bee biology

Why does this bee suit smell like vomit?

I don’t get many emails from, so the ones I get tend to attract my attention. What does the state of North Dakota want with me this time? I wonder.

The sour smell of curdled milk

It turns out the message was from the curator of a history museum, and his question concerned a smelly bee suit. He explained that the museum had recently accepted a donation of a used beekeeper’s suit, but the staff was disturbed by the powerful smell. The curator described it as “baby spit up—curdled milk with the smell of stomach acid.” He said they couldn’t figure out why the suit smelled so bad or why the odor was so strong.

The curator mentioned that the suit had been used in both North Dakota and in the California almond orchards. He did some Internet research and discovered that some flowers produce bad-smelling honey, so he wondered if the foul smell could come from aster honey.

A good beekeeping mystery

First, I eliminated the aster honey: it can smell bad but not like that. Whenever I smell that sour, vomit-y smell, I’m reminded of lactic acid bacteria. If we assume the odor on the suit was not from an obvious cause—that is, the beekeeper didn’t get sick on it—I think the odor could have resulted from lactic acid bacteria living among the fibers.

Lactic acid bacteria are common organisms that decompose sugars in anaerobic (low oxygen) environments. They often cause spoilage in foods, including wine, and the scent of lactic acid bacteria is often described as “sour milk, cheesy, or rancid.”

Honey bees are loaded with lactic acid bacteria

We know that lactic acid bacteria live in the honey bee gut. In fact, researchers at Lund University in Sweden have found 13 different species living in the honey stomach of healthy bees. These bacteria metabolize sugars such as glucose, fructose, and maltose, all of which are found in nectar and honey.

Now we can assume that some of the gut bacteria are excreted in honey bee feces. And we can also assume that bee feces frequently adorns a beekeeper’s clothing, along with drips of honey and nectar.

If the suit was well-used and then stored in a low-oxygen environment such as the bottom of a plastic bucket or a toolbox in the back of a pickup, a large number of these bacteria could thrive on the bits of bee feces and the splatters of honey. Let the suit incubate in that warm, low-oxygen, food-rich environment for a few weeks and I’m sure you could nurture something that smelled really gross.

A second guess: butyric acid

I was pretty content with this theory until I remembered that some beekeepers use butyric acid to remove bees from honey supers. Butyric acid is a component of human vomit and the source of its characteristic odor. The smell is strangling and offensive, and it could very possibly be the real culprit here. The thing that confuses me is the description of “baby spit-up,” which to me is much milder than butyric acid, which is downright disgusting.

Of course, it’s impossible to establish the cause without seeing or smelling the suit in person, something I’m happy to miss. So I guess our smelly suit will remain an unpleasant mystery.

In any case, I wonder: Do people really donate filthy beekeeping suits to museums? Without washing them first? Wonders never cease.

Honey Bee Suite

Why does the bee suit smell like vomit?

Did the bees cause the odor or the beekeeper? Pixabay photo.


  • Rusty,

    Just throwing out ideas, here…

    It’s not uncommon for even pleasant scents to turn nasty if you combine several of them. Another thing I learned from making candles.

    I’m not sure if ti’s a chemical interaction or a type of sensory overload. But I’ve noted it several times. And, to me at least, ant objectionable odor, mixed with any sweet odor will make particularly noxious combination.

  • I would think frequent suit washing would prevent buildup of alarm pheromone?? Aside from the fact I like a clean, nice smelling suit! But I have never read that nor heard it mentioned in the bee literature…

  • Butyric acid is my instant thought. Maybe you just can’t remove it completely? This leads me to wonder if butyric acid is used to chase bees out of chimneys…and if the odor would remain indefinitely!!

    • Judy,

      That’s a scary thought. I never use butyric acid, so that’s why it didn’t occur to me right away. I don’t know if the odor will come out of clothing with a simple washing or not.

  • I’d love you to share your best washing secrets. Normal washing doesn’t do much for the propolis and feces and I hesitate to use bleach.

  • Hi,

    I have had good success using everclear on propolis, it should work on feces as well. I’ve had to use it to remove propolis from my dryer screen after my honey put my bee suit into the dryer after washing.

    Everclear is 151 proof grain alcohol. I tried lower proof grain alcohols, but they didn’t even lighten the color of the propolis. Everclear worked well and fast.

    As for the smell, I think sodium hydrogencarbonate (baking sode) may work, if they can get a concentrated solution to soak the suit in

      • Denatured alcohol sold in the paint section of any hardware store is cheaper than buying non-denatured ethanol (e.g. Everclear) with the associated federal and state alcohol taxes. I use it to get propolis off my hands and for doing alcohol wash mite sampling.

        • Cal,

          I use Everclear for removing propolis from my skin because it’s not denatured. I hate putting poison on myself.

  • Thanks Rusty, I wasn’t aware it came in higher proof! I had to go to North Carolina just to get the everclear I already have, as Virginia has limits on proof.

    I’ll have to remember to check other states if and when we get a chance to travel next year.

    • That acid is used by some beekeepers on a fume board to drive bees down out of supers in order to get the honey.

      NEVER thought of using it because of the smell. ?

  • Last summer (Australia) I had 2 hives within 2 weeks of each other begin to produce a bad odour, such as you described above associated with Lactic Acid Bacteria. It was intermittently very potent & I would get a whiff of it when walking past the hives. I was doing weekly inspections because of the odour & being very concerned that it could be AFB, the only described source of such foul odours coming from hives, in all my research. I was very confused as this is something which was described as being present in the latter stages of the colony being infected. Frame by frame I searched for some indication of EFB, AFB, SHB damage. Nothing they were all healthy hives with good stores of pollen & honey & strong healthy brood pattern. The strange thing was that other than an a slight breath of of bad odour when I initially took the lid off, I could not locate a single source for the odour within the hives. It seemed to dissipate once the hive was open.

    This lasted for about 2 weeks on & off, I asked experienced beekeepers, I sent photos, no one could explain, or see any issue with the frames or the bees. The only other option I was offered was rancid pollen, but I couldn’t see anything wrong with the pollen stored ( I took macro photos so I could better look at it close up) & again it didn’t smell bad, & I practically inhaled it & the odd larvae, as I became increasingly frustrated.
    However both of these hives did develop Chalk Brood, which began to be visually evident just after the foul smell stopped. I did find another beekeeper with the same problem, her colonies also developed Chalk Brood. After reading the above post I’m wondering if there could be some connection?

    • Kirsten,

      I don’t know of a relationship between bad odor and chalkbrood, but maybe someone here does. The bad odors I’ve noticed in summer have come when the workers were throwing out the drones in preparation for fall. Dead drones would land in the grass around the hives, and in the heat of the day, give off the most horrible smell. At first I though of AFB, but the smell is only outside the hives, not inside.

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