How important are sugar syrup ratios?

Although sugar syrup must be the simplest concoction in the history of man, it generates questions galore, many containing complex ratios, weights, and equations. When I make syrup, I simply dump some sugar in a bucket, add some lukewarm water till it looks right, and stir. When the crystals dissolve, I pour it in a feeder. Easy peasy and no math needed.

Why we feed syrup

We feed sugar syrup to honey bees in the spring to help new colonies get started, especially those that began as packaged bees. This feed gives them a leg up because instead of having to forage for a source of energy, they can eat at home and begin building a nursery right away. Colonies that barely survived the winter can also benefit from syrup.

In the fall, honey bees colonies that failed to store sufficient honey for winter (or were over-harvested) may be fed syrup in the hope they can make up the food deficit before cold weather arrives.

For generations, beekeepers have tried to help the bees along by tweaking the ratio of sugar to water in the syrup. For spring feed we try to simulate nectar by using a light syrup. In the fall we try to save the bees some work by feeding syrup with a much higher sugar content. A thicker syrup means the bees have to do less work to get it cured and capped.

Humans decided on the ratios, not bees

But here’s the catch: the sugar-to-water ratios we use are man-made conventions. The honey bees did not tell us what to provide, and they don’t carry mini hydrometers to test for specific gravity.

The sugar-to-water ratio in naturally-occurring nectar ranges from the impossibly low to super high. Honey bees prefer sweeter nectar, a preference which causes them to flock to things like apples, with nectar containing about 40% sugar, and avoid things like pears, with nectar containing about 15% sugar. But each plant has a different sugar content from every other plant, and even the weather, the time of day, and the age of the flower make a difference.

So while the honey bees are out foraging on every combination of sugar to water you could possibly imagine, well-intentioned beekeepers are home micromanaging their syrup, measuring and stirring and tweaking 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.

Guidelines are not rules

I can certainly understand using a guideline like 1:1 or 2:1 as a place to start. Those ratios are easy to remember and palatable to the bees, so there is nothing wrong with using them. But we must remember they are guidelines, not laws the bees etched on stone tablets.

These guidelines are intended to produce a syrup that resembles an “average” nectar, but averages are often theoretical. I just read that the average American woman of childbearing age has 1.9 children. But how many women do you know with 1.9 children? Furthermore, how many average woman do you know with 1.9 children?

My point is that even if 1:1 syrup was an accurate mathematical average of all nectars, it would still not represent any particular nectar in the real world. So when people tell me they tossed their syrup because they added too much sugar, or spent all night trying to figure out how to measure the ingredients to make five gallons, it is my turn for eye rolling. Close is good enough. Even not so close is good enough.

So much to learn

Beekeeping is complex and I understand that, but I think it’s strange that I receive about four times as many sugar syrup questions as I do Varroa mite questions. While miscalculated syrup is meaningless to a colony, poorly managed Varroa can destroy it. Usually, by the time I get the mite question, the colony is already gone.

It makes me wonder what we as beekeepers, writers, speakers, and presenters are doing wrong. How can we help new beekeepers sort out what is important and what isn’t? I keep thinking that explaining why—and giving specific reasons and examples—will help, but I see mixed results. Any thoughts?

Rusty
HoneyBeeSuite

A hive population wake-up call

Overwintered colonies that starve usually do so in early spring, just before the first nectar flows. In the northern climates, colonies may starve as late as April, even though everything appears green and lush.

Part of the reason is that many pollen plants bloom before nectar plants. Here in the Pacific Northwest, red alders flower early and sprinkle butter-hued drifts of pollen on car windshields and picnic tables. But pollen isn’t nectar and it doesn’t provide the sugar fix the honey bees need. Nectar-producing flowers may not appear for several weeks after those first dustings of pollen.

Then too, some of the earliest nectar supplies may be unavailable to honey bees due to inclement weather. To use another local example, big-leaf maples provide buckets of early nectar (and to-die-for honey) but in most years it is lost to spring rains that keep the honey bees inside. They can only look out their windows and sigh.

