Roman cooking was well known for its excesses. While meals were often quite simple and basic in the early days of the Republic they eventually evolved into very elaborate affairs. The main meal of the day was the cena, which would usually begin at 4pm and often lasted late into the night. When guests were present, the meal could go on for hours. Diners were often entertained by acrobats and other professionals while they ate and meals were often made up of a number of different courses.
There were three main additives that were used in Roman cooking. These included carenum, defrutum and sapa. These ingredients were all made in much the same way. Grape juice or must was boiled down in pots so that water would evaporate. This left a liquid that could be used to sweeten or preserve various types of food and drink. Sapa was created when the liquid had reached one third of its regular volume. When half of the volume had been reduced, the liquid was known as defrutum. When only one third of the liquid remained, it was known as carenum.
The problem with these ingredients is that they were made in lead lined pots. This meant that lead acetate crystals would work their way into the liquid and were therefore consumed along with the food or drink. The lead was actually what caused the mixture to become sweet. When defrutum is made properly it can reach lead levels that are as high as 29,000 ppb. Drinking liquid that has this much lead in it can easily cause acute or chronic lead poisoning.
There were many rules that surrounded the making of defrutum. Pliny the Elder, a well-known Roman historian and author, felt that defrutum needed to be made during the New Moon. He also warned that defrutum should never be made in copper or bronze kettles. He felt that this would cause the defrutum to take on an unpleasant metallic taste.
Cato the Censor, a Roman statesman, felt that the quality of the grape juice would affect the taste of the defrutum. He felt that it was important to use must that was as sweet as possible and that boiling it in a lead pot was most important.
Defrutum was not just added to wine in order to make it sweeter. Romans would add it to meat dishes to make them sweeter. Some ducks and suckling pigs were fed defrutum in order to make their meat sweeter before being cooked. The most popular condiment in Rome, oenogarum, was made up of a mixture of defrutum and garum. Garum is a fermented fish sauce that was a staple of every day cooking in Rome. Defrutum and sapa were both used to preserve fruit such as quince and melon. Roman soldiers were often given food that had been preserved in defrutum as part of their standard rations. Roman women would often use defrutum or sapa as a cosmetic as well.
Because of the high levels of lead that are found in defrutum, it is now believed that this substance, along with the dishes used to eat and drink from, may have actually contributed to illness and the overall decline of the Roman Empire.