I'm putting this on my bread blog, because of course I am. Also tagging @appendingfic who I think expressed interest.
Tens of thousands of years ago people foraged and hunted for their food and ate whatever they could. Among their forage were wild cereals, which included the ancestors of modern cultivated wheat, barley and others.
People like sweet things. Grains are starchy, but if sprouted they start converting those starches to sugars, so people would've left grains in water to sprout. These sprouts are also easier to digest, thus more nutritious, which bestowed an invisible advantage on those sprouting their grains.
If grains are left in water too long, however, they begin to ferment. Alcohol is produced. People like alcohol.
In ancient Mesopotamia the fermented grains were experimented with, resulting in an early form of beer. The process of making that beer was quite complicated and involved a combination of sprouted and mashed grains.
People wanted beer all year round, but early beers did not have long shelf lives and the grain could only be harvested at certain times. So the ancient Mesopotamians invented a way of storing the ingredients for beer.
It was made of the grain mash, honey, dates and spices that were fermented to make beer. For storage, prior to fermentation, the mixture was baked dry, cut into smaller pieces and baked again to remove all water. This produced bapir, a product very much like biscotti, which could be stored for later rehydration and fermentation. Sometimes it was eaten instead.
I've made bapir, and I've eaten it. It is brittle but delicious. It's also a form of unleavened bread.
Bread was invented as a way to store the ingredients for beer, which was most likely a development from a chance discovery. Leavened bread (that is, with bubbles) may well have been discovered when a mixture like that for bapir was accidentally allowed to ferment before baking. Yeast is responsible for both alcohol production and leavening.
There's a lot more to it, in terms of the cultivation of grains and the development of milling, than I've written here. It's been a process of millennia to go from chewing sprouts to eating soft white bread like that pictured. But every step along the way was small and simple.
