Birch sap,birch water or birch juice is the sap directly tapped from birch trees, Betula pubescens (white birch), Betula pendula (silver birch), Betula lenta , Betula papyrifera , and Betula fontinalis .
Birch sap may be consumed both fresh and naturally fermented. When fresh, it is a clear and colourless liquid, often slightly sweet with a slightly silky texture. After two to three days, the sap starts fermenting and the taste becomes more acidic.
Birch sap is a traditional beverage in boreal and hemiboreal regions of the Northern Hemisphere [1] as well as parts of northern China.
Birch sap is collected only at the break of winter and spring when the sap moves intensively.
Birch sap collection is done by drilling a hole into the tree trunk and leading the sap into a container via some conduit (a tube or simply a thin twig); the sap will flow along it because of the surface tension. The wound is then plugged to minimise infection. [2]
Birch sap has to be collected in early spring before any green leaves have appeared, as in late spring it becomes bitter. The collection period is only about a month per year.
No published evidence exists to quantify the long-term impacts of sap harvest on birch tree and birch forest health, or birch timber quality. [2] However, the wounds caused by tapping birches consistently lead to dark staining in the wood. [2] In one study, infection and wood decay had spread from more than half of old tapping holes. [2]
In comparison to maples, birch trees are considered far less tolerant to the wounds caused by tapping, so more conservative harvesting practises have been recommended by trade bodies such as the Alaska Birch Syrupmakers Association. [2]
Ancient Balts, Slavs and Finns regarded birch as one of their most sacred trees [3] [4] and made a traditional beverage from it.
In Slavic regions the sap is known as birch juice as in Russia (Russian : берёзовый сок, romanized: byeryozovyi sok), Belarus (Belarusian : бярозавы сок, romanized: biarozavy sok, Byarozavik), Bulgaria (Bulgarian: брезов сок, romanized: brezov sok), Poland (Polish : sok z brzozy, oskoła), Slovakia (Slovak : brezová šťava), Ukraine (Ukrainian : березовий сік, romanized: berezovyi sik).
Estonia (Estonian : kasemahl), Finland (Finnish : mahla), Latvia (Latvian : bērzu sula), Lithuania (Lithuanian : beržo sula, beržų sula), Norway, [5] Sweden (Swedish : björksav). [6]
France, Scotland and elsewhere in Northern Europe [1] as well as parts of northern China and both Hokkaido and Aomori as parts of northern Japan.
It is also widely used among the Pennsylvania Dutch, both as a traditional beverage in its own right, and particularly as a key ingredient in birch beer. [7]
Nutritional value per 100 g (3.5 oz) | |||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Energy | 4.6 kcal (19 kJ) | ||||||||||||||||||||
1.1 g | |||||||||||||||||||||
Sugars | 1.1 g | ||||||||||||||||||||
Dietary fiber | 0 g | ||||||||||||||||||||
less than 0.1 g | |||||||||||||||||||||
| |||||||||||||||||||||
†Percentages estimated using US recommendations for adults, [9] except for potassium, which is estimated based on expert recommendation from the National Academies. [10] |
Birch sap contains heterosides (betuloside and monotropitoside), [11] 17 amino acids including glutamic acid, [12] as well as minerals, enzymes, proteins, betulinic acid and betulin, [13] [14] [15] antioxidants, [16] sugar (fructose, glucose and small amounts of sucrose) and vitamins (C and B(group)). [16] Contrary to popular belief, there is no xylitol in birch sap (xylitol is a sugar alcohol that is industrially produced using high temperature and sulfuric acid, or through fermentation). [17]
Folk uses have been documented which include medicinal use, supplementary nutrition, and cosmetic applications for skin and hair. [1]
Region | Traditional medicinal use | Cosmetic use |
---|---|---|
Belarus | lung diseases, gout, sickness | washing hair |
Bulgaria | hair growth | |
Czech Republic | poor health, infertility | against freckles |
Estonia | (prevention of) eye diseases, skin diseases, source of vitamins | washing hair, against freckles and to bleach the skin |
Hungary | stomach and lung diseases | against freckles |
Latvia | “revitalization” | washing hair |
Poland | “revitalization”, kidney stones | washing hair in order to strengthen it |
Romania | kidney stones, jaundice, as milk-rennet, scab, diuretic | hair colouring, to remove sunspots and moles |
Russia | externally against sores, to help children during teething | washing face |
Sweden | scurvy, cholera | |
Ukraine | treating skin diseases, source of vitamins, diuretic | against freckles |
United Kingdom | tonic, rheumatism, first nourishment for new-born children | prevention of baldness |
United States | Poor health |
Birch sap may be consumed both fresh and naturally fermented. Fresh birch sap is highly perishable; even if refrigerated, it is stable for only 7 days. Shelf life can be prolonged by freezing or preservation techniques. Existing preservation techniques include: [18]
Birch sap can also be used as an ingredient in food or drink recipes, [19] such as birch beer or wintergreen-flavored candy.
Concentrated birch sap is used to make birch syrup, a very expensive type of syrup mainly made from paper birch in Alaska [20] and Canada, and from several species in Latvia, Russia, Belarus, and Ukraine.
