Grenadine: what it is, what to pair it with, and how to pick a good one
Quick answer: grenadine is a sweet-tart syrup made from pomegranate juice, giving cocktails their red colour and a light tartness. Classic uses include Tequila Sunrise, Dirty Shirley, and colouring the layers in shots.
A good grenadine is made from real pomegranate juice or concentrate — the colour should be a rich ruby, not a bright artificial red. The taste should be sweet-tart with a light tang, without a fake "bubblegum" note.
What to pair it with: citrus (lime, orange, grapefruit) plays up grenadine's tartness, vanilla and coconut soften it, and soda or sparkling water keep it light. In stronger cocktails, grenadine works well with rum, tequila and vodka.
Proportions: 10–15 ml of grenadine is usually enough for a 200 ml cocktail — it's mostly an accent, not the main ingredient. For a gradient effect (as in a Sunrise), pour the grenadine last, carefully, down the side of the glass or over a spoon — it's heavier than most juices and will settle at the bottom.