Caryopsis

Each kernel of corn is a specialized type of fruit, called a caryopsis. So are rice, oats, barley, and wheat.

Unfamiliar fruits
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Fruits are the seed-bearing structure of angiosperms (flowering plants), made from the ovary (pericarp) of a fertilized gamete. Fruits taste good because that makes them more likely to be eaten, spreading seeds far and wide. We are all familiar with fruits. Apples, peaches, olives, and avocados are all fruits, but so are cereal grains.

Oats and wheat

Cereal fruits

Unlike apricots and nectarines, which have thick, juicy fruit walls, cereal grains have a very thin, dry fruit wall, or husk. A caryopsis is a simple fruit. This means they develop from a single pistil. Because there is no seam to split open and release the seed within, it is called indehiscent. Botanically, the outer skin of corn kernels and grain seeds is the pericarp, or husk. The husk is firmly attached to the seed coat. That is why special milling processes must be used to get at those edible seeds.

Ransomes, Sims & Jefferies Ltd. advertising poster, The Museum of English Rural Life, The University of Reading, UK Public Domain

​​Hulls, husks, and seed coats

Hulls and husks are the same thing - most of the time. Looking at an ear of corn, the leafy outer coating is called a husk. Botanically, a husk, or hull, is another name for a seed coat. It can also refer to a pea or bean pod. These outer coats are removed using a process called threshing. Threshing is a brutal process (if you’re a grain). Mules and other livestock have been used to walk in circles on the grain, breaking it free of its hard outer coat.

In some regions, grain is spread on roads to be threshed by cars and trucks. Traditionally, the dried fruit husk was removed using a flail.

After the grain was threshed, it had to be winnowed. Winnowing uses wind to separate the grain from the dried fruit hull, or chaff.

​Maybe, if we had to do all that work for our grains, too many carbs wouldn't be such a problem....

Once the dried fruit covering is removed, the remaining seed is called a groat. If that groat is parboiled, it is then called bulgur.

​Now you know.

Le vanneur (The Winnower) by Jean-François Millet Public Domain