Maple syrup is a syrup made from the sap of maple trees. In cold climates, these trees store starch in their trunks and roots before winter; the starch is then converted to sugar that rises in the sap in late winter and early spring. Maple trees are tapped by drilling holes into their trunks and collecting the sap, which is processed by heating to evaporate much of the water, leaving the concentrated syrup.
Molasses is a viscous byproduct, principally obtained from the refining of sugarcane or sugar beet juice into sugar. Molasses varies in the amount of sugar, the method of extraction and age of the plant. Sugarcane molasses is usually used to sweeten and flavour foods. Molasses is a major constituent of fine commercial brown sugar.
A prune is a dried plum, most commonly from the European plum tree. Not all plum species or varieties can be dried into prunes. A prune is the firm-fleshed fruit (plum) of Prunus domestica varieties that have a high soluble solids content, and do not ferment during drying. Use of the term "prune" for fresh plums is obsolete except when applied to varieties of plum grown for drying.
A birch is a thin-leaved deciduous hardwood tree of the genus Betula, in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus Betula contains 30 to 60 known taxa of which 11 are on the IUCN 2011 Red List of Threatened Species. They are typically short-lived pioneer species and are widespread in the Northern Hemisphere, particularly in northern areas of temperate climates and in boreal climates. Birch wood is used for a wide range of purposes.
Palm wine, known by several local names, is an alcoholic beverage created from the sap of various species of palm trees such as the palmyra, date palms, and coconut palms. It is known by various names in different regions and is common in various parts of Africa, the Caribbean, South America, South Asia, Southeast Asia, and Micronesia.
Xylitol is a chemical compound with the formula C
5H
12O
5, or HO(CH2)(CHOH)3(CH2)OH; specifically, one particular stereoisomer with that structural formula. It is a colorless or white crystalline solid. It is classified as a polyalcohol and a sugar alcohol, specifically an alditol. Of the common sugar alcohols, only sorbitol is more soluble in water.
Buttermilk is a fermented dairy drink. Traditionally, it was the liquid left behind after churning butter out of cultured cream. As most modern butter in Western countries is not made with cultured cream but uncultured sweet cream, most modern buttermilk in Western countries is cultured separately. It is common in warm climates where unrefrigerated milk sours quickly.
Betula pubescens, commonly known as downy birch and also as moor birch, white birch, European white birch or hairy birch, is a species of deciduous tree, native and abundant throughout northern Europe and northern Asia, growing further north than any other broadleaf tree. It is closely related to, and often confused with, the silver birch, but grows in wetter places with heavier soils and poorer drainage; smaller trees can also be confused with the dwarf birch.
Sap is a fluid transported in xylem cells or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant.
Betula papyrifera is a short-lived species of birch native to northern North America. Paper birch is named after the tree's thin white bark, which often peels in paper-like layers from the trunk. Paper birch is often one of the first species to colonize a burned area within the northern latitudes, and is an important species for moose browsing. Primary commercial uses for paper birch wood are as boltwood and sawlogs, while secondary products include firewood and pulpwood. It is the provincial tree of Saskatchewan and the state tree of New Hampshire.
Betula alleghaniensis, the yellow birch, golden birch, or swamp birch, is a large tree and an important lumber species of birch native to northeastern North America. Its vernacular names refer to the golden color of the tree's bark. In the past its scientific name was Betula lutea, the yellow birch.
Birch syrup is syrup made from birch sap, and produced in much the same way as maple syrup. However, it is seldom used for pancake or waffle syrup as it has a much stronger flavor profile, more often it is used as an ingredient paired with pork or salmon dishes in sauces, glazes, and dressings, and as a flavoring in ice cream, beer, wine, and soft drinks.
Birch beer is a beverage, commonly found as a carbonated soft drink made from herbal extracts and birch bark. There are dozens of brands of birch beer available.
A spile is a wooden or metal peg used to control the flow of air into, and carbon dioxide out of, a cask of ale or wine. Spiles can also be used to broach liquids from a tree.
Agave syrup, also known as maguey syrup or agave nectar, is a sweetener commercially produced from several species of agave, including Agave tequilana and Agave salmiana. Blue-agave syrup contains 56% fructose as a sugar providing sweetening properties.
Neera, also called palm nectar, is a sap extracted from the inflorescence of various species of toddy palms and used as a drink. Neera extraction is generally performed before sunrise. It is sweet, translucent in colour. It is susceptible to natural fermentation at ambient temperature within a few hours of extraction, and is also known as palm wine. Once fermented, Neera becomes toddy. Neera is widely consumed in India, Sri Lanka, Africa, Malaysia, Indonesia, Thailand, and Myanmar. Neera is not the juice made from palm fruit.
Palm syrup is an edible sweet syrup produced from the sap of a number of palms. It is produced in the Canary Islands and coastal regions of South America.
Byarozavik is a Belarusian traditional drink made from birch sap. Makers harvest the sap from birch trees once a year, from March to April. Tree damage from sap collection to make this drink led to a licensing system for the collection of sap, introduced in 2008.