The article you linked says this: > The ancient Romans, who had few sweeteners besides honey, would boil must (grape juice) in lead pots to produce a reduced s

The article you linked says this: > The ancient Romans, who had few sweeteners besides honey, would boil must (grape juice) in lead pots to produce a reduced sugar syrup called defrutum, concentrated again into sapa But the article about defrutum adds more context: > However, the use of leaden cookware, though popular, was not the general standard of use. Copper cookware was used far more generally and no indication exists as to how often sapa was added or in what quantity. There is not, however, scholarly agreement on the circumstances and quantity of lead in these ancient Roman condiments.