Consumption goes up while supplies go down

Aside from the weather, the annual life cycle of a honey bee colony puts it at risk of spring starvation. In the northern hemisphere, most colonies have plenty of food from the end of summer through December. During that period, the colony continues to shrink, brood rearing slows or stops altogether, and without brood, the colony keeps the nest cooler, at around 68°F (20°C). All of these factors reduce the daily food requirement.

But in the weeks following the winter solstice, the colony slowly reverses itself. Brood rearing begins again, and with brood rearing comes the need to keep the nest warmer, at around 93°F (34°C), give or take. On warmish days, the bees may venture out for cleansing flights, and flying bees use more fuel than clustering bees. On really warm days, they may actually attempt foraging, an activity that expends even more fuel.

Slowly at first, the hive population increases. Within weeks, the population gains momentum, and before you know it, there are many more mouths to feed. The food supply gets used up faster and faster as the supply gets lower and lower. It is easy to breathe a sigh of relief on that first April morning when you see your bees flowing out of the hive and playing in the sunshine. But depending on your local area, some of those colonies may not live to see May Day.

This year I took the unusual step of providing candy boards to all my colonies. Normally, I only supply them to colonies that lack sufficient honey stores. But after our unusually long, dry summer and parched autumn, I decided it was safer to feed everyone. With the candy boards in place, I relaxed. Bad move.

The population problem

It turns out that last Monday was a wake-up call for me. The weather was a balmy 55°F (13°C) with no rain, so I inspected every hive. What I found floored me.

My colonies are out of control. If I didn’t know it was January, I would have guessed it was May. My doubles have bees covering all twenty frames. My triples have bees covering 25 frames. Bees oozed from every seam, even along the sides. A few of the candy boards have golf ball-sized lumps of sugar remaining.

At first blush, you may think this is a good thing, but my immediate thought was, “How the heck can I keep these bees alive till spring?” In truth, I don’t know if I can. We still have two or maybe three months to get through and I’ve got about three times more bees than I had in October. Although I’ve seen this happen in the past, it was always an isolated hive or two, never an entire apiary.

Bad weather or bad management?

My first thought was to blame the weather. Okay, the weather is weird. Early in the winter we had a cold-snap that lasted about two weeks, but since then it has been warm—lots of days in the forties and even the fifties. The warm days could easily cause an early population increase.

On the other hand, I put pollen supplement in the candy boards. Normally, if I use pollen supplement at all, I don’t offer it until after the solstice. But this year, due to a poor foraging season, I put the boards on a month early. That may have been my big mistake: too much pollen too soon. I had buried the pollen patty inside the sugar, thinking that they wouldn’t get to it right away, but they excavated passages to it immediately.

Considering the alternatives

So now what? When I knock on the individual boxes, some sound dense, as though they may still contain honey. Since it’s warm, I can go in and rearrange the remaining honey frames, making sure they are above or immediately beside the cluster—except they aren’t in clusters, they are teeming mobs. Or I can go buy a pickup load of sugar, something that doesn’t appeal to me in the least. I’m still undecided.

I have to say, tiny clusters in winter worry me, but this worries me even more. I wonder where to go from here.

Rusty
Honey Bee Suite

Too early for spring
Spring is still months away. Public domain photo.

Hydroxymethylfurfural in sugar syrup

Hydroxymethylfurfural (HMF) is a naturally-occurring organic acid with the formula C6H6O3. It is often formed during the dehydration of sugars, especially fructose, and is known to be toxic to honey bees.

Much has been written during the past few years about the occurrence of HMF in high-fructose corn syrup* (HFCS), but that is certainly not the only place where it is found.

