Propolis, often called “bee glue,” is a resinous substance honeybees create by mixing collected plant resins with their own wax and salivary enzymes. This sticky compound serves as the hive’s natural sealant, used to fill small gaps, sterilize the interior, and defend against pests and pathogens. Harvesting this material involves specific methods to maximize yield while maintaining the colony’s health.
Preparing the Hive and Gathering Supplies
Before opening the hive, gather all necessary equipment, including a standard hive tool for scraping and a dedicated, non-porous container for collecting the raw material. Propolis is exceptionally sticky and will permanently stain clothing and tools, so designate a specific set of scraping implements for this task. Protective gear, such as a veil and gloves, is necessary, along with a smoker to calm the bees.
Timing the harvest correctly can significantly improve the yield and quality. Bees naturally increase propolis production in late summer and early fall as they prepare to seal the hive against winter drafts. While collection is possible throughout the active season, this period of increased sealing activity offers the greatest abundance.
The ambient temperature influences the physical state of the propolis, affecting the ease of collection. When temperatures are warmer, the material is soft, pliable, and sticky, making it difficult to scrape cleanly. Conversely, when it is cold, propolis becomes brittle and shatters easily, which may result in small, fragmented pieces. Always ensure the colony is strong and healthy before harvesting, as taking too much propolis can compromise the hive’s natural defenses.
Practical Methods for Collecting Propolis
Beekeepers use two primary methods to collect propolis, balancing product purity with collection simplicity. The traditional method involves scraping the material directly from hive components during routine inspections. Using a stiff, metal hive tool, one can carefully peel or scrape deposits found on the inner cover, frame top bars, and the joints between hive bodies.
Scraping is a low-yield process that often results in a raw product mixed with debris like wood splinters, paint chips, and beeswax. To minimize contamination, focus scraping on the thickest, cleanest deposits, typically found where bees have sealed larger gaps. The collected material should be deposited immediately into a dedicated, air-tight container to prevent sticking.
For a higher and cleaner yield, beekeepers rely on specialized propolis traps, which are flexible plastic or mesh screens designed with small openings. The trap is placed directly on top of the uppermost box, beneath the inner cover, creating a drafty, uneven space the bees are compelled to seal. The small mesh holes encourage the bees to fill them with propolis rather than bridging them with beeswax comb.
To encourage faster work, some beekeepers slightly prop open the outer cover, allowing light to filter down onto the trap. The bees respond to this light and perceived draft by rapidly filling the screen openings with propolis over a few weeks. Once the majority of the holes are filled, the trap is removed, typically yielding 50 to 100 grams of propolis per harvest.
Collection from the trap exploits the temperature-dependent consistency of propolis. The entire filled trap is sealed in a plastic bag and placed into a freezer until the propolis is completely frozen and brittle. Once frozen, the screen is immediately flexed, bent, or struck against a solid surface. This action causes the hardened propolis to cleanly crack and flake off the flexible plastic mesh, falling directly into the collection bag.
Sustainable harvesting dictates that beekeepers leave sufficient propolis for the bees’ own use, particularly as winter approaches. Limit the number of times a propolis trap is used in a season on any single colony to avoid stressing the bees. The hive must always have enough natural sealant left to maintain its internal environment and structural integrity.
Cleaning, Curing, and Storing the Harvest
Raw propolis collected through scraping is almost always contaminated with wax, wood, and other hive debris, requiring cleaning to isolate the pure resin. The most straightforward purification method is cold water separation, which takes advantage of propolis’s high density. The raw material is first frozen and broken into small pieces, then submerged in cold water.
Pure propolis is heavy and sinks to the bottom, while lighter impurities like beeswax and wood fragments float to the surface. The floating debris is carefully skimmed off the water’s surface, and the process is repeated until no more contaminants rise. After the water is poured off, the clean, wet propolis is collected from the bottom.
Another cleaning technique involves gentle heating, which is effective for removing excess wax. Propolis is placed in water and heated to approximately 200 degrees Fahrenheit, a temperature sufficient to melt the beeswax without damaging the propolis compounds. The melted wax floats to the top, forming a solid layer once the water cools, which is then easily removed from the underlying purified propolis mass.
Once cleaned, propolis must be allowed to thoroughly cure or dry before long-term storage to prevent mold or sticking. The material should be spread in a thin layer on parchment paper in a cool, dark location away from direct sunlight until all residual moisture has evaporated. If the propolis was soft and sticky during collection, this curing process helps it maintain its form.
For long-term preservation, propolis should be stored in an airtight container, such as a glass jar, in a cool, dark environment. Freezing is the optimal storage method, as the low temperature preserves the potency of the propolis compounds indefinitely. Many beekeepers immediately process cleaned propolis into a tincture by dissolving it in high-proof grain alcohol, which serves as a common and effective method of preservation.