Sorghum

Sorghum bicolor

Tannins, starch · the tallest of the grain crops

Sorghum grows taller than anything else in a Korean grain plot. Sow it in rows in May or June and cut it in September or October, once the heads bend over. It shrugs off drought and poor ground, which is why it often goes along the edge of a plot or in a row as a windbreak. The Donguibogam lists it in the Grain section as 秫薥, describing it as the tallest of the grains with large, plentiful kernels, planted in the north as a famine reserve and otherwise fed to cattle and horses, and known in the south as 蘆穄. The bran layer is astringent, so hulled sorghum is rinsed several times and soaked before cooking.

Year-Round Calendar

Sowing

Harvest

Where It Grows

Main producer Major producer Latitudes at 25–32℃ Zoom and pan to explore · temperatures are rough zonal averages

Main producer Production centers on the southern Great Plains, in Kansas and Texas, and most of the crop goes to livestock feed and industrial use. Harvest September, October
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10. 10
Main producer It is the staple grain of the northern savanna. Cutting comes around the time the rains stop. Harvest October, November, December
10. 10
11. 11
12. 12
Major producer This falls within northeastern Africa, counted as the region where the crop was domesticated, and it is still widely grown here as a staple grain.
Major producer Known as jowar, it centers on Maharashtra and Karnataka. Rainy-season plantings and winter plantings are made separately, so there are two harvest seasons. Harvest October, November, February, March
2. 2
3. 3
10. 10
11. 11
Major producer Called durra, it is the staple of the Nile valley and of the drier savanna. Harvest November, December
11. 11
12. 12
Major producer It is grown on a large scale in Tamaulipas and Sinaloa for livestock feed.

It was domesticated in northeastern Africa, in what is now Sudan and Ethiopia, and cannot be pinned to a single country, so no country-of-origin row has been given. After establishing itself as a staple across the semi-arid belt south of the Sahara it crossed into Asia, and in the twentieth century it expanded sharply as livestock feed on the US Great Plains and in Mexico. The same crop is therefore a food grain for people in Africa and a feed and industrial raw material in the Americas.

Optimum: 25~32℃
Range: 15~40℃
Hardiness: Not hardy
Day length: Short-day

A tropical-origin field crop that stands up to heat and drought. It is short-day — the heads form only as the days shorten — so moving a traditional landrace to a different latitude throws the heading time out of step. Below 15℃ growth stops, and frost kills the plant.

In Korea Nationwide

A minor grain long planted in rows along the edges of dry fields and on paddy banks, with no notable production area. Waxy sorghum is the main type planted.

How to grow

Light: Six hours of direct sun or more. In shade the heads come in small
Soil and depth: Any free-draining field soil will do. It tolerates poor ground but not a spot where water sits
Spacing: 15 to 20cm between plants, 60 to 70cm between rows. Sow in rows and thin at three or four true leaves
Watering: Drought-hardy. Even so, do not let it dry out in July and August while the heads are forming
Feeding: Base dressing is enough, and go easy on nitrogen. Too much and the plants run to height and go over
Harvest: Cut the heads in September or October, once the grain resists a thumbnail and the head bends over. Hang them in airy shade to dry, then strip the grain

What makes the difference. Many types pass 2m. Run a line on the windward side, or earth up the base to firm the crown, and far fewer plants go down

Why this one is harder. Sparrows find the heads the moment they colour. Bag the heads or net the plot as soon as colour shows. A few days' delay leaves the heads empty

Common problems

Asian corn borer You will see Holes in the stem with sawdust-like frass around them; stems snap What to do Find the caterpillar below the hole and remove it, and clear every stubble stem from the plot after harvest
Aphids You will see Colonies on the head stalk and leaf undersides, leaves turning sticky What to do Wash off with a jet of water; if it recurs, use an egg-yolk oil spray or an approved organic product
Head smut You will see Grains in the head replaced by a mass of black powder What to do Bag the affected head before the spores scatter and pull the plant. Avoid the same ground next year and start from clean seed

This page describes how a crop is grown and used. It does not claim health effects for any food, nor is it intended to prevent or treat disease. Component and study notes are references only and do not mean the same result occurs in people. Consult a medical professional about health concerns.

Health Benefits

What the Donguibogam records — the names 秫薥 and 蘆穄. The Donguibogam lists sorghum in the Grain section as 秫薥. It calls it the tallest of the grains, with kernels that are large and plentiful, planted in the northern provinces as a famine reserve and otherwise fed to cattle and horses. It also records that southerners call it 蘆穄. The passage carries no note on the grain's nature or taste. This is a historical medical record and differs from modern medical judgment.