Regular table sugar (sucrose) is a disaccharide, meaning it is composed of two monosaccharides. In the case of sugar, those monosaccharides are glucose and fructose. Sugar is easily broken down into its components parts. The process is called inversion, and the resulting product is called invert sugar. Once the sugar is inverted, the fructose portion can dehydrate and form HMF.

Honey bees do it with invertase

The honey stomach contains invertase, an enzyme that inverts sucrose into glucose and fructose. Invertase by itself does not increase the production of HMF. However, the inverted product becomes acidic because the fructose donates a proton during the reaction and thus behaves like an acid.

The production of HMF from fructose can be enhanced in a number of ways. Heat, for example, increases the production of HMF. Honey that was heated contains more, HFCS that was heated contains more, and sugar syrup that was heated contains more. Acids that are used to invert sugar also speed up the process. Citric acid, vinegar, or cream of tartar (potassium bitartrate) added to sugar syrup can rapidly increase the formation of HMF. And time alone can increase HMF as well. Old HFCS contains higher levels of HMF, as does old honey.

High HMF equals high mortality

You can find many articles detailing the numbers, but basically the higher the HMF levels, the higher the bee mortality. Low levels of HMF may be such that we can’t easily recognize the increased mortality. For example, if you have a 10-15% bee mortality due to HMF, you may not notice it. But if you couple that with mortality due to mites or a pathogen, the extra bee deaths may be enough to push the colony over the edge.

I can’t say that I ever noticed extra bee deaths when I was feeding cooked fondant. I switched to uncooked sugar several years ago out of sheer dislike for the process. But when I look at the science behind the production of HMF, I can’t see any reason for heating sugar. Why take the risk? Bees are equipped to invert the sugar themselves without producing HMF.

On the other hand, is feeding old honey worse than feeding newly cooked fondant? The answer is a moving target—a complex subject with no easy answers.

Isn’t the pH of sugar bad for bees?

Related to the discussion of HMF is the often heard admonition that feeding syrup or granulated sugar is bad because the pH of sugar is about 7 (neutral) whereas the pH of honey is down around 3 or 4 (quite acidic). This argument assumes that the pH of nectar is the same as the pH of honey, but I don’t believe that is a safe assumption.

When bees process sugar syrup, they treat it like nectar, adding enzymes, storing it, and drying it. So the pH of syrup should be compared to the pH of nectar, not the pH of honey (the finished product).

Since many nectars contain sucrose, it is most likely that honey bees will make the nectar more acidic by inverting the sucrose, just as sugar syrup becomes more acidic after inversion into glucose and fructose. I don’t know the pH of nectar, although I assume there is a wide range. But the pH of nectar is the number we need to know before we can conclude that the pH of sugar is somehow harmful to bees.


*LeBlanc, B. W.; Eggleston, G; Sammataro, D; Cornett, C; Dufault, R; Deeby, T; St. Cyr, E (2009) Formation of Hydroxymethylfurfural in Domestic High-Fructose Corn Syrup and Its Toxicity to the Honey Bee (Apis mellifera). Journal of Agricultural and Food Chemistry 57: 7369-7376

Rusty
Honey Bee Suite

HMF molecule png
HMF molecule

 

A no-cook candy board recipe for wintering bees

For several years I’ve been looking for a way to combine a moisture quilt with a candy board. I wrote a post about this a while back, but the board in that example contained cooked candy. I wanted a no-cook candy board for several reasons.

The first reason is that cooking sugar syrup is both dangerous and boring, a bad combination for me because when I’m bored I don’t pay attention. Not paying attention when you’re working with molten sugar at about 240 degrees F is not a good idea.

The other issue is that I keep reading articles that say cooked sugar forms high levels of hydroxymethylfurfural (HMF), especially when you try to invert it with an acid such as cream of tartar or lemon juice.

The entire “invert-the-sugar-for-the-bees” argument is kind of ridiculous anyway because honey bees do it instantaneously, thanks to the enzymes in their saliva. Lots of types of nectar have high levels of sucrose, and honey bees have no issue with this, inverting it without knowing it.

