Black Forest Cake (Schwarzwälder Kirschtorte)

Kirschwasser (literally 'cherry water') is a clear, dry, un-sweetened cherry brandy distilled from fermented whole cherries. It has a clean, tart, faintly floral cherry flavour with no sweetness and about 40% alcohol. It is the defining ingredient of Schwarzwälder Kirschtorte — German regulations state the kirsch flavour must be clearly noticeable. Substitutes in order of preference: cherry eau-de-vie (similar product from France), slivovitz (plum brandy, different but good), rum (available everywhere, different flavour but works). For a non-alcoholic version: use the cherry syrup from the jar to soak the layers and add a teaspoon of vanilla or almond extract to the filling. The result will be good but noticeably different.

Jarred morello cherries (Schattenmorellen in German) in syrup are the standard and most practical choice. They are already pitted, the syrup provides liquid for the filling, and their consistent sourness works well with the sweet cream and kirsch. Fresh sour cherries work well in summer when available — pit them and macerate with a little sugar. Frozen sour cherries: thaw completely and drain well before using. Avoid sweet cherries (too mild and they become cloying with the cream and sugar) and maraschino cherries (too sweet, artificial flavour). The sourness of morello cherries is not incidental — it balances the richness of the whipped cream and cocoa.

The egg-separated method beats the whites to stiff peaks separately, then folds them into the yolk-sugar mixture. The beaten whites contain millions of tiny air bubbles trapped in protein networks. When folded into the batter, those bubbles expand in the oven's heat, creating a structure that is significantly lighter than a whole-egg creamed cake. The folding must be done gently and in stages — vigorous mixing deflates the whites and the resulting sponge is dense. The cocoa and flour are folded in last, minimally, just until no white streaks remain. The melted butter goes in at the very end and is folded quickly.

Three things improve with overnight resting. First, the Kirschwasser brushed onto the sponge layers absorbs fully — a freshly assembled cake has detectable wet patches; after overnight resting, the spirit has distributed evenly and mellowed. Second, some cherry juice migrates slowly into the cream layers, tinting them faintly pink and adding flavour. Third, the cream firms up and the layers compress slightly, making the cake easier to cut cleanly and giving the interior a more cohesive, settled character. This is why professional German bakeries that make Kirschtorte bake the components the day before and assemble and deliver the same morning.

Use double cream with at least 35% fat — lower-fat creams whip but do not hold shape well. Beat in a chilled bowl. Stop at soft to medium peaks — the cream should be firm enough to pipe but still have a slight wobble when the bowl is tilted. Over-whipped cream becomes grainy and eventually separates. If stabilised cream is needed (for very warm conditions or multi-day storage), dissolve 1 teaspoon of gelatine in 2 tablespoons of warm water, cool to room temperature, and beat into the cream near the end of whipping. The assembled cake can be kept refrigerated for 2 to 3 days; the cream maintains its shape well under refrigeration.