PROPOLIS PRODUCTION IN THE APIARY
V. I. Lebedev
Translated from Pcelovodstvo magazine
Propolis is one of the most valuable beekeeping products. Health institutions from all over the world show special interest in propolis since it helps in cases of pulmonary tuberculosis, chemical and temperature burns, problematic ulcers and wounds, angina, tonsillitis, pharyngitis, bronchitis, pulmonary inflammation, digestive tract diseases. Scientists from USA found that pinocembrin, a unique antioxidant is contained in propolis up to 10% (A. Elizabeth Sloan, 2000).
It is determined that bees use only propolis to fill gaps from 0.1 to 3.5 mm, while those from 3.5 to 10 mm are filled with wax or wax mixed with propolis. They are much more active in filling smaller cracks (0.1 - 3 mm) than bigger (3 - 5 mm). Bees put more propolis above than in or bellow the nest. The depth of filling cracks grows proportionally from bellow upwards: bellow the nest 1 – 2 mm, in the nest 1 – 3mm, and above 1 – 4mm. Such behaviour is explained with the fact that the upper part of the hive is where the main temperature loss is happening, so bees fill the gaps there most thoroughly and fast. Generally, temperature loss is a great stimulus for bees to collect and store propolis.
The vast majority of propolis collecting devices in the world is based on bee’s instinct to fill gaps and openings in the hive smaller than 4mm. The amount of this product in the hive is variable and depends on many factors: bee breed, geographic and climate conditions, hive type, presence of propolis source in nature, strength of a bee colony. Gray mountain bees from Caucasus collect great amounts of propolis, dark forest bees collect a lot of it, Italian bees collect less, while bees from Ukraine and far east collect very little propolis. So, in the same conditions bees collect different amounts of this product and store it in different places in the hive. It is most often found in three places: on cover boards (or other types of covers) above the nest, on the frames’ sidebars in the nest, and in the hive entrances.
The amount of propolis collected from one hive also varies. Some sources from literature state that one can collect 50 – 100g, while others mention 150 – 200g. Some beekeepers think that one colony may produce 400g of propolis and that this amount can be increased to 2kg and more using special procedures.
Taking into account the causes which incite bees to collect propolis, it is possible to increase the amount of it with success. It is favourable to have increased ventilation in the hive, uneven surfaces of cover boards and hive walls, special types of hive entrance bars, and some sort of teasers for bees.
Propolis collecting framework with wooden or plastic bars is often used in practice (M. V. Krasnopeev, pat. 447138; A. P. Stan, pat. 548248). These bars make temporary gaps 3 – 4 mm wide, which make it possible to get 250 – 400g of pure propolis in one season. They are put over hive frames while cover boards and all isolating material are removed. In 6 – 7 days bees fill the gaps between bars with propolis, after which bars are replaced with new ones. Propolis is obtained from the bars which are completely removed or turned 45 degrees. Bars are put in a rough cloth, rolled in so that the bars are inside, and put in a deep freezer for several hours. After that, they are taken out and unrolled with bars down, so that propolis falls down on the table.
P. P. Lakers (1972. pat. 337107) recommended a mesh with bars on different heights which are linked with each other, which makes it possible to get 1kg of propolis. The mesh is also put over hive frames instead of cover board and isolating material.
Some beekeepers use cover boards with openings screened with a network. They put a piece of gauze coated cotton on them on which they apply 50 drops of mint and dill oil. Formic acid can also be used as a teaser. Bees are irritated by a sharp strange smell and they fill the openings of the network with pure propolis, which should be occasionally taken off with a hive tool. In addition, this makes varroa mites fall down.
Hungarian beekeepers obtain up to 2 kg of propolis in one hive by increasing hive ventilation and using ribbed and sloping cover boards. They put three plastic networks with differently sized openings on hive frames bellow isolating fabrics. They put 100x100mm network at the bottom, 3x3mm in the middle and 25x25mm on top.
An original system for gathering propolis was designed in Brazil, which made it possible to get 800g of the purest propolis from one colony. A “window” is made on a hive’s side wall and closed with bars. Bees maintain specific ventilation in their nest and according to the number of bars a beekeeper removes they fill the gaps (about 8mm) with propolis. Nowadays Brazil is the chief exporter of propolis to Japan where there is a constant growth in its demand.
Some beekeepers use special cassettes which they put on hive entrances instead of entrance boards. Thus they get a large opening which is closed with a cassette. In order to limit the level of nest ventilation and optimize microclimatic conditions, bees intensively put propolis on the cassette network. When filled with propolis the cassettes are taken out from the hive and kept on low temperature (-10…-20°C). The frozen propolis is easily removed from the network with light tapping.
Propolis is most easily collected using a plain hive tool for scratching it from hive walls, frame bars, isolating material, around hive entrances and different cracks. However, this method is not productive.
In order to increase propolis production 3-4 times and automate its gathering it would be best to use special two layer covers made of Capron network with 4x4mm openings. In spring they are put above the nest on the frame top bars bellow the isolating material. During hive inspection these covers are turned 90 degrees in the direction of the hive entrance. They are not left in the hive during winter to avoid their contamination with bee excrement and wax.
The propolized covers are taken out in autumn when bee colonies are preparing for winter. Propolis is removed mechanically or by extracting. In the first case covers are frozen and then modified on an electrical device SIP-II. A revolving shaft with cogs grinds the hardened propolis while a smooth shaft pushes the cover towards the working shaft using a string. In this process propolis is roughly and finely cleansed.
Using centrifugal extracting machine CLK-1 propolis pieces are grinded to powder and at the same time cleansed from impurities which cannot occupy more than 20% in propolis ready for use. In retail trade propolis powder is measured in amounts from 25 to 100g and pressed in briquettes using OKS-030 or P-6324 pressing machine with 25000kg force. Propolis powder is previously kept about 4 hours on room temperature.
Propolis should not be warmed, washed or melted since as a result it loses a part of its characteristics. It is kept in a dark place in polyethylene bags. Propolis is very stable matter, so it can safely be used 10 years from the day of obtaining.
Translated by Oliver Mihajlovic