It is known that in early historical times various peoples enjoyed eating porridges--stewed grains of various types, flavored with spices and additions such as onions, fruit, or small amounts of meat. For example, it is said that the Roman legions objected strenuously if their favorite meal of porridge was not available.
But the eating of porridges and other boiled starch sources go much farther back in human history, according to archaeologists. Research has revealed that the development of porridge happened early in human history. It was also critically important, as it enabled humans to obtain glucose--the human body's fundamental fuel--from plants.
Dr. Amanda Henry, a paleobiologist and associate professor at Leiden University in the Netherlands, heads a project called HARVEST, which is researching why and how early humans ate plant material. Horizon magazine recently published an article about the research by HARVEST and by a different project called HIDDEN FOODS; that article can be read here.
Contrary to some moderns' beliefs about the "paleo" diet, paleolithic people ate tubers and grains--they needed whatever calorie sources they could find. According to the Horizon article, the earliest plant material eaten included wild tubers, such as water lily tubers, and wild grains. Grains might have been eaten young (and raw) sometimes, but tubers are often poisonous unless cooked, and there is some archaeological evidence that at least some foods were boiled before being eaten. Archaeologists can tell whether a plant was eaten raw or cooked by examining starch grains in the dental calculus (i.e., plaque) on the teeth of human skeletal remains. In addition, cooked tuber remains have been found in the remains of a fireplace in South Africa that is over 100,000 years old. The use of flour made by grinding up things like acorns, wild oats, and legumes goes back at least 30,000 years, according to evidence found in Russia, the Czech Republic, and Italy.
What is important about this evidence is that it confirms the date of the fundamental discovery that boiling starchy plant matter such as tubers and grains makes it possible for the human body to use the glucose they contain. Of course, paleolithic people didn't know about glucose, but they surely knew that after boiling, plant matter often became filling, perhaps even palatable.
Today, many people turn up their noses at boiled root vegetables and porridge. But the discovery that tubers and grain could be eaten once boiled was critical to human survival--it made a new source of glucose available and enabled people to survive longer and breed more. It is a key development in the history of food.