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Brewer’s yeast or baker’s yeast for bees?

Here’s a question that pops up this time of year: “Can I substitute baker’s yeast for brewer’s yeast when I’m making pollen substitute?” Truth is, I don’t know what the “official” answer is, but here’s my take on the best yeast for bees.

Both baker’s yeast and brewer’s yeast are the same species, Saccharomyces cerevisiae, but they are different strains bred for the characteristics that bakers or brewers want. Basically, these yeast feed on sugars and produce carbon dioxide and alcohol. In the end, your beer is carbonated and your bread rises. The alcohol remains in the beer but cooks out of the bread.

Dietary brewer’s yeast is dead

The brewer’s yeast that is commonly sold as a dietary supplement is a by-product of the brewing industry. It is the dead yeast that remains after the brewing process is complete, and it is sold as a dietary supplement because it is high in nutrients. Ironically, it is especially high in the b(ee) vitamins. These nutritious, but dead, bodies will not cause fermentation.

The sludge you see at the bottom of an unfiltered beer is made of little yeast skeletons that are super good for you, so always tip up that bottle.

I should mention that you can also buy live brewer’s yeast for brewing, but that is much more expensive than the big containers of dead yeast commonly available. Yeast for starting a batch of beer is usually packaged in small units and sold at specialty stores, so you’re unlikely to buy it by mistake.

Baker’s yeast is alive and well

The baker’s yeast that you find in the grocery store is live yeast, meant for making raised baked goods. If you were to add live baker’s yeast to a pollen patty that contains moisture and sugar, your patty might begin to ferment, producing carbon dioxide and alcohol in the hive.

Nutritionally speaking, both baker’s yeast and brewer’s yeast are essentially identical, and we know that honey bees can withstand high levels of carbon dioxide. But we also know that honey bees can become intoxicated from imbibing too much alcohol.

Most likely not a problem

However, if we assume “the dose makes the poison,” I think we would find the amount of alcohol produced by the pollen patties to be negligible. First off, conditions for fermentation inside a hive are not ideal, and secondly most of the alcohol will evaporate in the warm confines of the hive. If the fermentation really got going, however, the patties might lose much of the sweetness that makes them attractive to honey bees in the first place.

In my opinion, using baker’s yeast would not be a catastrophe. Certainly if you already made patties with it, I wouldn’t pull them out of the hive. On the other hand, I think it makes good sense to use the right ingredient for the job. If you use dead brewer’s yeast, you will save money over buying live yeast, and you don’t have to worry about fermentation or buzzed bees.

Honey Bee Suite

Save baker's yeast for baking and use brewer's yeast for bees.
Save your baker’s yeast for baking and use brewer’s yeast for bees. Pixabay public domain photo.

Pollen feeders for honey bees

I was recently reminded of pollen feeders when I received a photo from Tammy Sill in Rhode Island. She said of her bees, “They roll in it like dogs on dead fish!!!” I have to agree. A good and plentiful source of autumn pollen will cause to bees to frolic as if they died and went to pollen heaven.

tammy-sill-bees in pollen
Honey bees frolic in a pollen feeder. © Tammy Sill.

Tammy’s photo reminded that another beekeeper, Naomi Price of central Oregon, has been experimenting with pollen feeding for a couple of years. She says that watching honey bees collect pollen from a feeder is an education in itself.

Feeding pollen in Oregon

Naomi and her husband had been worried about the fall supply of pollen because central Oregon’s weather pattern changed over the last few years. “We have had warmer than normal autumns that have little to offer foraging honey bees, hence they use up their valuable stores.”

She opted to purchase two pounds of bee-collected pollen from a highly-recommended local source. They ground the pellets into a powder and fed it back to the bees in an inexpensive homemade container. “It was more important that the bees be given the protein immediately rather than to worry about the human eye appeal of the pollen feeder,” she said of the plastic feeder. But the design worked perfectly and they continue to use it.

The main drawback was the expense of the pollen. “Oh well,” she said of the money. “The education was worth every penny spent for a good cause…Watching the honey bee carrying pollen is every beekeeper’s ah-ha moment.”

It turns out that the bees really packed it away. “My long hives usually store 2½ frames of pollen,” she said. “However, this extra pollen pushed the storage to 4+ frames.”

A simple pollen feeder

The following photos provided by Naomi and Larry, explain their ingenious system.

Bee-collected pollen
I started with two pounds of pollen from a reliable source.
Pollen in coffee grinder
It is best to grind small amounts of pollen pellets to produce dust that honey bees can forage. Here we used a coffee grinder.
2 liter plasic bottle
Select a container with a detachable and secure lid such as this two-liter plastic bottle.
Bottom cut from bottle
Cut out the bottom of the container to be used as the entrance and exit. Blue tape protects the rough-cut edges and presents a flower bull’s eye to the honey bee.
Bottle wrapped in tape.
The container needs to have daylight blocked so the honey bees can find the exit.
Drilling hole in tree truck
Larry used a screw to secure the container’s cap to a Juniper, upwind of the hive. Remember, honey bees usually fly into the wind because a slight breeze brings them fragrant forage information.
Installing feeder
The container can then be screwed into the lid. This container gives the pollen protection against wind and unexpected rain.
Filling the feeder
The container is loaded with a GENEROUS amount of dust. Remember, pollen is of no value to the honey bees if it is sitting on your refrigerator’s shelf.
Bees enjoying the pollen
We removed the feeder at night and brought it into the house to prevent moisture absorption by the pollen. We re-ground any dust left in the feeder and added it back the next morning. Our bees consumed 1# in three days. Most hives were bringing in three colors of pollen plus the offered pollen dust.
The second year we used the same type of container because they are easy to put up and take down. However, we added color to the outside instead of tape. We found the most important thing was to install the feeders upwind of the hives.

My own experiment was a “cat”astrophe

After reading these accounts from Naomi and Tammy, I was eager to set up my own experiment. So last week I placed three containers on the picnic table. One contained only pollen substitute, one contained a mixture of trapped pollen and pollen substitute, and the third contained only trapped pollen.

Once I was satisfied with my mixtures, I went to look for some tools. When I returned about five minutes later, the bowl of plain pollen substitute was empty. “What the?” I said aloud. Then I saw my cat doing this thing with her tongue. She was sticking it way out and scraping it against her teeth. Tongue, whiskers, and nose were dusted yellow and I thought she was going to choke to death. Who knew pollen substitute was such a yummy treat?

Honey Bee Suite

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?


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.

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

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HMF molecule png
HMF molecule