast, is the baker’s chemical of choice for this job. The name describes its action: it inverts the disaccharide back into its component parts by splitting the bonds between the glucose and fructose molecules. You can also split the bonds with acid, which is what beekeepers try to do with vinegar, lemon juice, or cream of tartar (tartaric acid).
Inversion: honey bees just do it
In truth, nearly all nectar contains much sucrose accompanied by an assortment of simple sugars, including glucose, fructose, maltose, and others. But when you analyze honey, it’s mostly glucose and fructose. In other words, the sucrose the bees collected was split into simple sugars during the honey-making process.
How did that happen? Well, it turns out that bakers aren’t the only ones with a cache of invertase. Honey bees have their own supply, right in their salivary glands. When the bees scarf down nectar and hold it in their crops, invertase is already at work, breaking down the sucrose into the simple sugars glucose and fructose. The acidity in honey is produced by several other bee-produced enzymes including glucose oxidase, which forms gluconic acid during the breakdown of glucose.
When bees eat sucrose in the form of sugar syrup, the same thing happens. The bees automatically add the enzymes that invert and acidify the syrup, so there’s no reason to do it for them. “Don’t worry,” they say, “we’ve got this!”
Cooked syrup and hydroxymethylfurfural
Hydroxymethylfurfural (HMF) is a naturally occurring organic acid formed during the dehydration of sugars, especially fructose. Under laboratory conditions, HMF has proved toxic to honey bees.
Elevated levels of fructose increase the probability of HMF formation, so something like high-fructose corn syrup is known for lots of HMF. But other things, such as the inversion of sugar syrup by acids, also increase HMF by increasing the amount of fructose in the syrup. Heating syrup or honey also increases HMF, as does aging.
So how much of a problem does it cause? The numbers vary, but it seems to be a minor problem, possibly shortening the lifespans of some colony members. Cooking syrups to make fondant or hard candy is an age-old beekeeping practice that continues to this day, so the effects are not catastrophic. Still, when combined with other factors like pesticides, parasites, or pathogens, a little extra colony loss may not be desirable.
Fortunately, for those who want to avoid excess HMF, no-cook candy boards or dry feeding of granulated sugar circumvent the problem. Highly concentrated syrups, even 2:1 are harder to make without hot water, but the less heat you use, the less HMF you will create. Leaving out the acid helps too.
Organic bee syrup is high in ash
A surprising number of new beekeepers are eager to feed organic sugar to their bees to give them the best possible diet. Unfortunately, organic sugar has a much higher ash content than regular refined sugar, and a high-ash diet in winter can increase the chances of honey bee dysentery. Apparently, the ash can capture and hold extra water in the gut, which is the ultimate problem.
The higher ash content gives organic sugar a light tan color, which you can clearly see. The extra ash is due to the way organic sugar is processed. Typical refining methods use chemicals that are not allowed by organic standards, so the entire process was reimagined in order to produce what is generally called “evaporated cane juice” rather than refined sugar. The amount of ash varies by manufacturer, but when I researched one popular brand, I found it contained 2.15 percent ash compared to 0.07 percent in non-organic refined sugar, over thirty times as much.
The problem with cold syrup
Another common sugar syrup question is “Why have my bees stopped drinking their syrup?” or worse “How can I make my bees drink their syrup?” The adage “You can lead a horse to water, but you can’t make him drink” applies here. You can’t force bees to drink syrup, you can only gently suggest.
If it’s autumn when the bees stop drinking, the syrup is probably too cold. I can’t name an exact temperature when bees stop drinking syrup, but it’s somewhere around 50 F. If bees drink syrup that’s overly chilled, they go into torpor, a state of lowered metabolic activity brought on by a drop in body temperature. Once they become stiff, slow, and barely able to move, they may fail to rejoin the cluster.
For bees that work together to maintain a minimum nest temperature, this can be dangerous to the entire colony. So rather than drink the cold syrup, they just ignore it. Syrup can be kept a bit warmer by using an internal feeder above the cluster. In that configuration, warm air from the colony rises and keeps the syrup warmer. Three-season feeders work on this principle and can be used later in the fall than external feeders. In areas with cold winters, syrup should be replaced with fondant or sugar cakes during the coldest months.
“But bees can’t eat dry sugar”
As anyone who feeds sugar bricks, candy boards, or granulated sugar can attest, winter bees can thrive on granulated or hard-as-rock sugar cakes. However, the surface of dry feed needs to be moistened before the bees can consume it.
To be effective, dry feed needs to be placed above the cluster so that moisture-laden warm air can condense on the surface and dissolve it. This happens naturally due to convective currents in the hive. Moisture from bee respiration rises along with the warm air and condenses on the hard sugar, forming a thin, sticky film that the bees lap up from the surface. As the outer layer is consumed, more moist air dissolves the next layer, and so on, until the bees eat the whole thing.
Dry sugar in the wrong place, such as on the bottom board, will usually fail as a food source because it’s cold down there. Bees will move into areas that are relatively warm, and the warmest place outside of the cluster is directly above the cluster. No matter how hungry they get, bees will not move down into a colder part of the hive to get food if it means risking torpor.
Sugar or trash? What bees think
Many beekeepers insist their bees don’t like granulated sugar and, instead of eating it, they take it outside like trash. Indeed, if granulated sugar is fed in warm weather when bees are out flying, they will do precisely that. If it’s warm enough to fly, it’s warm enough to break cluster and clean house. Once the cluster has dissipated, there is no longer a steady supply of rising moisture to wet the granules, so out they go.
Listen to what your bees are saying. Dry sugar feeding is a wintertime thing, not a spring or a fall thing. If you remember that, your bees won’t haul it away.
Don’t change, just be reasonable
I’m not proposing you abandon time-honored recipes for syrup or trusted guidelines for feeding. Of course not. I’m only suggesting they are meant for your convenience, not your undoing. Lighten up and realize no bee is going to complain about your quality control or lack thereof. Spend less time worrying about exact measurements and precise recipes, and spend more time thinking about how the bees will access the feed, how cold it will get, and how edible it will be.
No bee is going to reject a source of food because it’s not made to certain specifications. Well, not usually. Honey bees are known to reject the four percent nectar (1:25) that leaks from pear blossoms, even though other species, like mason bees, seem to like it. Because they have such a high need for sugar, honey bees generally select the sweetest nectar they can find that’s conveniently located, available in a big patch, and coming from a flower that suits their tongue length. You rarely see them checking the nutrition label for sugar concentration.
Worrisome thoughts, just for a second
I was nearly finished writing this article when a horrifying thought crossed my mind. What if American Bee Journal insists on precise measurements of sugar and water, say four decimal places, or worse? Worried that I might offend the powers that be, I riffled through virtual pages of the ABJ website, looking for a hint.
Then I found it. Buried in the FAQs section are directions for making 1:1 syrup: “Half fill your container with sugar and add water to completely fill the container.” Perfect! Another reason to love ABJ.
Honey Bee Suite