Doc,
Defrutum was typically made by boiling grape juice in a lead pot to half it's volume. This was used as a flavor syrup enhancer. It could contain as much as 29 ppm of lead. That's unhealthy no matter how little was added.
29 ppm is kinda low, i seen numbers estimated up in the 1000 mg/liter range but those claims are quite outre' however lead acetate has also been asserted to be biologically unavailable (dont ask me how) leaving the finished product with almost no free lead in solution (again ?? magic?) but still you would have to tear up a shitload of defrutum to get much lead through your food.
most romans didnt use the stuff, just a few gourmands who enjoyed violating the sumptuary laws.
romans loved sweet things, but not super sweet wines. when they wanted sweet things they usually went with honey. pewter tableware and lead lined aquaducts, pipes and cisterns in the homes of the rich were archeologically verified sources of lead.
when mixed with water 50/50 (as was the custom) sweet wines taste like piss, and cold piss at that. sour or tangy wines are not too bad though.
also, not the juice, "must". the crud left over after pressing for wine, mostly skins, and solids. the stuff they make grappa from these days. mmmm Grappa. i believe Cato had a recipe for defrutum i been meaning to try (hold the lead please) imma look that sucker up.
EDIT: nope, cato had the bomb recipe for Coan (raisin wine)
Columella had the recipe for defrutum.
checkem
"Some people put the must in leaden vessels and by boiling reduce it by a quarter, others by a third. There is no doubt that anyone who boiled it down to one-half would be likely to make a better thick form of must and therefore more profitable for use....But, before the must is poured into the boiling-vessels, it will be well that those which are made of lead should be coated inside with good oil and be well-rubbed, and that then the must should be put in....The vessels themselves in which the thickened and boiled-down must is boiled should be of lead rather than of brass; for, in the boiling, brazen vessels throw off copper rust [
aerugo], and spoil the flavour of the preservative....Must of the sweetest possible flavour will be boiled down to a third of its original volume and when boiled down, as I have said above, is called
defrutum"
you can see the lead kettle is oiled, reducing the amount of lead in the solution.
imma cook this shit tomorrow (in stainless steel)