Gastroarchaeology, the study of our ancestors’ cooking and eating habits, has a long history. Based initially on animal bones, the recent systematic recovery of plant remains and even coprolites – fossilised faeces – has led to a more broad-based understanding of ancient diets.

Our earliest forebears seem to have scavenged for meat from carnivore kills, collected fruits and seeds, and grubbed for roots: some ten millennia ago people in the Middle East began to grow wheat, barley, lentils and other cereals and pulses, and domesticated sheep, goats, cattle and pigs to eat, and then for milk, cheese, and wool. In the Americas, maize was the staple crop, while few animals were domesticated, even by the time of the Spanish Conquest.

Several recent studies have expanded our understanding: in northern Greece, a burnt-down house has preserved what are claimed to be the oldest known grapes, and the earliest evidence for wine.

Excavations at the site of Dikili Tash, near Drama in Greek Macedonia, have revealed four late-Neolithic rectangular houses destroyed in a conflagration between 5000 and 4500BC. “They contained ovens, storage bins, pots, and a wide variety of objects related to daily activities”, Dr S. M. Valamoti and colleagues report in Antiquity.

The plant remains recovered included wheat, barley, lentils, peas, figs, acorns and wild pears. On one of the floors were some 2,500 grape pips and more than 300 empty, pressed grapeskins: the size of the pips suggested that the grapes were either wild or at a very early stage of cultivation.

Experimental charring of modern wine pressings yielded similar remains, distinct from those of charred fresh grapes and raisins. “We can therefore conclude with some certainty that the concentration of grapes found at Dikili Tash represents the byproducts of extracting juice from grapes,” the investigators say.

Although grape juice in historic Greece has been boiled down and used to make sweets, given the bitter taste of wild grape juice “it might have made more sense to produce a fermented beverage rather than a syrup,” they say, with figs or honey being used to sweeten the wine.

It seems likely, they argue, that wine-making preceded domestication of grapes: pottery vessels from the burnt houses at Dikili Tash included two-handled cups and jars suited to decanting and drinking. Cups from another and slightly earlier Greek site, Makriyalos, were associated with feasting, and analysis of their contents would be worthwhile.

The Greek grapes antedate by several centuries the recent discovery of evidence for wine at Erimi in Cyprus, and it seems likely, the team agrees, “that wine production, viticulture and the domestication of the grape could have taken place independently in various parts of the grape vine’s natural distribution”.

The spice of life

Chilli peppers have long been a staple of Mexican and other Latin American cuisines, their spicy heat adding zest to the blandness of maize and cassava (manioc) dishes, as well as being a useful antispasmodic in diets heavy on such carbohydrates.

The seeds are tiny and the flesh does not preserve well, but Dr Linda Perry has now discovered that ancient chilli peppers can be detected from their starch content. Noting that chillies sometimes cause indigestion – as anybody who has eaten an authentic Mexican meal can attest – and that undigested starch also causes the condition, Perry was able to identify a mysterious and widely occurring starch type from archaeological sites as the tracer for peppers.

Writing in Science, Perry’s Smithsonian Institution team place the oldest chilli so far known in Ecuador around 6,100 years ago, where they formed part of a diet that included maize, cassava, squash, beans and arrowroot, many of them rather bland foods. In Panama they go back some 5,600 years, in Peru 4,000 years.

Not all peppers were of the same species, and those in Mexico and the Maya lands are distinct from those in South America. The wide variety of chillies, and their varying capsicin content – which gives a spiciness ranging from the anodyne to the apocalyptic – suggests a long history of experimental domestication now borne out by Perry’s results.

In a stew

Another discovery in the New World has shown how normal recovery methods for ancient food remains may be misleading. The Maya of Guatemala, Belize and the Yucatán peninsula of Mexico have long been known to have a diet with maize as the cereal staple, complemented by beans and squashes, with deer and other wild animals as the main source of protein.

Root crops such as sweet potato and cassava were thought to be unimportant until Dr Jon Hather, of University College London, showed in the 1990s how their remains could be recovered from ancient middens.

Freshwater fish were also thought to be a negligible contribution to protein intake, since few of their bones were found.

Dr Shannon Coyston of McMaster University in Canada has now shown that this might be wrong: examining baked-on food on the insides of 2,500-year-old cooking pots from the early Maya village of Cuello, she used stable isotopes of carbon and nitrogen to see what had been allowed to burn.

“Most of the vessels were not used to prepare maize,” she reports. “Elevated nitrogen values clearly indicate that freshwater fish were prepared in them,” while “depleted carbon values and the thickness of the chars on these same vessels suggest that a starchy plant was cooked along with the fish”. Analysis of lipid residues corroborated the nitrogen results, while Hather’s identification of cassava and another Native American root crop, Xanthosoma, or malanga, from their fibrous remains suggests the starchy component.

Such a fish and starch stew is still made in Belize, where it is called a “boil-up”, although now in Creole rather than Maya cuisine. Dr Coyston’s work indicates a prehispanic ancestry, and adds another dish to the Ancient Maya menu.