Cider apple
In the United Kingdom, the Long Ashton Research Station categorised cider apples in 1903 into four main types according to the proportion of tannins and malic acid in the fruit.
Barker, the first director of the Long Ashton Research Station (LARS) in Bristol, England,[2] established an analytical classification system for cider apples based on tannin and malic acid percentages in pressed juice.
[11] British cidermakers normally blend juice from apples of multiple categories to ensure a finished cider with a balanced flavour and for the best and most consistent quality.
[13] As bittersharps are rare, a common modern approach is to use a range of bittersweet varieties with some sharps, or a cooking apple such as the readily available Bramley, to balance the acidity.
[15] In France and Spain, the system has an intermediate category called acidulée or acidulada respectively, which is sometimes used to classify cider apples that are semi-tart and have low tannin content.
There are not a lot of cultivars with high tannins readily available in the U.S.[17] Most ciders in the United States are made from culled dessert apples that are generally sweets and sharps.
Other measurements taken of apple varieties towards use in cider classification include pH, polyphenol composition, yeast assimilable nitrogen (YAN),[8] and soluble solid concentration (ºBrix).
Most cultivars must reach pH levels of around 3.3 to 3.8 to aid in the fermentation process, and additions of malic acid may be necessary if the cider apple is over this desired threshold.
Soluble solids as measured in units of degrees Brix can be used to quantify the potential alcohol that a yeast can ferment from the initial juice of the cider apple.
This is carefully considered in cultivars from areas where there are tax regulations on the percentage of alcohol by volume that is contained in these products.
In the United States, "hard cider" legally falls between the 0.5% to 8.5% alcohol by volume tax bracket.
The other style, using specific cider apple cultivars with higher tannin levels, is usually associated with the West Country, particularly Somerset, and Three Counties.
The ciders of Devon were often made largely from sweets, the cultivars low in acid and tannins that typified the county's orchards.
[37] The large (7.6 meter) spherical-shaped canopies of traditional methods differ from various planting systems that use conic, flat planar or v-shaped styles.
[38] Traditional orchards have been found to produce apples with lower nitrogen content and higher polyphenolic levels.
[43] The decline is partly attributed to the high maintenance demands of large trees and the physical limitations for apple pickers,[42] the low yield (10-12 tons per hectare,[38]) the slow cropping of trees (15 years compared to the average 8 years of high-density orchards,[38]) and historical changes in regional alcohol preferences.
[38] In response to the rising demand for cider apples in the United Kingdom in the 1950s, the Long Ashton Research Station developed the bush orchard system commonly used in the UK today.
[46] High density planting became popular in the 1960s and 1970s, and is a common method of growing cider apples outside of the United Kingdom.
This allows growers to bring new varieties of apple to market more quickly than they could with traditional, more widely spaced orchard designs that are slower to mature.
[49] High density orchards are more labor efficient than traditional orchards, as workers do not need to climb ladders during maintenance or harvest[48] Pesticide application is also more efficient, as chemicals can be applied by over-the-row sprayers, fixed in-canopy systems,[50] or other devices that reduce pesticide waste.
Central leader trees grown with standard or semi dwarf rootstocks are large and free standing, unlike modern high density plantings.
[51] The central leader system has been adjusted in recent years to suit the requirements of modern orchard designs and high density plantings.
A less vigorous rootstock is used to limit growth, creating a smaller tree, usually individually staked for support of heavy cropping.
