Bilberries are picked in clean growing environments in sparsely populated areas away from population centres and where there is no polluting industry.
95% of Finnish forests are unfertilised, which means that some of the bilberry harvest is certified as organic, with more available to correspond to demand. Approximately 10% of the annual bilberry harvest is picked. The season lasts just a few weeks and a large number of berries grow in forests far from roads. Picking is quite hard work, since the berries are picked using handheld berry picking tools and without using any machinery. It is not permitted to damage the forest’s ground cover or drive a motor vehicle in the forest.
Berry picking tools
The best time to pick bilberries is from mid-July in southern Finland until early September in northern Finland. The berry can be picked in autumn right up until the temperatures fall below zero at night. The berries are picked when they are ripe. Clean buckets or boxes suitable for foodstuffs are used to pick and transport the berries. Hygienic working methods are used when handling the berries. The berry picker is the first step in a long quality chain for berry products.
During the picking phase, the bilberries must be completely ripe and dark blue throughout. The bilberry is ready for picking around two weeks after it turns blue. Ripe berries contain more healthy polyphenols than unripe berries. They are also larger and come away from the shrub more easily than unripe berries. The bilberries retain their quality better if they are picked during dry weather. It is best to protect picked berries from the sun, since warmth and light reduce the berries’ vitamin content.
Wild bilberries are picked using a handheld berry picking tool. Industrial pickers use a so-called berry picking rake with a long handle, which prevents backache since the picker does not have to bend over so often. Various berry picking tools are sold in Finnish stores and markets. Picking tools make the berry picking process quicker. Berry pickers should remember not to handle the picking tool too roughly to avoid damaging the shrubs. Bilberries are emptied from the picking tool into buckets or containers in which the berries are transported for sale.
Industry purchases bilberries from first purchasers
Each year, 4–7 million kilograms of bilberries are purchased for industry from first purchasers. Berry pickers who pick berries for sale do not need to clean the berries, and loose leaves from the shrub may be included with the crop. Pickers transport the berries themselves to first purchase points. The first purchaser usually purchases the berries uncleaned. In this way, the berry keeps better before handling. Lorries transport the bilberries from first purchase points to industrial facilities for freezing. The bilberries are frozen in tunnels on the day they are picked at temperatures of -40 degrees Celsius.
Bilberries that are frozen after the harvest season are cleaned using industrial cleaning equipment. Debris is removed using an air blower. The machinery also removes the stem and optical food sorter removes discoloured berries. Individually quick frozen (IQF) Arctic bilberries are sold by the berry industry to industries which produce berry products, to professional catering enterprises and to households in small packages via food stores. In industry, the quality of berries and resulting berry products is strictly monitored. This ensures that the berries’ nutritional values and quality are preserved better than is the case with slow-freezing at home.
Drying is another processing method in addition to freezing. Bilberries are primarily air-dried in a warm air current with a maximum temperature of approximately +45 °C. Dehydration prevents enzyme and microbial activity in the berries. The bilberry is sufficiently dry when its residual moisture content is approximately 10–12%. One kilogram of fresh berries produces approximately 100 grams of dried bilberries.
It is also possible to use the more expensive freeze-drying process when manufacturing specialty products. Freeze-drying involves the dehydration of berries using a vacuum at extremely low temperatures (approx. -50 °C), whereupon the water transitions directly from a solid to a gas state. The shape, appearance and nutritional content of the products are preserved extremely well.