Christopher Beattie

The Romans put lead in their wine on purpose, because it made it sweeter. The method is written down in Cato, Columella and Pliny. In the autumn, unfermented grape juice went into a cauldron over a slow fire and was stirred for hours until it boiled down to a half, which they called defrutum, or a third, which they called sapa. Pliny advised doing it when there was no moon, with a few walnuts thrown in to soak up the smoke. Columella was precise about the pot. Use lead, he wrote, because a bronze one throws off a green rust that spoils the flavour. What the lead actually did was dissolve. The acid in the grapes ate into the cauldron and came out as lead acetate, a compound so sweet that later chemists named it sugar of lead. Roman cooks could taste the difference, and the lead pot won. Sapa went into the wine to sweeten and keep it, over pears and quinces, into the sauces. Scores of recipes in the cookbook of Apicius call for it. Chemists who have boiled it up the Roman way have found between a quarter of a gram and a full gram of lead in every litre. Mixed at Columella's own proportions, that puts around 20 milligrams in a litre of finished wine, about two thousand times the legal limit for British tap water. The people drinking the most of it were the ones rich enough for good wine and fancy cooking. Slaves and legionaries drank posca, sour wine cut with water. Rome was warned. In the reign of Augustus its greatest engineer, Vitruvius, wrote that water from clay pipes was far more wholesome than water from lead, and pointed to the plumbers, whose skin had gone a deep, deathly pale. Pliny called the vapour off a lead furnace deadly. The cauldrons stayed. Nobody wanted to go back to sour wine. And the rest of the empire got its dose anyway. In 2025 scientists working through the layers of the Arctic ice found Rome's lead in it. Mining and smelting silver for the coinage had put so much into the air that children's blood lead rose right across Europe, enough, they calculated, to take 2.5 to 3 IQ points off the whole empire. Britain repeated it in the 1700s. Every autumn the cider country of Devon came down with gripping colic, then palsy. In 1767 a Devon vicar's son, Dr George Baker, showed that the county's cider presses were lined and jointed with lead, found lead in Devon cider and none in Herefordshire's, and read his paper to the College of Physicians. Devon called him a faithless son of the county. His critics said the lead came from shot left in the bottles and the colic from acid humours. The lead came out of the presses anyway, and within a generation the Devon colic was all but gone. Rome ignored Vitruvius. Devon called Baker a traitor. The petrol industry cut Clair Patterson's funding and kept him off the national panel on lead. Every age has a sweetness it will not give up, and a Vitruvius it would rather not hear.