
Berry cordial is a sweetened berry concentrate, diluted or dosed into a drink. Which berry is up to the maker, since the name covers a family and not one product.
A syrup of the same berry is the nearest thing on the shelf, and it carries the fruit without the acid — the drink then wants its lemon kept up. Another red berry matches the color and moves the sourness: raspberry and strawberry come sweet, redcurrant and cranberry sharp.
Berry liqueur
Alcoholic and far less sweet: it brings the fruit but rewrites both the sugar and the strength of the drink.
Grenadine
Pomegranate, not berry, and tannic against a berry cordial’s fruit; it colors the same and tastes noticeably drier.
Fruit cordials are the ones that ferment. Keep it cold, keep the bottle clean, and watch for a fizz or a yeasty smell — that is the sign to discard it rather than a stage it passes through. Two to three weeks refrigerated for homemade.