The question of whether bees are attracted to apple cider vinegar (ACV) is common. ACV is produced through a two-step fermentation process that converts apple sugars into alcohol, and then into acetic acid, resulting in a liquid known for its sharp taste and pungent aroma. This substance presents a unique sensory challenge to bees, whose survival depends on accurately identifying floral sources for nectar and pollen. Determining the bee’s reaction requires understanding how they perceive the world.
The Sensory World of Bees
Honeybees possess a sophisticated system of chemoreception that allows them to “taste” and “smell” their environment to locate food and avoid harmful substances. Their primary sensory organs for detecting odors are the two antennae, which are covered in thousands of specialized sensory hairs called sensilla. These sensilla are highly tuned to volatile organic compounds, enabling the bee to navigate a complex landscape of floral scents over long distances.
The sense of taste, or gustation, is a more direct assessment, carried out by gustatory receptors located on the antennae, mouthparts (proboscis), and the tarsi, or forelegs. A bee landing on a potential food source can instantly “taste” it using these receptors on its feet, which is a rapid mechanism for evaluating a liquid’s quality. Bees are known to perceive the four basic tastes: sweet, salty, sour, and bitter, although their sensitivity thresholds differ significantly from humans.
Compared to other insects, honeybees have a significantly smaller number of gustatory receptors, reflecting their specialized diet of nectar and pollen. This limited taste repertoire means they are highly focused on detecting sugars but less equipped to sense a wide variety of plant toxins. The bee’s response to any liquid is a rapid integration of its olfactory signal (smell) with the immediate gustatory feedback from the tarsi.
Chemical Composition and Bee Preference
Commercial apple cider vinegar is typically standardized to contain approximately 5% acetic acid, which is the compound responsible for its characteristic sourness and low pH. The acidity level of undiluted ACV is quite low, often registering around pH 2.4, a level far more acidic than the average nectar source. This high concentration of acetic acid creates a volatile, pungent odor that serves as a strong signal to the bee’s olfactory system.
In its undiluted state, the intense acidity and strong odor of apple cider vinegar generally act as a deterrent, prompting bees to reject it as a potential food or water source. Bees naturally prefer sugar solutions within a specific concentration range, typically between 30% and 50% sucrose, and they will actively avoid highly acidic or bitter liquids. The acetic acid component of ACV, when present at its full strength, overrides any residual sweetness from the initial apple fermentation.
The bee’s reaction shifts dramatically, however, when ACV is diluted and mixed with a sugar solution. Honey itself is naturally acidic, with a pH ranging between 3.9 and 4.5, which is lower than the neutral pH of plain sugar syrup used by beekeepers. When ACV is added to sugar syrup at a very low concentration, it lowers the solution’s pH to mimic the natural acidity of honey. This diluted, slightly acidic mixture is not repellent and may even be preferred by bees over neutral syrup, as it more closely aligns with their natural diet.
Practical Applications in Beekeeping
Beekeepers intentionally utilize the chemical properties of apple cider vinegar, not as a primary attractant, but as a beneficial feed additive for honeybee colonies. When mixed into sugar syrup, the acetic acid helps to invert the sugar molecules, breaking down complex sucrose into the simpler sugars, fructose and glucose. This process is thought to make the syrup easier for bees to digest and metabolize, especially during periods of high consumption like winter feeding.
The acidification of sugar syrup also creates an environment that inhibits the growth of unwanted microorganisms, such as certain bacteria and molds, that can spoil the feed. Furthermore, research has demonstrated that an acidic environment can have a direct effect on certain honeybee viruses. The low pH can prematurely inactivate viruses such as Sacbrood virus, Deformed Wing Virus, and Slow Bee Paralysis Virus by causing the viral structure to open, thereby preventing infection.
Beyond its role as a feed supplement, concentrated acetic acid is also employed by beekeepers as a chemical fumigant to sterilize hive components. High-concentration acetic acid (60% to 80%) is used to treat empty hive equipment and combs to kill the spores of Nosema, a common gut parasite, and to control wax moth infestations. This application involves sealing the equipment, allowing the acid fumes to permeate the material, and is used solely for sterilizing equipment, not treating living bees.