Barley

A hardy grain with many faces

Barley, Hordeum vulgare, is a cereal grass in the same tribe as wheat and rye, and every cultivated form belongs to the one species. Its grain is long and slightly twisted, and most of its weight is endosperm, the starchy store, at about 77 per cent. The husk takes about 13 per cent, the pericarp and testa 3.3 per cent, the aleurone layer 5.5 per cent and the germ 3 per cent. Barley is sorted by how many rows of grain the head carries, two or six; by whether the husk stays glued to the kernel (covered) or falls free on threshing (naked or hulless); and by whether it is sown in spring or winter. Brewers prefer two-row types, and six-row types are mostly fed to livestock.

The names follow it across the Caucasus and Asia: keri (ქერი) in Georgian, gari in Armenian, arpa in Azeri, and qingke in Chinese or nas in Tibetan for the hulless six-row barley that feeds the Tibetan Plateau. Barley is not wheat. Its storage proteins are hordeins rather than the gliadins and glutenins of wheat, so a barley dough forms far less of a stretchy gluten network, and barley flour is usually blended with wheat flour for bread.

Where barley comes from

Barley is one of the oldest crops. Its wild ancestor, Hordeum vulgare ssp. spontaneum, was first described from Turkey by the German botanist Carl Koch, and the first definite sign of cultivation in the arc of the Middle East is more than 10,000 years old. Domestication left traces in the grain. Wild barley shatters, scattering its seed; cultivated barley holds its grain on a tough stalk so that it can be harvested, and spikes of this kind turn up at Tell Abu Hureyra about 9,500 years ago. Naked kernels, which thresh free of the husk, appear at Ali Kosh about 8,000 years ago. The most striking change was the six-row head, which carries three times as many seeds as the two-row head it came from, and the gene behind it suggests that this change was made more than once. The first domesticated barleys were probably winter types; spring barley, sown in spring, came later through a mutation that arose many times.

From the Middle East barley followed farmers into Europe, Africa and Asia. In Tibet the hulless six-row type became the principal cereal at least 3,500 years ago, and genetic evidence shows it arrived in the southern plateau between 4,500 and 3,500 years ago from the eastern part of barley’s range, not from a local domestication. In the Southern Caucasus barley has been cultivated for thousands of years because it tolerates cold winters and poor conditions. In Georgia it is among the oldest cultivated crops: mountain communities grew it for forage, bread and beer, used it in traditional rituals and folk medicine, and kept many varieties. Breeders’ varieties now dominate, and only a few landraces survive on very small areas in the high mountains of Khevsureti and Tusheti. The area under barley in the decade before the national report was between 75,000 and 100,000 hectares.

From staple to malt

Barley was probably first a human food, and it has remained the most important food source of some cultures, especially in Asia and North Africa. As wheat displaced it from the bread of richer regions, barley found new work as the feed grain of livestock and as the raw material of malt. Ancient Arabic, Chinese, Egyptian, Ethiopian and Greek writers praised it for strength and stamina and used it in medicine. Much of the world’s barley grows where maize and rice do not thrive. It is among the best-adapted cereals, grown in climates from subarctic to subtropical.

The modern trade reflects those choices. World production was about 147 million tonnes in 2021/22 after about 160 million the year before, with the European Union the leading producer at 52.75 million tonnes. Only about 6 per cent of the crop becomes human food, mostly in soups and some flour. The rest is split between animal feed and the malting and brewing industry, which wants a two-row barley with a modest protein level and a plump, uniform kernel.

What is in the grain

Starch is the main component. Whole-grain barley contains about 58 to 61 per cent starch, 12 to 15 per cent protein, 2.5 to 2.7 per cent fat, and 17 to 21 per cent dietary fiber, of which beta-glucan is 4.8 to 5.7 per cent, depending on whether the barley is covered or naked. Naked barley has more protein, fat and soluble fiber than covered. Barley starch normally holds amylopectin and amylose in a ratio of about three to one, though waxy types are 95 to 100 per cent amylopectin and some cultivars have 40 to 70 per cent amylose.

Beta-glucan, a gummy fiber in the cell walls of the endosperm, is barley’s distinguishing nutrient. It dissolves into a viscous solution that slows the absorption of glucose, and the U.S. Food and Drug Administration and the European Food Safety Authority have approved health claims linking barley beta-glucan to lower blood cholesterol. The same fiber causes trouble in the brewery, where it thickens the wort. Protein runs from about 7 to 25 per cent across more than 10,000 genotypes tested and sits at 9 to 13 per cent in typical barley; high-protein barley suits food and feed, while low-protein barley suits malting.

Forms and how to cook them

Covered barley must lose its husk before it can be eaten. Dehulled grain with the bran layer largely intact is chewy and slow to cook. Pearling grinds off more of the husk, bran and germ in stages: the first stage gives pot barley, with most of its bran, and further polishing gives white pearled barley, the most common form, which cooks faster, with fewer nutrients, and is used as a substitute for rice and in soup. Naked barley needs no dehulling, and its bran layer stays on unless it is pearled. Flakes are barley steamed and rolled like oats; grits are cut, roasted or steamed pieces; flour is made by roller-milling pearled barley; and roasted covered barley makes the tea called mugi-cha in Japan.

Malted barley is a separate product: sprouted grain dried in a kiln. Ground into malt flour it comes in two kinds: diastatic, with active enzymes, which is added to flours that have little natural diastatic activity, and non-diastatic, which has none and is used for its flavor, in malted milk and for a softer crumb and glossier surface in baked goods.