The candy board frame

A candy board made to place below a quilt could not be solid, obviously, because moist air from the colony could not be collected by the quilt if that air never reaches the quilt. Secondly, the no-cook candy board could not be flipped over because “upside down” doesn’t work well with uncooked sugar.

Debbe Krape in Delaware sent me some no-cook ideas that she collected, and then directed me to the West Central Ohio Beekeepers, where some of the ideas originated. I went to work altering the plans to make them work with my system. The following is what resulted.

The candy boards are made from baggie feeder rims (or mountain camp rims) that are about three inches deep, and a plastic queen excluder, the kind that many people don’t like. A friend told me about the excluder idea, and it seemed to be the perfect answer. Remember, the excluders are not meant to exclude queens, but simply to hold the sugar in place.

Once the feeder rims were assembled, I nailed the plastic excluder onto the bottom of the rim, adding what I thought was a reasonable number of nails along all four sides. Actually, I started this project using screws, but I didn’t have enough of the type I needed, so I just used nails instead. If I find the nails pull out from the weight of the sugar, I will go back to using screws, but so far, so good.

No holes in the frame

Note that I did not put an entrance hole in the candy board frame. Every candy board design I saw had a hole somewhere, either for an upper entrance or ventilation or both. Most recommended tiny holes that I thought wouldn’t do much good, and most had to be shielded from the candy that might block them.

Since my no-cook candy board will have ventilation through the center, and my quilt has ventilation ports, there is plenty of opportunity for air flow. For the bees—should they want an upper entrance—I simply placed an Imirie shim below the candy board. This shim has the added benefit of providing some space between the candy board and the brood frames, in case the candy board sags in the middle.

Once complete, I spread a layer of plastic wrap on the table, placed the empty candy board on the wrap, and then positioned a piece of 2×4 lumber in the center of the candy board. (No, I didn’t measure the wood; it was just a random piece I found under the saw table.) Later, when the wood is removed, the empty space provides the place where the air will flow from the colony up into the moisture quilt. Some of the moisture will condense on the underside of the candy board, which is a good thing because moisture on the surface of the hard candy allows the bees to consume it with ease.

The pollen supplement

The next thing I did was prepare the pollen supplement. I decided to add the pollen supplement (as others have recommended) so that as spring approaches the bees will have an ample supply for brood rearing. Here, where we have so much spring rain, it is often hard for the bees to get out and forage for early pollen. But it was important to me to have a free choice patty—free choice meaning the bees can eat it if they want to, but they are not forced to eat it. If the pollen is mixed uniformly into the candy, the bees are more or less compelled to eat it even if they don’t want to.

I made each pollen patty from 100 grams of Mann Lake Bee-Pro pollen substitute, 200 grams of baker’s sugar, and 105 ml of water. I like baker’s sugar (also known as bar sugar) because the fine particle size allows it to dissolve quickly. Baker’s sugar in small quantities can be expensive, but in the the 50-pound bag, I pay only 2 cents per pound more than regular sugar, which is totally worth it.

At first the mix looks dry and crumbly, but I just knead it like bread for a minute and it makes a silken patty with the consistency of bread dough. You can make them in advance and they stay moist if wrapped in a piece of plastic wrap.

The no-cook candy

I decided on ten pounds of sugar per candy board based on talking to beekeepers in similar areas. I’ve heard seven pounds isn’t enough, 15 pounds is too much, so I arbitrarily decided on 10. I think most of my colonies should get by on their own honey stores anyway, but the candy board is an insurance policy of sorts and not designed to replace all their food. The feeder rims I used are plenty deep, and I think they could hold 25 pounds, depending on what you need in your area.

I placed ten pounds of baker’s sugar in a pot and added 10 tablespoons of water. Some folks recommend much more water, but one tablespoon per pound worked perfectly when I used the baker’s sugar. I don’t know if it would act differently with regular sugar, but you can experiment. Start with a small amount and add more if necessary, but remember the more water you add, the longer it will take to harden.

After adding the water, I just reached in the pot and worked the mixture by hand. I thought it would be a dry mess, but the small amount of water was amazing. It reminded me of the texture needed to build a sand castle that will hold together without slumping. It also reminded me of really dry snow that barely works for a snow ball.

Once mixed, I spread a layer on the bottom of the candy board, divided the pollen patty and put a piece on either side of the wood, and put the rest of the candy on top. Then I just tamped it down until firm.

By next morning the thing was hard as a rock. I removed the wood from the center and placed the candy on a hive. Just above the brood box I added the Imirie shim with the opening in front, then the candy board, then the quilt, then the lid.

The excluders nobody likes

I always hear stories that honey bees will not go through plastic excluders, so after a few minutes, I lifted the quilt for a quick peek. The central area was crawling with bees that hadn’t seemed to notice the excluder. I think it must be a psychological barrier more than anything: if you have to go through an excluder to do to work, that’s one thing; but going through to feast is something else again. Go figure.

So that’s where I am on the project. I have no results to report, no findings to share. But I do feel better having backup food on the hives, especially since our hot and dry summer produced very little in the way of nectar. I will keep you posted.

Rusty
Honey Bee Suite

Nails-through-queen-excluder
I just ran nails through the plastic queen excluder and into the wooden feeder.
Nail-pattern into feeder
I spaced out the nails in what seemed like a logical pattern. If the nails don’t hold, I will replace them with screws.
Candy-board-on-plastic-wrap
I placed a sheet of plastic wrap on the table and then placed the candy board on top.
Pollen-sub-mixed-with-sugar
The pollen substitute-sugar-water mix looks dry, but once kneaded, it formed a nice cohesive ball.
Pollen-sub-kneaded-into-a-ball
If you must keep the pollen patties for a while before use, just wrap in plastic.
Sugar-and-water like wet sand
The sugar and water mixture feels like wet sand. Ignore the spatula and just use your hands to mix.
Pollen-patties-buried in-sugar
First I put in the wooden board, followed by part of the sugar and the pollen patties.
Pollen-covered-in-sugar
Then I covered the patties with the rest of the sugar, and patted it down firmly.
Central-ventilation-hole
The next morning, the sugar was hard and I was able to remove the wooden board. This hole gives damp air a way to travel up to the moisture quilt.
Pollen-peeking-through the sugar
You can see the pollen patty peeking out through the sugar. This is free choice feeding: they can eat the pollen or not, depending on what they want and need.
Imirie-shim with entrance hole
An Imirie shim goes under the candy board. Besides giving the bees an upper entrance, the shim provides extra room in case the candy board sags in the center.

 

What’s wrong with this picture?

While cleaning out my shed, I discovered several hard sugar cakes which I had removed from my overwintered hives back in February. I had thrown them in a bucket and completely forgotten about them. Since we are into a nectar dearth—and my honey supers are off—I decided to put the sugar cakes out in the yard for the bees to finish.

In just a few minutes the cakes disappeared beneath a teeming mass of honey bees, but no one seemed to be fighting. The bees were just gorging themselves on the windfall, so I took a couple of photos.

While looking through the camera, however, I realized they weren’t all honey bees. Right in the center were two bumble bees of two different species.

I watched these bees throughout the afternoon. The honey bees and the two bumbles crawled over each other eating, grooming, flying off, coming back, and eating some more. They had no animosity toward each other at all. When I finally went in for the night, they were still out there and the sugar was almost gone. Bees never fail to surprise me.

Rusty
HoneyBeeSuite

Bees-on-a-sugar-tray
Now that we’re in a nectar dearth, the honey bees are eager for something sweet. © Rusty Burlew.
Bees-on-a-sugar-tray-cropped.
It seems that honey bees are not the only ones willing to take a hand-out. © Rusty Burlew.