Kir
Royal

One centiliter of crème de cassis to 10 cl of champagne is the classic measure, or about one-tenth. Two centiliters is possible, but then the Kir Royal shifts toward dessert and the dryness of the bubbles disappears. In France, it is often dosed even more sparingly, with barely half a centiliter at the bottom of the glass. Pour the cassis into the flute first, then slowly top it up, because stirring is unnecessary: the heavier liqueur mixes by itself and creates the color gradient along the way. If you do it the other way around, the champagne will foam over the rim.

Around 12 percent, so comparable to a glass of wine. The 10 cl of champagne at approximately 12 percent provides 1.2 cl of pure alcohol, and the centilitre of cassis at 16 to 20 percent adds a fraction more. A full flute therefore contains about 1.4 cl of pure alcohol, slightly more than one standard drink. No ice or water is added, so dilution is not a factor here: what you pour is what you drink. With crémant or prosecco instead of champagne, the percentage hardly changes.

The basics. A regular Kir is made with dry white wine, traditionally aligoté in Burgundy, while a Kir Royal is made with champagne or crémant. That's all, because the cassis and the ratio remain the same. This makes the Kir the everyday aperitif and considerably cheaper, while the Royal is the festive version with mousse and a gradation of colour. There is a third version too: the Kir Communard, made with red wine instead of white. Félix Kir himself served the simple version, with local wine and local liqueur, and only later saw his name become associated with sparkling wine.

Choose a crème de cassis de Dijon with 16 to 20 percent alcohol, because cheap cassis syrup or fruit liqueur tastes jammy and smothers the bubbles. Brands such as Lejay, Gabriel Boudier and Briottet are widely available in the Netherlands. The bubbles don't have to be champagne: a crémant de Bourgogne is the most authentic choice and costs about half as much. Prosecco works too, but choose brut rather than extra dry, because the latter is sweeter than its name suggests. Keep the bottle at 6 to 8 degrees and serve it ice-cold.

What is Kir Royal in one sentence: a French aperitif made with crème de cassis topped up with ice-cold champagne or crémant, served in a narrow flute. As a Kir Royal cocktail, it belongs at the start of the evening, before the meal, because the cassis stimulates the appetite without being filling. Only pour it once everyone has arrived, because a flute left standing for ten minutes will already have lost its mousse. If you don't have flutes, choose a narrow wine glass rather than a wide coupe glass, because the bubbles disappear faster in a wide bowl.

The Kir Royale recipe is easy to scale up: a 75 cl bottle of sparkling wine makes seven 10 cl glasses, so allow for seven centiliters of crème de cassis in total. Do not mix anything in a carafe, as the mousse disappears within minutes. Instead, prepare the flutes with the liqueur already at the bottom and only pour in the bubbles when your guests sit down. This keeps every Kir Royale cocktail just as fresh and lets everyone see the color gradient appear. Return the bottle to the cooler in between.