A pressing matter: Ancient Roman food technology

No self-respecting Melbourne hipster café would be caught dead without its Gaggia coffee machine and drizzled olive oil and balsamic vinegar. These quintessentially Mediterranean food habits have crossed the seas through trade, immigration, and technological diffusion – a pattern which would not surprise an ancient Roman.

The Romans transported wine and oil across the Empire in thousands of trade ships, by mule and ox-cart, and by camel on desert tracks, and established the vineyards of Bordeaux and the Moselle and mass olive production in Spain.

In some ways their world seems startlingly modern – a cultural, religious and technological melting pot which produced major innovations such as the waterwheel and central heating. Yet technological change did not follow the rapid modern pace of uniform innovation and almost instant obsolescence of old machines.

My work piecing together the jigsaw of when, how, why and by whom food technology changed, using archaeological and ethnographic evidence, has overturned nearly a century of assumptions, highlighting the sometimes diverse and local nature of specific ancient technologies. It has also resulted in a new translation of a key ancient text.

No technical drawings

How exactly did agricultural innovations spread in the ancient world? Without printing, books were expensive, and produced only in very small numbers – a few hundred copies, perhaps. The common people ­– who actually built machines – seem to have been able to write a memo or scrawl a graffito, but it is doubtful whether most could have read detailed instructions.

The Romans also lacked technical drawings. The classic example of trying to describe in words how to tie a shoelace teaches us a serious lesson in the importance of technical drawing to the history of technology. The development of scaled drawings and diagrams were vital to the spread of technologies in the 17th and 18th centuries, but Roman mechanical treatises such as those of 1st century BCE Roman technical writer Vitruvius seem to have been only scantily illustrated, if at all.

Engineers travelled with the army, objects such as glass were traded and imitated, and migrating artisans working in luxury crafts such as gold-smithing spread their skills. But innovation in food production was different. As part of the Oxford Studies in the Roman Economy series, I have investigated the pressing machines used in making wine and oil, two vital food staples of the ancient world. These machines were huge – up to 12 metres long, and 3-4 metres high, weighing many tonnes – and never transported.

They were built not by the army or specialist artisans but by the rural population, using local stone and wood. In farms and villages throughout the Mediterranean, the pressing of olives or grapes was the focus of both frenetic labour and joyful celebration of harvest throughout many centuries.

An 80 year-old mistake

Our only detailed Latin description of these machines is by Pliny, a tireless investigator who was killed observing the AD 79 eruption of Mount Vesuvius which destroyed Pompeii. Based on this description, historians since the 1930s have imagined a uniform and linear evolution of press technology, with two successive innovations: the introduction in Greece of a carved wooden screw, which replaced ropes and winches as the means of operating a heavy lever which pressed olives or grapes; and then its replacement by a smaller press, without a lever, in which the screw itself pressed down on the fruit.

But this interpretation is coloured by 20th century post-industrial assumptions, and is manifestly untrue when tested against the recent finds of archaeology. In a research collaboration with Dr Paul Burton of the Australian National University, to be published in the German journal Klio in 2019, we have reviewed Pliny’s text in the light of this new evidence, and found that his words have been misunderstood and mistranslated for more than 80 years.

Pliny does not say that each new press replaced the one before, but only gives the date at which each first came into use. He does not say that the screw presses were ‘Greek’ (Graeca), but rather that the screws used were ‘Greek-style’ (Graecanica), referring to the earlier invention of a continuous screw used in water-lifting devices by the Sicilian Greek Archimedes. He does not say that large levers were replaced, but that smaller presses were more suitable for farms with smaller buildings. A close reading of his text makes clear that he is describing many parallel technologies, not a sequential evolution.

The archaeological evidence of press remains demonstrates that screw presses were not introduced from Greece, where they were not used until nearly 400 years after Pliny.

Diverse and localised innovation

The evidence reveals a great diversity of regional types throughout the Empire, and that old types continued to be used over many centuries. The invention of new variants seems to have been generated within local communities, developing on the basis of regional skills and materials, and continuing tried and tested local practices with innovative improvements.

For example, in Israel, where local forms of stone supports with slots to adjust the height of the lever had developed, these supports were adapted for use with the new screw-operated lever. In southern France, where single squared blocks of stone had long been winched by rope to weight a lever, these were sometimes reworked to be raised more easily by a screw.

At many sites, the older methods of hanging heavy stones on the lever were continued alongside or in combination with the new, because they were effective, the materials were at hand, and a communal investment had already been made in long-lasting components.

Indeed, traditional types of presses, often hundreds of years old, were still in use up to the mid-20th century. Anthropologist John Gulick describes a Lebanese village of the 1950s where a traditional olive press was still used alongside modern machines, because the new presses were “apparently, less fun to operate”.

The true history of the wine or olive press is a story of traditional skills embedded in local communities, passed on through many generations, renewed through innovation but not wantonly discarded for the latest new thing.

Oil and wine pressing was a time of cooperative effort and communal celebration, of connection with the past and hope for the future, and even – in spite of hard work, or perhaps because of it – fun.

Banner image: Roman sarcophagus relief, 3rd century, showing men turning a screw to raise the weight-stone of a press similar to that described by Pliny. Museo Archeologico Nazionale di Aquileia. Picture: Courtesy J. - P. Brun.