Vino cotto ('cooked' wine) is a fragrant sweet ruby red dessert wine, made since the 3rd century BC by the Picentes in the Marche and Abruzzo, and is still made today, especially in the provinces of Ascoli Piceno and Teramo.
The grape must (many local varieties are used) is heated for hours over an open fire in a copper cauldron. The scum needs to be skimming off continuously, until the must is reduced by a half or a third, depending on the sugar content desired. Then it is mixed with raw must to ferment, then blended with old vino cotto and aged, sometimes for decades (like aceto balsamico). The older the vino cotto, the sweeter.
In Teramo, it is called Lu Bambinell ('the newborn')—a cask is made when a baby is born and drunk at his or her wedding. People have discovered barrels that had been hidden or walled up centuries ago, probably to keep invading armies or thieves from finding them with dregs of vino cotto on the bottom.
Little Loro Piceno is 'the capital of vino cotto' in the Marche, where it's celebrated in a festival in August.
Most vino cotto is made by families for their own consumption; according to EU regulations, it's not even allowed to be called 'wine' (because it is heated) although it is designated PAT.
Image by PD art