Flax (also known as common flax or linseed) (binomial name: Linum usitatissimum) is a member of the genus Linum in the family Linaceae. It is native to the region extending from the eastern Mediterranean to India and was probably first domesticated in the Fertile Crescent. Flax was extensively cultivated in ancient Egypt. (New Zealand flax is not related to flax, but was named after it as both plants are used to produce fibres.)
Flax is an erect annual plant growing to 1.2 m tall, with slender stems. The leaves are glaucous green, slender lanceolate, 20–40 mm long and 3 mm broad. The flowers are pure pale blue, 15–25 mm diameter, with five petals; they can also be bright red. The fruit is a round, dry capsule 5–9 mm diameter, containing several glossy brown seeds shaped like an apple pip, 4–7 mm long.
In addition to referring to the plant itself, "flax" may refer to the unspun fibres of the flax plant.
Flax seeds come in two basic varieties, brown and yellow or golden, with most types having similar nutritional values and equal amounts of short-chain omega-3 fatty acids. The exception is a type of yellow flax called Linola or solin, which has a completely different oil profile and is very low in omega-3. Although brown flax can be consumed as readily as yellow, and has been for thousands of years, it is better known as an ingredient in paints, fiber and cattle feed. Flax seeds produce a vegetable oil known as flaxseed or linseed oil; it is one of the oldest commercial oils and solvent-processed flax seed oil has been used for centuries as a drying oil in painting and varnishing.
One hundred grams of ground flax seed supplies about 450 kilo-calories, 41 grams of fat, 28 grams of fiber, and 20 grams of protein.
One tablespoon of ground flax seeds and three tablespoons of water may serve as a replacement for one egg in baking by binding the other ingredients together. Ground flax seeds can also be mixed in with oatmeal, yogurt, wafer (similar to Metamucil), or any other food item where a nutty flavour is appropriate. Flax seed sprouts are edible, with a slightly spicy flavour. Excessive consumption of flax seeds can cause diarrhea.
Flax seeds are chemically stable while whole, and milled flaxseed can be stored at least 4 months at room temperature with minimal or no changes in taste, smell, or chemical markers of rancidity. Ground flaxseed can go rancid at room temperature in as little as one week. Refrigeration and storage in sealed containers will keep ground flax from becoming rancid for even longer.
Flax fiber is extracted from the bast or skin of the stem of flax plant. Flax fiber is soft, lustrous and flexible. It is stronger than cotton fiber but less elastic. The best grades are used for linen fabrics such as damasks, lace and sheeting. Coarser grades are used for the manufacturing of twine and rope. Flax fiber is also a raw material for the high-quality paper industry for the use of printed banknotes and rolling paper for cigarettes. Flax mills for spinning flaxen yarn were invented by John Kendrew and Thomas Porthouse of Darlington in 1787.
The major fiber flax-producing countries are Canada, USA and China, though there is also significant production in India and throughout Europe. In the United States, three states, North Dakota, South Dakota, and Minnesota, raise nearly 100% of this plant.
The soils most suitable for flax, besides the alluvial kind, are deep friable loams, and containing a large proportion of organic matter. Heavy clays are unsuitable, as are soils of a gravelly or dry sandy nature. Farming flax requires few fertilizers or pesticides. Within six weeks of sowing, the plant will reach 10-15 cm in height, and will grow several centimeters per day under its optimal growth conditions, reaching 70-80 cm within fifteen days.
Flax is harvested for fiber production after approximately 100 days, a month after the plant flowers and two weeks after the seed capsules form. The base of the plant will begin to turn yellow; if the plant is still green the seed will not be useful, and the fiber will be underdeveloped. The fiber degrades once the plant is brown. The mature plant is pulled up with the roots (not cut), so as to maximize the fiber length. After this the flax is allowed to dry, the seeds are removed, and is then retted. Dependent upon climatic conditions, characteristics of the sown flax and fields, the flax remains in the ground between 2 weeks and 2 months for retting. As a result of alternating rain and the sun, an enzymatic action degrades the pectins which bind fibers to the straw. The farmers turn over the straw during retting to evenly rett the stalks. When the straw is retted and sufficiently dry, it is rolled up. It will then be stored by farmers before scutching to extract fibers.
Flax grown for seed is allowed to mature until the seed capsules are yellow and just starting to split; it is then harvested by combine harvester and dried to extract the seed.
Threshing is the process of removing the seeds from the rest of the plant.
The process is divided into two parts: the first part is intended for the farmer, or flax-grower, to bring the flax into a fit state for general or common purposes. This is performed by three machines: one for threshing out the seed, one for breaking and separating the straw (stem) from the fibre, and one for further separating the broken straw and matter from the fibre. In some cases the farmers thrash out the seed in their own mill and therefore, in such cases, the first machine will be unnecessary.
The second part of the process is intended for the manufacturer to bring the flax into a state for the very finest purposes, such as lace, cambric, damask, and very fine linen. This second part is performed by the refining machine only.
The threshing process would be conducted as follows:
Before the flax fibers can be spun into linen, they must be separated from the rest of the stalk. The first step in this process is called "retting". Retting is the process of rotting away the inner stalk, leaving the outer fibres intact. At this point there is still straw, or coarse fibers, remaining. To remove these the flax is "broken", the straw is broken up into small, short bits, while the actual fiber is left unharmed, then "scutched", where the straw is scraped away from the fiber, and then pulled through "hackles", which act like combs and comb the straw out of the fiber.
Pond retting is the fastest. It consists of placing the flax in a pool of water which will not evaporate. It generally takes place in a shallow pool which will warm up dramatically in the sun; the process may take from only a couple days to a couple weeks. Pond retted flax is traditionally considered lower quality, possibly because the product can become dirty, and easily over-retts, damaging the fiber. This form of retting also produces quite an odor.
Stream retting is similar to pool retting, but the flax is submerged in bundles in a stream or river. This generally takes longer than pond retting, normally by two or three weeks, but the end product is less likely to be dirty, does not stink as much, and because the water is cooler it is less likely to be over-retted.
Both Pond and Stream retting were traditionally used less because they pollute the waters used for that process.
Field retting is laying the flax out in a large field, and allowing dew to collect on it. This process normally takes a month or more, but is generally considered to provide the highest quality flax fibers, and produces the least pollution.
Retting can also be done in a plastic trash can or any type of water tight container of wood, concrete, earthenware or plastic. Metal containers will not work, as an acid is produced when retting, and it would corrode the metal. If the water temperature is kept at 80 °F, the retting process under these conditions takes 4 or 5 days. If the water is any colder it takes longer. Scum will collect at the top and an odour is given off like in pond retting.Now enzymatic retting of flax is widely employed.
The dressing is done as follows: