The ancient Romans (roughly 8th century BC to 5th century AD) drank a lot of wine. Some historians estimate that they drank up to a liter of diluted wine per day, more than most people in the 21st century. A new study published in the journal Antiquity sheds new light on the wine’s flavor, aroma, and texture, Smithsonian reported on March 4. According to the study, Roman wine has a slightly spicy taste, with aromas of toasted bread, apples, roasted walnuts, and curry.

In the new study, the team looked at dolias, clay vessels that Romans used to store, ferment, and age wine. Historians have long known that dolias were widely used, but many questions remained about the details of their production. The new study shows that these vessels were essential tools in winemaking techniques. They were no ordinary containers, but precisely designed, with ingredients, size, and shape all contributing to successful aging.

Dolia was a key ingredient in ancient winemaking for hundreds of years, according to Dimitri Van Limbergen, lead author of the study and an archaeologist at Ghent University. Today, many wines are produced in stainless steel tanks and with added preservatives.

The Romans buried dolia jars up to the brim in the ground and sealed them with lids to regulate the temperature, humidity, and pH during fermentation, according to Van Limbergen and co-author Paulina Komar, an archaeologist at the University of Warsaw. The clay jars were porous and coated with tar on the inside, which helped tightly control oxidation.

The dolia had a narrow base, allowing the solids from the grapes to sink to the bottom of the vessel and separate from the wine, creating an orange color. But comparing this color to modern wines is difficult, because Roman wines were not divided into red and white wines. “Roman wines came in a wide range of colors, from white, yellow to golden, amber, brown, red and black, all depending on the type of grape used to macerate them,” explains Van Limbergen.

The conditions created by burying the vessels also influence the unique characteristics of the wine. Inside the vessels, yeasts grow on the surface of the wine, creating chemical compounds such as sotolon. These compounds give the wine its distinctive flavors and aromas.

“Ancient wines made from white grapes and using such techniques will certainly have an oxidized taste, with complex aromas of toast, dried fruit (eg apricots), toasted nuts (walnuts, almonds), green tea, with a dry and resinous feel (there are many tannin compounds in the wine from the grape skins),” Van Limbergen said.