Nuts obtained from Galician native forests of European chestnut (Castanea sativa, Mill.) intended for human consumption and sold either fresh or frozen. The forests consist of the series of local eco-types that have been obtained from selections made over centuries by farmers seeking to improve production and quality.
Sweet tasting and a firm, non-floury texture.
Their main distinguishing features are:
- smooth, brown and shiny outer skin
- fine membrane slightly penetrating the seed and easily separated when peeled
- the nut has between 50 and 60% moisture content when harvested
- generally speaking, each spiny husk contains 3 or fewer nuts
- average percentage carbohydrate content of 59.5% (of dry weight)
- very low percentages of cracked (4.5%) and separated (2.1%) kernels
Properties that the fruit must have after harvesting:
- minimum moisture content of 50% and maximum of 60%
- maximum percentage of separated kernels: 12%
- minimum percentage of carbohydrate content: 55%
- maximum number of nuts per kg (2.2 lb) must not be more than 120 if the product is fresh and 200 if frozen.
Production / Processing method
The traditional method of growing chestnuts in Galicia is in soutos (plantations of trees of the same or similar ages that are all treated in the same way). However, the protected chestnuts can also be grown in new controlled plantations. The main aspects of looking after edible chestnut trees are concerned with pruning, grafting, working the soil, fertilizing, irrigating and harvesting.
The two kinds of pruning methods used on the trees are spur and goblet pruning. For goblet pruning, all the branches growing out of the lower two thirds of the trunk are cut; in spur pruning, branches are not cut but left to grow freely. When setting up new plantations or when rejuvenating existing ones, the trees should be grafted with varieties that will produce good quality chestnuts and that come from the various Galician native chestnut stocks.
In plantations where the landscape and conditions permit, once or twice a year, very superficial (only 4-8 cm / 1.5-3.1 ins) digging over and weeding is done, so as not to damage the chestnuts upper roots, taking care to leave a space of about 1 meter (3.2 ft) around the tree. In plantations where digging over the soil is not advised, any weeds or plants whose size and invasive nature are potential threats to the tree are removed. In addition to fertilizers applied at the time of planting, it is advisable to use top-up fertilizer every year to safeguard production and improve harvest quality. The climate and soil conditions in the production area mean that the trees do not normally need extra water, except during the initial period after planting.
Harvesting normally starts in late September or early October and lasts about a month, depending on the chestnut varieties and on where the plantation is located. The protected chestnuts fall naturally from the tree and are collected carefully to safeguard their quality. They are placed in situ in properly labeled recipients that ensure they are well aired.
Transport to the warehouse or processing plant is done in special vehicles and they must not be mixed with other non-protected products. The chestnuts that are not taken to fresh storage facilities or processing plants must be stored in producers' own premises or in those of the operator-seller, under the correct conditions.
In the plant, the chestnuts undergo reception treatment, followed by cleaning, pre-calibrating and selection processes. Depending on the various forms of presentation, other processes the chestnuts pass through include the following:
Fresh: disinfection, following legally permitted methods, brushing, calibrating, selection, preparation and packaging.
Frozen: before being frozen, the chestnuts are peeled, either using fire or steam, and then washed. Freezing is done by direct contact with liquid nitrogen or dry ice, or by applying jets of air. Once the freezing process is completed, the product is packaged and stored in special freezer rooms.
Geography / Relief and climate
The production area has a very wet climate, with yearly accumulated rainfall of around 1,000 mm, but summers are usually fairly dry until September. These weather conditions are very favorable for obtaining good quality chestnuts. This area excludes Galicia's coastal regions, where the recommended figures for growing chestnuts are exceeded. Average annual temperatures are 6-14ºC (42-46ºF) which is within the recommended range for chestnuts (3-16ºC / 37-60ºF), with high summer temperatures that are very good for ripening and developing the nuts. The eastern half of Galicia is where weather conditions and temperatures are the best for chestnuts. The defined area coincides with altitudes to which chestnuts are best adapted (in the range of 400-900 m, but not exceeding 1,200 m).
Most of the land has soils normally found on granite and metamorphic rock (schists and slate) with a loamy texture, rich in organic matter, with low pH and low active lime content, regarded as the best for growing chestnuts.
Consejo Regulador de la IGP Castaña de Galicia
Rúa Progreso, 28
Tel: (+34) 649 061 915
- Spanish Ministry of Agriculture
- Instituto Galego da Calidade Alimentaria (INGACAL)
Each spiny husk contains three or fewer nuts.