Blackcurrant is a species of Ribes berry native to central and northern Europe and northern Asia, and is a perennial.
It is a small shrub, growing to 1–2 m tall. The leaves are alternate, simple, 3–5 cm long and broad, and palmately lobed with five lobes, with a serrated margin. The flowers are 4–6 mm diameter, with five reddish-green to brownish petals; they are produced in racemes 5–10 cm long.
When not in fruit, the plant looks similar to the redcurrant shrub, distinguished by a strong fragrance from leaves and stems. The fruit is an edible berry 1 cm diameter, very dark purple in colour, almost black, with a glossy skin and a persistent calyx at the apex, and containing several seeds dense in nutrients. An established bush can produce up to 5 kilograms of berries during summer.
Plants from Asia are sometimes distinguished as a separate variety, Ribes nigrum var. sibiricum, or even as a distinct species Ribes cyathiforme.
There are many cultivars of blackcurrant, including: Amos Black, Ben Alder, Ben Avon, Ben Connan, Ben Dorain, Ben Gairn, Ben Hope, Ben Lomond, Ben Loyal, Ben More, Ben Sarek, Ben Tirran, Big Ben, Boskoop Giant, Cotswold Cross and Wellington XXX.
New varieties are being developed continually to improve frost tolerance, disease resistance, machine harvesting, fruit quality, nutritional content and fruit flavour.
Varieties producing green fruit, less strongly flavoured and sweeter than typical blackcurrants, are cultivated in Finland, where they are called "greencurrants" (viherherukka).
During World War II, most fruits rich in vitamin C, such as oranges, became almost impossible to obtain in the United Kingdom. Since blackcurrant berries are a rich source of vitamin C and blackcurrant plants are suitable for growing in the UK climate, blackcurrant cultivation was encouraged by the British government. Soon, the yield of the nation's crop increased significantly. From 1942 on, almost the entire British blackcurrant crop was made into blackcurrant syrup (or cordial) and distributed to the nation's children free, giving rise to the lasting popularity of blackcurrant flavourings in Britain.
The fruit has extraordinarily high vitamin C content (302% of the Daily Value per 100 g), good levels of potassium, phosphorus, iron and vitamin B5, and a broad range of other essential nutrients .
Other phytochemicals in the fruit have been demonstrated in laboratory experiments with potential to inhibit inflammation mechanisms suspected to be at the origin of heart disease, cancer, microbial infections or neurological disorders like Alzheimer's disease. Major anthocyanins in blackcurrant pomace are delphinidin-3-O-glucoside, delphinidin-3-O-rutinoside, cyanidin-3-O-glucoside, and cyanidin-3-O-rutinoside which are retained in the juice concentrate among other yet unidentified polyphenols.
Blackcurrant seed oil is also rich in many nutrients, especially vitamin E and several unsaturated fatty acids including alpha-linolenic acid and gamma-linolenic acid. In a human pilot study, ingestion of blackcurrant seed oil by mothers reduced atopic dermatitis in their breast-fed newborns who were supplemented with the oil over two years.
In the UK, blackcurrant cordial is often mixed with cider to make a drink called "Diesel" or "Snakebite and Black" available at pubs. Adding a small amount of blackcurrant juice to Guinness is preferred by some to heighten the taste of the popular stout. Macerated blackcurrants are also the primary ingredient in the apéritif crème de cassis. Japan imports $3.6 million of New Zealand blackcurrants for uses as dietary supplements, snacks, functional food products and as quick-frozen (IQF) produce for culinary production as jams, jellies or preserves. In Russia, blackcurrant leaves may be used for flavouring tea or preserves. Sweetened vodka may also be infused with blackcurrant leaves or berries, making a deep yellowish-green beverage with a sharp flavour and astringent taste.
Besides being juiced and used in jellies, syrups, and cordials, blackcurrants are also used in cooking because their astringency creates flavour in many sauces, meat dishes, and desserts.
It was once thought that currants needed to be "topped and tailed" (the flower remnants and the stalks removed) before cooking. This is not the case, though, as these parts are easily assimilated during the cooking process. If one prefers, the whole blackcurrant stem and fruit can be frozen, then shaken vigorously. The tops and tails will break off, and the fruit can then be easily separated.
Ribena, a non-carbonated soft drink flavored with blackcurrants, takes its name from Ribes.
Blackcurrant berries have a distinctive sweet and sharp taste popular in jam, juice, ice cream, and liqueur (see Ribena). They are a common ingredient of Rødgrød, a popular kissel-like dessert in North German and Danish cuisines. In the UK, Europe and Commonwealth countries, some types of confectionery include a blackcurrant flavour, and in Belgium and the Netherlands, cassis is a flavoured currant soft drink. In the United States, blackcurrant flavour is rather rare in candies and jellies compared to UK sweets. In the United States, grape flavour is often used in brands of candy where blackcurrant would appear in Europe. Blackcurrant syrup mixed with white wine is called Kir or Kir Royale when mixed with Champagne.