Conor Trainor, University College Dublin

Before artificial sweeteners, people satisfied their cravings for sweetness with natural products, including honey or dried fruit. Raisin wines, made by drying grapes before fermentation, were particularly popular. Historical records show these wines, some known as passum, were enjoyed in the Roman Empire and throughout medieval Europe. The most famous of raisin wine of the period was Malmsey, with varities of this type produced across the Mediterranean.

Today, the popularity of raisin wines has declined, although some still are held in very high esteem. The best-known of these are Italy’s appassimento (literally “withering”) wines, such as Amarone. High-quality modern raisin wines from the Veneto region of Italy are left to dry for three months before being pressed and undergoing fermentation, a time-consuming process.

Ancient sources describe similar techniques for producing raisin wines. Columella, a Roman agricultural writer, noted that drying and fermentation together took at least a month. The Roman author, Pliny the Elder, mentioned a process in which grapes were partially dried on the vine, then further dried on racks before being pressed eight days later.

For the past ten years, I have been studying the process of how this wine was created at the archaeological site of Knossos in Crete. While famous for its earlier, Minoan, remains, Crete was renowned throughout the Roman empire for producing high-end sweet raisin wine, which was traded far and wide.

Looking for something good? Cut through the noise with a carefully curated selection of the latest releases, live events and exhibitions, straight to your inbox every fortnight, on Fridays. Sign up here.

High-quality raisin wines required patience and time but it seems as if Knossos’s wine producers might not have been following these traditional methods.

What my archaeological investigations of a wine production site, as well as at wine shipping container (amphora) production sites at Knossos, is that Cretan wine-producers may have been deceiving their Roman-era customers with a knock-off version of passum.

Crete’s winemaking legacy

Remains of a wine production facility in Knossos present a picture of winemaking practices a generation or so before the Romans conquered Crete. More intriguingly, ongoing studies of excavated Roman-era pottery kilns revealed a repeated pattern of four key artefacts being produced in one region of Knossos: amphorae for transporting wine, amphora stands for filling them, large ceramic mixing bowls, and ceramic beehives.

Crete, the largest Greek island, has been producing wine for thousands of years. Archaeological evidence from Myrtos suggests winemaking as early as 2170 BCE. Its strategic location between Greece and North Africa made it a valuable asset and in 67 BCE, after a brutal three-year campaign, the Romans conquered the island.

Following the conquest, Crete’s economy underwent major changes. The Romans established a colony at Knossos, transformed the governance system, and significantly expanded wine production. Rural activity surged, and archaeologists have found large numbers of amphorae (clay jars used for transporting wine) suggesting that Cretan wine was exported in huge quantities.

Romans bought so much Cretan wine partly because of shipping routes. Grain shipments that helped feed the people of Rome frequently stopped at Crete en route from Alexandria to Italy, allowing merchants to load additional cargo. But demand was also driven by the reputation of Cretan raisin wine, which was considered a luxury product, much like Italy’s appassimento wines today. Beyond taste, it was also valued for supposed medicinal properties. The Roman army physician Pedanius Dioscorides wrote in his famous five-volume medical work Materia Medica that the wine cured headaches, expelled worms and even promoted fertility.

The sudden rise in demand for sweet Cretan wine in Rome and on the Bay of Naples in the early days of empire may have encouraged winemakers to speed up production.

Pliny the Elder described one shortcut for making raisin wine – boiling grape juice in large pots. However, the mixing basins found at Knossos show no evidence of heating. This suggests another possibility: adding honey to wine before packaging. The beehives, excavated from Roman-era pottery kilns and identifiable by their rough interior surfaces designed for honeycomb attachment, hint at a connection between winemaking and honey. Similar discoveries at other Greek sites suggest that honey and wine may have been mixed before shipping.

This method would have been quicker and cheaper than drying grapes for weeks. But if Cretan producers were substituting honey for traditional drying techniques, was this truly raisin wine? And, were Roman consumers aware? The vast quantities of Cretan wine imported into Rome suggest that buyers weren’t too concerned either way. Based on the sheer volume of now-empty wine amphoras from Crete that have been found in archaeological sites in Rome, I suspect that the populous of Rome likely cared less about authenticity than we do today.

Conor Trainor, Ad Astra Research Fellow / Assistant Professor, University College Dublin

This article is republished from The Conversation under a Creative Commons license. Read the original article.