Tannin types and compositional analysis. Proanthocyanidin-type polyphenols are identified in sorghum, and the level is reported to follow not the colour of the outer coat but the presence of a pigmented testa, the mark of the tannin sorghums. Analyses also report that content falls sharply with the degree of milling and the number of soaking rinses. This concerns compositional analysis and has no bearing on preventing or treating disease.

Storage protein family. Sorghum's main storage protein is kafirin, which compositional analysis places in a different family from the proteins that form wheat gluten. Studies also report that heating cross-links kafirin and slows enzyme action on it. This is a record about cereal protein composition.

Nutrition

Starch (carbohydrate) (about 73g per 100g, hulled grain) — the amylopectin share separates waxy from non-waxy types
Proanthocyanidins (tannins) (marked in tannin sorghums, the types that carry a pigmented testa) — the polyphenols behind the astringency
Protein (kafirin) (about 9 to 11g per 100g) — a storage protein from a different family than wheat gluten

Starch composition and stickiness The texture of cooked sorghum follows the ratio of amylose to amylopectin in its starch. Types that are almost all amylopectin are the waxy sorghums; those with a measurable amylose share are the non-waxy ones. Whether a pounded cake stretches or crumbles comes down to that. Two types grown side by side cross-pollinate and blur, so keep them apart or stagger the sowing dates.

Tannins and the testa The astringency of sorghum comes from condensed tannins, the proanthocyanidins. Whether a type carries them turns not on the colour of the outer coat (the pericarp) but on whether it has a pigmented testa, a subcoat that forms only in lines holding both the B1 and B2 genes — the tannin sorghums. A red or brown pericarp with no testa behind it shows almost none, so colour alone is no guide to how astringent a grain will be. Even in tannin types, analyses report that milling off the outer layer and soaking with repeated rinses removes a good share of them. Throw the rinse water away and cook in fresh water.

Protein and digestibility Most of sorghum's protein is kafirin, a storage protein. Heating makes kafirin cross-link, which analyses report slows the access of digestive enzymes. That is the background to the long soaking and thorough cooking sorghum has always had. Eaten with beans or adzuki, the amino acid profiles cover each other.

Pairings

○ Adzuki beans and glutinous rice — Sorghum cakes with red bean, and sorghum pancakes, are the long-standing use for waxy sorghum. Waxy sorghum alone does not bind well, so glutinous rice flour goes in with it. The adzuki adds the lysine sorghum is short of.

○ Rice and mixed grains — Hulled sorghum is harder than rice and needs a head start. Soak it at least two hours, rinse, then add it to the pot. Begin at 10 to 15 percent of the rice, judge the astringency, and go up from there.

○ Beans and pulses — Like other cereals, sorghum is low in lysine, and pulses are high in it. Cooked together, the two profiles fill each other in. Their soaking times are close enough to share one bowl of water.

△ Young plants and regrowth after cutting — Young sorghum leaves and stems, and especially the regrowth that follows a cut, contain dhurrin, a cyanogenic glycoside. Livestock poisoning from grazing sorghum at this stage is well documented. The only part people eat is the mature grain; the leaves and stems are never used as a green. Thinnings from the plot go on the compost heap, not in the pot.

△ Unrinsed bran — Under-milled sorghum cooked straight from the bag stays sharply astringent. Rinse until the water runs clear, soak, and discard the soaking water. If you are grinding it whole, start with a smaller proportion.

△ Mouldy heads — Heads left out in a long wet spell after ripening mould easily. Discard any grain that has changed colour or smells musty. Mycotoxins do not wash off and do not boil away. Once cut, hang the heads somewhere airy and dry them fast.

Varieties

Waxy sorghum (chalsusu) (seed) — Starch almost entirely amylopectin, so it cooks sticky. Used for sorghum pancakes and red-bean cakes
Non-waxy sorghum (mesusu) (seed) — Not sticky. Mixed into rice or milled to flour
Broomcorn (jangmok-susu) (seed) — Long, spreading head branches. This is the sorghum once tied into brooms
Sweet sorghum (dansusu) (seed) — Sugary stems that were chewed by the joint. Grain yield is low

Source: Donguibogam, Grain Section 秫薥 · Rural Development Administration (Nongsaro) · Korean Food Composition Table