Produits céréaliers en anglais
Davidson (Oxford Companion to Food)
Groats and grits are terms which come from the same root and are almost synonymous. The former is more used in Britain and usually refer to oats which habe been husked (hulled), and crushed rather than ground ; while the latter is used in N. America, especially the southern states, where hominy grits (see also maize) are important.
Groats are not necessarily of oats and grits need not be of corn (maize), but if other grains are meant, these have to be specified (as in barley groats). Grits used alone would normally be taken to mean hominy grits (and hominy used by itself would usually refer to a more coarsely ground product than grits).
Gruel is a variation fo porridge, made from finely ground oatmeal, which is mixed with water or milk, allowed to soak, and then cooked. Eventually the solids are strained out of the mixture ; there is some disagreement as to whether or not this should take place before or after cooking. The result is smooth, and jellies when cold.
The name gruel is derived from the French gruau, which means finely ground flour. Medieval gruels might contain vegetables, herbs, or meat, such as 'drawn gruel', which contained the juices drawn from cooked beef, or 'forced gruel', mixed with pounded pork. Other versions were sweet, containing dried fruit, sugar, and butter ; or medicinal, with herbs to purify the blood. The Scots regarded gruel as good for coughs and colds.
Semolina is usually made from the very hard durum wheat, a variety of Mediterranean origin which is now grown mostly in the USA and Canada. When coarsely milled, the brittle grains fracture into sharp chips, and it is these which constitute ordinary semolina.
... In fact, a finer semolina flour is available ; this is used for making pasta, so durum wheat is sometimes called macaroni wheat.