Using Paleolithic conical mortars carved into bedrock, a team of experimental archaeologists has reconstructed how the Natufian people – hunter-gatherers who lived in the Levant region between about 12,500 and 10,200 years ago – processed wild barley to produce groat meals, as well as a delicacy that might be termed ‘proto-pita’ – small loaves of coal-baked, unleavened bread.

Top: map of Natufian sites with narrow and wide conical mortars in the Southern Levant. Bottom, from left to right: (i) almost peeled barley grain subsequent to the third shift of dehusking in the narrow conical mortar; (ii) grinding the dehusked grains to flour by intensive radial motion in a narrow conical mortar with a long wooden pestle; (iii) fine flour and some groats deposited in the adjacent cuphole, subsequent to the first shift of milling. Image credit: Eitam D et al.
Most scientists agree that cereal domestication was achieved about 10,500 years ago. The new study, published in the journal PLoS ONE, demonstrates how groat meals and fine flour were produced from wild barley, 2,000 – 3,000 years before the appearance of domesticated grains.
The authors – independent researchers David Eitam and Adiel Karty, and their colleagues from Bar-Ilan University and Harvard University – conducted the study at the Late Natufian site of Huzuq Musa in Jordan Valley.
Their field work resolved a long-standing mystery about thousands of cone-shaped hollows carved into the bedrock throughout the Southern Levant.
“The conical, human-made hollows, found all over Southeast Asia, were noticed by archaeologists decades ago, but there was no agreement about their function,” said Prof Mordechai Kislev of Bar-Ilan University.
“Assuming they were mortars used for the processing of plant food, we decided to use these ancient stone tools, along with period-appropriate items such wooden pestles, sticks and sieves, to reconstruct how the work was done.”
“The current study complements nearly 80 years of investigations suggesting that the Natufians – although subsisting as a hunter-gatherer society – used sickles to harvest wild, almost-ripe cereals, and were capable of producing large quantities of groat meals from roasted, ‘half green’ barley grain,” said co-authors Prof Ofer Bar-Yosef of Harvard University.
“Moreover, the technological advance from wide-to narrow-cone mortars represented a major dietary change, because de-husked flour made it possible to produce the fine flour needed for what has become the Western world’s most widespread staple food: bread.”
Prof Kislev pointed out that the barley-processing ‘facilities’ found at the site of Huzuq Musa indicate that stone-utensil-produced flour could have been a significant part of the local Natufian diet.
“Huzuq Musa is estimated to have had a population of about a hundred people,” he said.
“If we assume that the historical 35 liters of grain given to a Roman worker during the winter corresponds to a reasonable level of nutrition, the four large threshing floors discovered near the site – and its accompanying tools – could have produced a sufficient quantity of processed barley for its estimated inhabitants.”
“Producing food from wild barley grain was not easy, but the biggest challenge may have been the challenge of not harvesting all the wild grain in the field, and ensuring that there would be something left to eat the following year,” Prof Kislev said.
“This Natufian advance was a bridge to the Neolithic revolution, when sedentary farmers developed the discipline needed to plan for the successful planting – and reaping – of domesticated grains.”
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Eitam D et al. 2015. Experimental Barley Flour Production in 12,500-Year-Old Rock-Cut Mortars in Southwestern Asia. PLoS ONE 10 (7): e0133306; doi: 10.1371/journal.pone.0133306