- Author: Kathy Keatley Garvey
That incongruous belief that “Honey is bee vomit” is resurfacing on a number of YouTube channels, opinion pieces and other Internet posts. It's usually said with great glee: “Honey is bee vomit! It's bee puke! It's bee barf!”
Is it #FakeNews?
We asked noted honey bee guru Eric Mussen, Extension apiculturist emeritus at the University of California, Davis, whose career in bee education spans four decades, to settle the issue. Although he retired in 2014, he keeps active. Last year he completed a term--his sixth--as president of the Western Apicultural Society. He maintains an office in Briggs Hall.
And he continues to answer questions about bees and honey.
“As for the bees and vomit issue, the explanation requires quite a bit of knowledge,” Mussen says. It's about an "expandable pouch called 'the honey stomach' (which we humans do not have) and a valve called the "proventriculus" (which we humans do not have)."
“As most people know, honey begins as a dilute sugar solution secreted by ‘nectaries,' sugar syrup-secreting glands which are located in flowers or in extra-floral nectaries,” Mussen explains. “Pollen is not a natural constituent of nectar. The nectar is sucked up by honey bees and it passes into an expandable pouch called the ‘honey stomach.' This is the pre-digestive part of the part of the digestive tract that honey bees use to bring water and nectar to the hive. In honey bees and other insects, this ‘crop' precedes the portions of the digestive tract used for digesting food. There is a unique valve between the crop and the ventriculus (midgut), called the ‘proventriculus,' that has rake-like projections that constantly pull particulates, like pollen grains, from the crop contents and push them along for digestion.”
“Then the film is again exposed to the air. That process repeats itself until the moisture content of the syrup falls below 20 percent. Evaporation is influenced significantly by the relative humidity. Since honey will ferment at moisture contents above 20 percent, it is important to leave the honey with the bees until it can be immediately processed in locations with high humidity. That honey will seem to be thin. During the summer in California, the ambient relative humidity is quite low--15 percent or less. In that case, honey produced in the Central Valley can have a moisture content of 13 to 13.5 percent. That honey is quite thick.”
As an aside, “pollen grains are likely to be found in honey,” Mussen says. “Wind-blown pollens can fall into flowers that are open faced. Pollen grains are collected by hairs on the bees' bodies. They can get onto the mouthparts and become consumed with the nectar. Nectar-processing bees may have eaten some pollen in the hive before processing the honey. This is how the pollen grains get into honey. They do not necessarily get consumed with the fresh nectar. Physical contaminants of honey have to be quite small, like pollen grains, since the bees ingest all their food by drinking it through a straw-like proboscis with a very small opening at the tip. Most of the physical contaminants are removed by the proventriculus.”
And here's the point: “Since honey never is mixed with digesting food in the intestinal tract, it is inaccurate to refer to honey as ‘bee vomit.' A dictionary definition of vomit includes ‘disgorging the stomach contents through the mouth.' Since a human does not have a crop, the stomach is in direct contact with the esophagus and mouth. In a bee, the proventriculus and crop are in direct contact with the mouth. The digestion of solid foods in bees begins in the ventriculus and there is no way that a honey bee can bring that food back through the proventriculus, or ‘vomit.'
Which begs the question: Why can't we enjoy honey for what it is, not for what it isn't?
We can. Mark your calendar to attend these two events: the second annual California Honey Festival on May 5 in downtown Woodland (it's held in partnership with the UC Davis Honey and Pollination Center) and the fourth annual UC Davis Bee Symposium: Keeping Bees Healthy (hosted by the Honey and Pollination Center and the UC Davis Department of Entomology and Nematology) on March 3 in the UC Davis Conference Center. The Bee Symposium will feature keynote speaker Thomas Seeley, the Horace White Professor in Biology at Cornell University, New York.
Interested in beekeeping? UC Davis Extension apiculturist Elina Lastro Niño and her lab will teach a number of classes this spring, beginning March 24, at the Harry H.Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, UC Davis campus.
The schedule and links to the capsule information:
- Planning Ahead for Your First Hives: Saturday, March 24
- Working Your Colonies: Sunday, March 25
- Queen-Rearing Techniques Short Course: Saturday and Sunday, April 21-22 course; Saturday and Sunday, April 28-29 course
- Bee-Breeding Basics: Saturday, June 9
- Varroa Management Strategies: Saturday, June 16
- Author: Kathy Keatley Garvey
How many times have you heard that?
Strong-willed arguments flash rapidly, pointedly and furiously, much like guard bees defending their colony in the fall from would-be robbers. Just when you think the issue is settled once and for all, the arguments circle again. Non-beekeepers, in particular, gleefully maintain that the sweet mixture you spread on your toast in the morning is "bee vomit." Or they may label that spoonful of honey in your tea as "bee barf." (It's usually accompanied by "How can you eat THAT?")
So, what's the answer?
We consulted "honey bee guru" Extension apiculturist emeritus Eric Mussen of the UC Davis Department of Entomology and Nematology, who completed 38 years of service in 2014 to the apiculture industry and the general citizenry of California. (However, as an emeritus, he continues to maintain an office in Briggs Hall and answer questions.)
The answer? "In one word--No!" he says. "Honey is neither bee vomit nor bee barf."
Then, what is honey?
"To answer that question, we have to define a few important words," Mussen says. "We will use Wikipedia as our source.
- Vomit – “Forceful expulsion of the contents of one's stomach through the mouth.”
- Regurgitation – “Expulsion of material from the pharynx or esophagus.”
- Crop – “A thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion.”
Wait, there's more, and yes, it gets technical.
"While residing in the crop, a curious, pulsating valve, called the proventriculus in insects, extends curved, rake-like bristles into the crop that filter out particles from the nectar," Mussen points out. "The particles can be moderate in size to quite small, such as a pollen grains or infectious spores of the intestinal parasites Nosema apis and N. ceranae. The size is limited by the diameter of the tubular mouthparts through which all honey bee food must be consumed. Some squash pollens are too large to swallow. Once a number of particles have accumulated, they are passed back (swallowed) into the midgut as a bolus. As the bolus leaves the proventriculus, it is wrapped in a sausage skin-like wrapper called the peritrophic matrix (formerly the peritrophic membrane). Once passed into the midgut inside the peritrophic membrane, there is no way for it to return to the honey stomach."
No way. No way for it to return to the honey stomach.
Mussen says that "the most time-consuming step in converting nectar to honey is the dehydration process, during which the moisture content of the honey is reduced to a fermentation-inhibiting 20 percent or lower. To accomplish this, the nearly particle-free nectar is pumped (regurgitated) out of the crop and suspended as a thin film, hanging directly below the horizontally extended mouthparts. Bees fan the films with their wings to hasten evaporation of water. As the film thickens, it is pumped back into the crop, blended with the remaining nectar, and pumped back out to be dried some more."
So, what happens then?
"When it reaches the appropriate moisture content, the 'ripened' honey is pumped into a comb cell and capped with a beeswax cover. This is the honey that beekeepers provide for us to eat. The color and flavor of the honey depends upon the floral sources from which the nectars were collected. The moisture content of the honey is markedly influenced by the relative humidity of the ambient air surrounding the hive."
So, bottom line is this: Sorry, honey, honey is not bee vomit.
"It never reaches the true digestive tract of a honey bee," Mussen emphasizes.