From Mill to Bowl

Most porridges are made with grains, as are tons of other basic foods that most people eat every day, like bread, pasta, noodles, or tortillas. But it can be pretty daunting to understand how different ingredients are produced, or where they come from, and even harder to decide what is delicious or healthy. For example, walking down a grocery aisle, you might pass by bags of rice, bags of flour, boxes of pasta, and tubes of oats. These are all grain products, but they look and behave in totally different ways.

It helps to understand what constitutes a grain, and what each of these parts mean in terms of food. A grain is a seed, and is composed of the germ, the endosperm, and the bran. The seed is often harvested in an inedible husk or hull. Once the inedible husk has been removed, the whole grain is known as a groat. The germ is the essentially the embryo of the new plant. The bran is a protective shell. The endosperm is a fuel source for the young plant until it can produce its own food. From a nutrition standpoint, the bran has a lot of fiber and protein, while the endosperm is mostly starch, and the germ contains fats and proteins. The germ and bran contain the majority of the vitamins and minerals of the grain. See Porridge In Your Body for a more detailed explanation of grain nutrition and how these parts relate to health. groat

Every part of a grain, whether whole or separate, can be turned into some form of porridge. When grain agriculture began in various places around the world, thousands of years ago, boiling whole grain in water was the easiest and most straightforward way to access the calories of the grain. As time progressed, certain cultures starting milling and processing grains. Milling grain into flour made bread possible. In other instances, grains were processed but not fully milled, in order to change the flavor or convenience of the grain.

These differences are straightforward. Whole grains are delicious, but take a long time to cook. Grinding or breaking the whole grain into smaller pieces makes it cook faster. Removing the bran and the germ speeds up the cooking time, and increases the shelf-life of grain (the germ contains fats, which eventually go rancid at room temperature). Removing the bran and germ also make for softer flours, which makes higher quality pastas and noodles. However, removal of the bran and germ takes away most of the nutritive value of the grain, and allows the body to digest it more quickly. Letting whole grains sprout or germinate alters the chemical makeup of the grain, releasing some key nutrients and making the grain generally more nutritious (although the extent to which sprouted grains are healthier is debated). Soaking the grain in liquids, such as lye, makes it softer and easier to grind, and changes the nutrient makeup. Fermenting grain breaks down various sugars and proteins, changing the flavor and making it easier to digest (some say).

There are lots of grain products that are mistakenly identified as grains, or simply aren’t explained at all. Ultimately, there is a logic behind all of the various milling processes of grain. Processing is not evil, nor is whole grain primitive. We do our best to embrace whole grains, but there are wonderful, delicious, and useful milled grains as well. Here is a brief explanation of the milling of some of the most common grains consumed in the U.S.


Rolled oats, quick oats, Irish oats, Scottish oats, steel-cut oats, oat groats… All very similar in nutrition, but different in flavor, texture, and convenience. All of these are milled whole grains – the bran and germ remain in the end product. The oat groat is the basic form. Steel-Cut or Irish oats are chopped oat groats. Rolled oats get steamed, then pressed by mechanical rollers. Quick oats are rolled oats that get chopped up even more. Scottish oats are effectively a coarse oat flour. Essentially, the smaller the pieces, the faster the oats cook, and the more consistent the texture. Oat bran is also common – it is higher in fiber and lower in carbohydrates than whole oats, but it is not “healthier” – it is just lacking the germ and endosperm.


There are many varieties of wheat, most of which can be found as groats (often called wheatberries) or as flour. Durum, spelt, emmer, einkorn, khorasan, and farro are some popular whole grain species. Semolina (used as a grain, and also to make certain pastas) is the endosperm of durum wheat. Bulgur and freekeh are wheat groats that have been partially cooked and cracked. White flour is milled endosperm, while whole wheat flour is made from whole groats. 


Brown rice is a rice groat, while white rice typically has the germ and most, if not all of the bran removed. “Polishing” refers to the removal of the bran. White rice cooks faster, is generally considered to be better quality for taste and cooking, but also has less fiber and nutrients than brown rice. All of the varieties of rice (jasmine, basmati, etc) exist as brown rice before being processed into white rice. 


There will be a forthcoming article explaining corn in more detail. Corn grits, cornmeal, and polenta are tricky, because the traditional forms and modern ones are called by the same name. It would be as if white flour and whole wheat flour were just referred to as “wheat”. Traditionally, the differences in milling corn landed into three categories: type of corn (dent, flint, etc.) coarseness of grind (grits, meal, and flour all refer to the size of particles) and whether or not the corn had been nixtamalized. “White corn” products were usually nixtamalized, while “yellow corn” products were not. Grits and polenta are both made with coarse ground corn, but from different species. However, once industrial milling became commonplace, the bran and germ were removed from corn. Grits and cornmeal still looked similar, but tasted different and were less nutritious. Typical cornmeal, polenta, or instant grits are all made from ground corn endosperm. “Traditional” grits or polenta, and some stone-ground cornmeals, are made from the whole corn kernel, leaving the germ and bran together with the grits. These products are usually coarser and take longer to cook, but many believe (ourselves included) that the flavor can’t be beat. 

Other Grains

Barley is treated a bit like rice: Hulled barley is a whole groat, while polished or pearled barley has the bran removed. Rye is generally found as a whole groat, or as whole grain flour. Many of the more exotic (for the North American table) grains are whole grains: quinoa, amaranth, teff, buckwheat, millet. It is rare to find these without endosperm, germ, and bran together.

Want to know more about particular grains? Hopefully, we will continue to post articles about specific grains, their histories, and recipes. Check out this flow chart for a more detailed explanation of different grains, which grains are related to one another, and what end products come from what grains. This is obviously not an exhaustive list, especially because common grains like wheat, corn, and rice have a tremendous variety of processing and consumption techniques throughout history.

Grain Flow Diagram_Double