Four millets: More grains & the “millet spectrum”

The word “millet” in English is an inexact term. It can refer to any one of a number of cereals that have roundish grains, of which the four most cultivated worldwide – pearl/bajri, foxtail/xiaomi, proso, and finger/ragi – have been highlighted in the previous posts in this series. It can also refer collectively to all or some selection of them, perhaps including one or more other related grains that aren’t usually thought of as millets – notably sorghum, teff, and fonio. For instance, one overview of millets in Africa discussed pearl millet, finger millet, teff, and fonio. The below diagram of Indian millets, on the other hand, features bajra/pearl millet, ragi/finger millet, thinai/foxtail millet (recall the Chinese name associated with this is xiaomi), and sorghum, along with two others: varagu (kodo millet) and jowar (evidently a variety of sorghum).

Other millets and related grains

The grains of millets and related cereals range in size, with sorghum being the largest, pearl/bajri the next, and then a number of “small millets.” ICRISAT states that there are about a dozen “small millets,” including finger/ragi, foxtail/xiaomi, and proso, which we have already covered, but not including teff or fonio. A list of millets by FAO includes the latter two. A selection of the millets other than the four already profiled, drawn from ICRISAT’s and FAO’s lists as well as other sources, and ordered roughly by size of grain from large to small, are:

Sorghum (Sorghum bicolor) is sometimes also counted as a (large-grained) millet in Africa (where it originated) and the Indian subcontinent. It is a major crop worldwide – fifth overall (after corn/maize, rice, wheat, and barley, and before pearl millet) – grown for its grain and also for animal forage. See profiles in Lost Crops of Africa and the ICRISAT site. It is one of those grains touted as a possible “superfood.”

Kodo millet (Paspalum scrobiculatum), also called rice grass, originated in Africa but is cultivated mainly in India, as well as some countries in Southeast Asia. It apparently has been introduced to the US. Kodo is both wild and cultivated, and more suited to humid/damp habitats. See profiles on the USDA and IUCN Redlist sites.

Barnyard millet, may refer either to: Japanese barnyard millet (Echinochloa esculenta), or simply Japanese millet, which is grown primarily in Northeast Asia, but also in parts of the US (see profile on the USDA site); or to Indian barnyard millet (Echinochloa frumentacea), or billion-dollar grass, which is grown primarily in South Asia and parts of North America (see profile on the USDA site). These two, an uncultivated species, Echinochloa crus-galli, and perhaps others are closely related.

Little millet (Panicum sumatrense) is similar to proso millet but smaller. It is a minor crop in parts of Asia, in some areas grown up to 2100 meters altitude. See profile on the Useful Tropical Plants site.

Teff (Eragrostis tef) is a small grain of the Horn of Africa. It is described in Lost Crops of Africa, and featured last year on the BBC site as yet another superfood candidate. Teff is especially important in Ethiopian cuisine, used to make injera (እንጀራ).

Fonio, grown in various parts of West Africa, is actually two species. They are profiled in Lost Crops of Africa. The term fonio usually refers to Digitaria exilis, also known as white fonio, acha, or hungry rice. A 2014 article in The Guardian described its use in the US. Black fonio (Digitaria iburua) is grown primarily in Nigeria.

Millet spectrum

To make sense of this it might help first to consider these grains together as a “millet spectrum” ranging from large grains (sorghum) to very small (fonio). Yet this spectrum could also be reordered by color (which itself varies considerably within species) or regrouped by:

  • taxonomy (the website of the Millet Project in California has a simple breakdown by “tribe” within the grass family; note that ragi/finger millet is more closely related to teff than other grains we call millet)
  • tolerance to drought (bajri being perhaps the best in this category) vs. wet conditions (from the descriptions, kodo may be on the other extreme; sorghum, although adapted to drier conditions, can also support some inundation),
  • optimal latitudes of cultivation (per the tentative distinction made in the first post of this series between tropical or Afro-Indian millets, and temperate or Eurasian millets)
  • optimal altitudes of cultivation (ragi, teff, and little millet, for example, being adapted to higher altitudes),
  • grain structure (sorghum, pearl/bajri, and finger/ragi being more like wheat, and proso, foxtail/xiaomi, fonio, and kodo millet being more like rice in that they have hulls)
  • nutrient content (varies slightly, as one would expect, but there are some outliers, such as ragi’s calcium content)
  • flavor (a millet is not a millet when it comes to taste, even if the differences may in some cases be subtle)

To add to this complexity, each of these species has varieties and cultivars with different characteristics and names (for instance the US Alternative Field Crops Manual page on millets lists and compares several varieties of proso and foxtail). One expression of these differences in many millets, for example, is the color of the grains.

So it is a multifaceted group, which gets back to the original point of this series – to make a practice of distinguishing among the individual plants and, and from a consumer’s point of view, the individual grains. And in so doing, to also call attention to current labeling practices and regulation. But how to distinguish among millets when labeling doesn’t help?

Vive les différences!

Most millets you are likely to encounter are one of the main four discussed in this series of blogposts. Understanding which one you are looking at requires context and familiarity. Context begins with where you are, since different millets tend to be more common in different countries and cultures. In the US, most sold for human consumption is proso, though labels for it, foxtail/xiaomi and pearl/bajri will all indicate the same ingredient: “millet” (the exception seems to be ragi, which in my limited sample is labeled as “finger millet”). In different countries (and markets in the US carrying foods from them), the selection and likelihood of encountering another millet are higher, and the local names used may help disambiguate. Beyond that, characteristics like color or grain size may also help.

For example, when I found packaged millet flour at the Indian Spices store in Falls Church, Virginia, it was only the Indian name “bajri” that confirmed my hunch based on the color of the flour, that this was indeed pearl millet (the otherwise helpful staff did not know, so I did a websearch via smartphone).

As for familiarity, such as knowing the color of pearl millet flour or the relative size of proso and foxtail millets, I can only pass on some observations that give some idea. The following picture, for example, shows the grayish pearl/bajri flour on the left, and the reddish finger/ragi on the right.

Flour of pearl/bajri (l.) & finger/ragi (r.)

Varieties of foxtail/xiaomi and proso that I have seen have yellow grains. I have not seen flour of either, though I imagine it would be difficult to distinguish the two, even as neither could be mistaken for either of the above. However, there is a significant difference in grain size, as illustrated in the following picture.

Foxtail/xiaomi (l.), proso (r.)
Foxtail/xiaomi (l.), proso (r.)

A quick and very subjective characterization of taste: pearl/bajri, flat; finger/ragi, sharp; proso, round; and foxtail/xiaomi, faint. I find bajri and ragi to have stronger flavors, while xiaomi and proso are blander.


Variety hidden by a name

The purpose of this series of six posts on millets, in which the main four – bajri/pearl, ragi/finger, xiaomi/foxtail, and proso – have been highlighted, is to call attention to the differences among what often get lumped together as a single “millet.” These cereals are not the same, either in the field or on the plate, even if some subsets of the larger group are similar in one or another respect. Their very diversity represents, collectively, a resource for our future as we face both increased demand for food production and a changing climate.

To facilitate thinking about – and marketing of? – these main four millets as separate grains, I’ve suggested borrowing into English some common foreign terms which, like teff or fonio, do not use the word “millet.” A further step would be food labeling that tells consumers more about the identity of the product than just “millet.”


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