Frost fans – Innovation by Midalidare in frost fighting
The land of Mogilovo village is a natural Eden for viticulture. The terroir is unique and one of the natural blessings is the great temperature amplitude. A blessing which provides the optimal content of acidity, and which represents a necessary condition for the unique style and exceptional ageing potential.
Unfortunately, once a year this blessing turns into a curse. In mid Spring the temperature amplitudes often become a perquisite for frosts of the vine shoots. Over the years we fought this natural phenomenon via thermal inversion by helicopter, but this method is quite expensive and not fully effective. The best techniques worldwide are wind machines. Frost fans are used for years in USA, New Zealand, Australia, France, Germany, Italy and many other countries for preventing the crops, not only vineyards, but also orchards. Our leased New Zealand vineyards are also equipped with these devices and after several years of planning we decided to make this investment also for our precious vineyards Shipkata, Karaliets and Prisovete. In Bulgaria there are some orchards protected by frost fans, but Midalidare is the first winery to implement this technology.
Frost fans are mechanical devices designed to mitigate the impact of frost on crops. The devices operate on the principle of air mixing – using the temperature inversion they redistribute warmer air from higher altitudes to the ground level. During the radiation frost event, heat from the soil is radiated into the atmosphere forming a warm laver called inversion level. Frost fans utilize this inversion layer and mix the warmer air with the colder, denser air found on ground level. This effectively lifts the ground temperature by a few degrees to minimize the risk of frost occurrence.
Upon making the decision about this huge investment we created a strategic map of our most endangered vineyards and purchased 14 frost fans. A single large frost fan typically protects 4 to 6 hectares and placing one or two on a 44-ha vineyard will just pass the cold air from one block to another. Of course, if the block is small and at the end of the vineyard, as is the endangered block on Prisovete vineyard, one device will be completely sufficient. So, we placed the remaining 9 frost fans on Shipkata vineyard and 4 frost fans on Karaliets vineyard with strategy each one to pass the cold air to the next one. Thus, when the frost enters the lowest block, the first device shoves it out to the neighboring one until the cold air is completely ventilated out of the vineyard. The process is completely automated, and the devices are synchronously preset.
Today, on April 28th, is the first “working day” of our investment. We believe this is the right way to protect our vines and thus ensure not only good crops but healthy plants and wonderful wines!
