Bread, in all its various forms, is the most widely consumed food in the world.

Bread, in all its various forms, is the most widely consumed food in the world. Not only is it an important source of carbohydrates, it’s also portable and compact, which helps to explain why it has been an integral part of our diet for thousands of years. In fact, recent scholarship suggests humans started baking bread at least 30,000 years ago.

Prehistoric man had already been making gruel from water and grains, so it was a small jump to starting cooking this mixture into a solid by frying it on stones. A 2010 study by the National Academy of Sciences discovered traces of starch (likely from the roots of cattails and ferns) in prehistoric mortar and pestle-like rocks. The roots would have been peeled and dried before they were ground into flour and mixed with water. Finally, the paste would be cooked on heated rocks.

But how did humanity get from this prehistoric flatbread to a fluffy, grocery store loaf? There were three primary innovations that created “modern” bread.

1. Leavening

Leavening is what makes bread rise into a light and fluffy loaf. Bread without leavening is a known as flatbread, and is the most closely related to mankind’s first breads. Examples include Middle Eastern pita, Indian naan and Central American tortillas.

The most common leavening for bread is yeast. Yeast floats around in the air, looking for a nice place to make a home—like a starchy bowl of flour and water. The first leavened bread was likely the result of some passing yeast making a home in a bowl of gruel. The yeast began eating the sugars present in grain, and excreting CO2, producing bubbles that resulted in lighter, airier bread. Commercial yeast production dates back to the skilled bread makers of Ancient Egypt around 300 B.C.

2. Refined Flour

The earliest bread grains would have been ground by hand with rocks. This would have resulted in coarse, whole grain bread—the descendants of which are dark, rustic breads from Europe, like pumpernickel. The Mesopotamians refined this process around 800 B.C., using two flat, circular stones, stacked on top one another to grind the grain. These stones were continuously rotated by draft animals or slaves. This “milling”—which was the genesis for how we create flour today–created smooth, finely ground flour that quickly became prized as a status symbol. The desire for the whitest, most refined bread continued through the modern era, and later advancements included the sifting of flour to remove the bran and the germ and the bleaching of the flour itself.

3. Mechanized Slicing.

For hundreds of years, the finest white breads were sold in whole loaves to be cut at home—like a French baguette. The New York Public Library’s “Lunch” exhibit notes: “Nineteenth and early 20th-century cookbooks and magazines gave highly specific advice about lunchtime sandwich making. For ladies and children, the bread was supposed to be sliced very thinly and the crusts removed. For workers, thick slices with crusts were deemed more appropriate.”

But in 1917, itinerant jeweler Otto Rohwedder created the first mechanized bread slicer. Initially, many companies were convinced that housewives wouldn’t be interested, and his bread-slicing machine wasn’t installed in a factory until 1928. However, within two years, 90% of store-bought bread was factory sliced.

Progress led us to what was supposed to be the ideal loaf of bread: white, ultra-fluffy and pre-cut into even slices. This perfect bread was dubbed “American.” By this standard, Wonderbread should have been the last loaf of bread we ever needed. But modern science has uncovered the nutritional benefit of whole grains, and more and more consumers prefer the toothsome texture and nutty taste of a rustic loaf.

If you feel inspired to replicate a prehistoric recipe like I was, I’ll warn you that Bob’s Red Mill does not make a “Cattail/Fern Blend Flour”—yet. Settle for a “10 Grain Breakfast Cereal” full of ancient grains, like millet, coarsely ground.

Then, visit your local home improvement store, and poke around the slate tiling. You may be able to nab a few pieces of broken tile for free. Or, if you live somewhere they are easily accessible, simply walk outside and pick up a flat rock.

Now, you need to build a big fire. (That’s what I did at the Old Stone House of Brooklyn, a historic site that’s surrounded by children’s park.)

Let the flames die down until you have a bed of glowing, hot coals. Set the slate tiles on top of the coals, and wait about 10 minutes. Combine three cups of grain with about a cup of water and mix into a thick, workable paste. Form the dough into one-inch thick patties, and place them on the stones. After five minutes, flip them with a piece of bark—and you’ll be amazed to see the grain is browning on the heated rock. They may stick, so I recommend greasing your cooking rocks before hand.

In about 10 minutes, you’ll have a pile of hot, crispy cakes. The outside is crunchy and tastes like popcorn, the inside is moist and dense. I fed one to one of the children in the park, who described it as “pretty good,” though it’s possible she was just being nice.