What Makes Black Forest Cake Unique?

Germany is famous for its fantastic beer, irresistible döner kebabs, and crispy schnitzels, but its sweet treats deserve the same praise and recognition. Although many German desserts may be unfamiliar to you, there is likely one that does ring a bell: Black Forest cake. Black Forest cake is magnificent to behold, with its layers of soft chocolate sponge and pillowy whipped cream, adorned with beautiful cherries and chocolate shavings. Known in German as Schwarzwälder Kirschtorte, the Black Forest cake is thought to have originated in the 16th century in the Black Forest — "Der Schwarzwald" — a region in Germany.

In this region, the secrets to the Black Forest cake are unlocked. The cake's incredible depth and unique flavor are due to a sour cherry brandy called kirschwasser, or kirsch. The baked chocolate sponge is soaked or brushed with the brandy, giving the cake an incredible moistness and indulgent flavor. To elevate this cake further, kirsch can also be infused into cherry syrup or whisked into a gorgeous chocolate ganache. At its heart, the Black Forest cake is a celebration of chocolate and sour cherries.

Kirschwasser means cherry water, and it's a delectable brandy made by fermenting the juice of sour morello cherries and then distilling that juice twice. It's a clear liquor with subtle cherry notes that's typically 40% ABV, which means it packs a bit of a punch. Store-bought, it's usually not overly sweet but instead holds a bitter almond backdrop in flavor. It is believed that during the Ottoman Empire's expansion, the distilling process became widespread in Europe, and the Black Forest region began to create fruit brandy. Centuries later, it's now the refined ingredient that makes Black Forest cake what it is today.

The amounts of kirsch used in Black Forest cake can vary; you can brush 2 tablespoons of kirsch over each layer of cooled chocolate sponge or infuse it into a syrup. The latter approach involves creating a simple cherry jam from fresh (or frozen) cherries and sugar. Once this has reduced and the cherries have released their juice, the mixture is pressed through a fine-mesh sieve. The syrup is caught in a bowl beneath, and then 1 to 2 tablespoons of kirsch are mixed in. This can then be spread across the Black Forest sponge as you assemble the cake. If you're aiming for a slightly boozier cake taste, use straight kirsch; if you prefer a sweeter touch, opt for cherry syrup.

Suppose you want to lean into the chocolatier side of this cake. In that case, Jamie Oliver has a tempting, less traditional approach that includes mixing kirsch into a chocolate ganache layer for the cake. This begins by heating heavy cream with 2 to 3 teaspoons of kirsch before whisking this into melted chocolate until smooth. This can then be spread as an extra layer between the chocolate sponge alongside a cherry pie filling and chantilly cream. Jamie Oliver also adds a sprinkle of popping candy into each layer, demonstrating how creative you can get with the seemingly traditional recipe. You could even go as far as to try a black-forest-themed waffle stack — an inventive way to use frozen waffles while mimicking the flavors of this luscious cake. 

If you struggle to find kirsch in a store, you can consider using rum as a replacement, as it'll pair wonderfully with the chocolate and cherries. Although for a Black Forest cake to be deemed authentic by German standards, it must contain kirschwasser. While recipe twists on the decadent Black Forest cake may reimagine some of the ingredients, it remains that adding kirsch is quintessential to achieving the unique flavor this dessert was designed to deliver.