How to harvest Propolis?
Propolis consists of resins collected by bees from trees and shrubs, as well as wax, which is a secretion from the bee’s body. Raw propolis also usually contains a certain amount of solid impurities. The valuable element in propolis from a medicinal properties point of view is the resins. They are soluble in ethanol, which makes it possible to easily separate them from the wax and impurities through ethanol extraction.
Harvesting propolis can be done traditionally by scraping or by using grids (collectors, traps).
The traditional method involves scraping the propolis off the frames, bars, and other parts where bees usually deposit it. Propolis obtained by this method may contain various kinds of impurities. Besides wax, this also includes pieces of wood, parts of dead bees. Such propolis usually needs to be cleaned (by sorting or rinsing) so that it ultimately contains no more than 50% wax and other impurities (substances insoluble in ethanol). The goods supplied by beekeepers generally contain 30-50% solid impurities. This is entirely normal and according to the Polish Standard corresponds to the second quality class of propolis.
Harvesting propolis using grids takes advantage of the fact that bees try to seal gaps up to 3.5 mm wide with propolis. The method involves placing a special mesh or grid in the hive, called a collector, trap, or grid. These grids are usually made of durable, flexible, low-temperature-resistant plastic and have small holes that bees try to seal with propolis. The grids with propolis should be collected regularly, usually once a week, during other apiary activities. After removing the grids from the hive, they are placed in a freezer. After taking them out of the freezer, the propolis is easy to crumble off. Then, the propolis should be dried to prevent it from becoming moldy. It is worth noting that the use of traps allows for the intensification of propolis production, but on the other hand, forcing bees to kit intensively can lead to an increased wax content in the propolis.
Propolis should not contain:
– mold (visible under a magnifying glass),
– wax moth or other pests at any stage of development,
– impurities such as asphalt or tar,
– residues of antibiotics or other chemical or pharmacological substances.
The amount of propolis that can be collected depends on factors such as the breed of the bee, the type of vegetation in the area, and weather conditions. In our climate conditions, one can usually expect about 100g of propolis per hive annually.