
Pomegranate juice is pressed from the arils of ripe pomegranate — deep red, sweet-tart and slightly astringent.
Cranberry juice is the nearest supermarket bottle, same measure, sharper and thinner — a teaspoon of pomegranate molasses stirred in restores the depth it lacks. Most red juices bring the color and the tartness and leave out the tannin, so the glass looks right and drinks thin.
Grenadine
A syrup, not a juice: sugar-led, thicker, and used by the spoonful. Pouring juice where grenadine was meant leaves the drink pale and dry.
Pomegranate molasses
Cooked down to a thick, sharply sour paste used in cooking; it is far more concentrated than either, and a teaspoon changes a drink.
Fresh juice keeps two or three days refrigerated and loses color before flavor. Bottled keeps to its date and belongs in the fridge once open. It stains everything it touches, cloth and wood especially.