There are different types of treacle, Black is only one, Golden Syrup is a lighter-coloured type of treacle and often substituted with corn syrup in recipes where black treacle is not available. In Britain, the main producer of black treacle (and Golden Syrup) is sugar refining company Tate and Lyle.
Roasted grapes are sophisticated. Toss grapes with olive oil, salt, and pepper, and roast them on a sheet pan for about 30 minutes at 425Â°F. The grapes will get blistered and caramelized on the outside, and extra juicy and practically jammy on the inside.
Making Grape Juice - Cooking off the Juice. Place cleaned grapes in a large pan (6-8 quart at least). Add enough water to just cover the grapes. Bring the grapes and water to a simmer, and maintain the light simmer for about 15 minutes. Try not to bring them to an actual boil, because they can boil over pretty easily.