Barley in bread and the kitchen

Barley bread is not one worldwide formula. Barley flour behaves differently from wheat flour because it does not make the elastic, extensible gluten network that supports a tall, open loaf. Bakers use it as a share of a wheat dough, shape it into flat breads that need less expansion, or dry baked loaves a second time. These are different choices, not interchangeable recipes. Flat-bread research distinguishes batter from firm dough, leavened from unleavened dough, and griddle or hearth baking from oven baking; some forms depend on gluten while others use non-wheat flours.

Iranian jow is a place-specific barley bread named in a review of traditional flat breads: jow is Persian for barley, and the review describes this leavened, single-layered flatbread as made from barley flour. It sits alongside, rather than representing, Iran’s better-known wheat breads. The same review explains why flat breads accommodate diverse grains: a thin sheet or batter can be cooked quickly on a griddle or other hot surface, while a high, elastic loaf depends more heavily on its flour’s dough structure.

In Orkney, the Rowett Institute gives a beremeal bannock formula using 115 g beremeal or barley flour with 115 g plain white flour, baking powder, salt, vegetable oil spread and milk. The wheat flour shares the dough; baking powder raises it chemically, so this recipe is not a fermentation. The source shapes the mixture into two thick rounds and cooks them on a griddle or in an oven. It describes bannocks as a broader Scottish, Irish and northern English family, with Orkney’s beremeal version as one regional member.

Lapin ohrarieska offers a different balance: the published Finnish Lapland batch uses barley flour alone with cold water, salt and baking powder. The instructions keep the dough cold, mix it only until it holds together, press two rounds by hand and bake them on a preheated sheet for 5–8 minutes at the hottest practical oven setting. The author gives soft and crisp cooling options. This is a documented modern formulation for Lapland rieska, not a general formula for every bread called rieska.

Cretan rusks show barley in a mixed-grain bread that is baked twice. A regional booklet describes cutting bread into slices and baking it again to dry, and associates dakos with Crete. One current Cretan producer lists wholegrain barley flour, wheat flours, barley sourdough, barley malt, yeast and salt in its Ntakos-style barley rusks. That ingredient list is a producer’s formula, not a universal rusk recipe. The dry rusk is served with salads; the second bake is a drying stage, distinct from the sourdough and yeast activity in the dough.

Taken together, these cases show barley as an entire flour in one flatbread, a half-share in a chemically raised bannock, and a major grain in mixed sourdough rusks. Their differing structures and stages explain why a single barley-to-wheat ratio cannot be prescribed for all baking. Home preparation is supported where a source gives a specific batch and method; the quantities and conditions belong to that version only. Barley contains gluten-related proteins and is not suitable for people who must avoid gluten.

How malt works in fermentation

Malting is germination under control, not fermentation. The grain is steeped in water at 14 to 16 °C until it holds 42 to 48 per cent moisture, which wakes the embryo, and it is allowed to germinate. In the sprouting grain enzymes dismantle the cell walls and part of the protein of the endosperm, which is called modification, and build up the starch-splitting enzymes that will be needed later. Kilning then dries the green malt to 4 to 6 per cent moisture, which fixes the enzymes and develops color and flavor. Over- or under-modified malt gives too much or too little protein and dextrin in the beer, and kilning can also start lipid oxidation, which makes the stale cardboard flavor of trans-2-nonenal.

The malt’s enzymes do their work in the mash. Milled malt is stirred into water and heated for hours, and alpha-amylase chops the long starch chains into smaller pieces for beta-amylase, which snips off maltose, a sugar yeast can ferment. Together with limit dextrinase and alpha-glucosidase these enzymes make up what brewers call diastatic power. The husks form a filter bed through which the sweet liquid, the wort, drains; about 60 to 70 per cent of the dry matter goes into the wort and the rest remains as spent grain. A good malt yields at least 80 per cent extract on a dry basis. The amino acids released from the protein, measured as free amino nitrogen, feed the yeast that ferments the wort, and beta-glucan left undegraded makes wort slow to run and can haze the beer. Wort is a prepared substrate; yeast turns it into beer only afterward.

How koji works on barley

The second large role of barley is as a bed for koji. Koji is the mold Aspergillus oryzae grown on steamed or boiled grain; on barley it is called barley koji, and on rice, rice koji. As the mold grows it secretes amylases, which break starch down to sugars, and proteases, which break protein down to amino acids and peptides, and these enzymes do the work in the later miso or sauce. Koji is a mold culture that supplies enzymes; the later fermentation of the miso is a separate stage.

Japan’s agriculture ministry sorts miso by the grain of its koji. Barley miso, also called country-style or inaka miso, is made with barley koji, salt and steamed soybeans, and its production is limited to Kyushu, Shikoku and Chugoku and part of Kanto. Its table lists two barley types, amakuchi, with a koji-to-soybean ratio of 15 to 25 and salt of 9 to 11, and karakuchi, with a ratio of 8 to 15 and salt of 11 to 13; barley miso is light-colored or red. Without temperature control it needs at least 8 months, spanning one summer, or about six months held at 27 °C, and it tastes best after about a year and a half to two years. It is eaten across Japan and is most popular in Kyushu.

Choosing it, storing it and who cannot eat it

Choose barley by the job. Pearled barley suits soups and rice-style dishes; hulled or hulless barley keeps more bran and chew; malt is bought as a brewing grain or as a malt flour, and the diastatic or non-diastatic label says whether it carries working enzymes. Keep dry grains in airtight containers that exclude moisture, dust and insects. Follow the date on the package for dry barley, and keep cooked barley as you would any cooked grain.

Barley contains gluten. The protein is hordein, and the National Institute of Diabetes and Digestive and Kidney Diseases names barley with wheat and rye as the grains whose gluten triggers celiac disease, which is treated with a strict gluten-free diet. Foods made from the grain, such as malt, should be assumed to contain it unless the label says otherwise.