When I receive a request to make something that I haven't made for awhile, it prompts me to research recipes and re-live those practical kitchen days from pastry school. So, since I had an order for this classic Viennese cake, I made a Sacher torte.
The story goes that this cake was created in 1832 by a 16 year old apprentice chef, Franz Sacher, for Prince Wenzel von Metternich in Vienna. The Sacher torte has since become a fixture at the Hotel Sacher Vienna, where they say the original recipe remains a secret.
Even so, there are numerous recipes out there, each with its own variables. All of them call for bittersweet chocolate, eggs, sugar, flour, butter, a little salt (for mounting the egg whites) and usually some vanilla extract for a standard 9" cake.
Here are the steps and some of the recipe differences I encountered as I made my way to a Sacher torte!
Prep a 9" springform pan by buttering the bottom, covering it with a round of parchment and buttering that. Some folks also flour the parchment - I chose to dust it with cocoa powder.
The chocolate is melted over a bain marie and allowed to cool to tepid before it is added a bit later. I'm using a mixture of Valrhona 64% and Trader Joe's "dark" and "72% dark" chocolates. Chocolate quantities vary from recipe to recipe, anywhere from 113-227 gms (4-8 ounces). I used 142 gm.
The butter can be melted along with the chocolate, but most recipes seem to prefer creaming it with a portion of the sugar. That's the method I used. Butter quantities ranged from 85-250 gm (3-9 ounces) in the recipes I reviewed. I used 126 gm.
Above: butter and confectioners sugar ready to go
My review also revealed sugar amounts from 113-225 gm (1/2 to 1 cup), some recipes using a combination of confectioners sugar (for the creaming step) and granulated sugar (for beating with the egg whites.) As you see above I used confectioner's sugar (50 gm) for the creaming step.
This cake is considered a biscuit which means the eggs are separated, and the yolks and whites are beaten separately before blending together. Egg quantities varied from 4 to 8 (most commonly 6) in my review.
Some recipes call for whisking the yolks with a portion of the sugar to the ribbon stage, and then adding the melted chocolate and butter.
In the method I used here the 6 yolks and a teaspoon of vanilla are blended into the creamed butter and sugar mixture, and then the cooled, melted chocolate is added.
Above: adding the chocolate - wheeeee!
Next sift the flour (130 gm) over the chocolate mixture and gently fold it in.
I found the amount of flour called for was most commonly one cup. However, some recipes use cake flour or cornstarch in place of all purpose, and some use almond flour as a portion of the total flour.
Also there were variations in the flour adding step - some did it before and some after the egg whites.
Now it's time to whisk the egg whites to soft peaks. Egg whites mount better at room temperature, so I usually separate my eggs early in my mise en place and let the whites start to warm up. Alternatively you can place your bowl of whites in some warm water to speed up the process.
Above: whites, salt and sugar ready to go
I like to start my mixer on low speed and let the whites and salt (1/4 teaspoon) start to foam a bit. Then I slowly add my sugar (112 gm) while the mixer is running, then increase to high to finish them off to soft peaks.
Now fold about 1/3 of the whites into the chocolate mixture to lighten it, then gently blend in the remaining whites just until a few streaks remain.
Above: whites partially blended in
Place the batter in the prepared pan.
Bake at 350ºF for approximately 35-40 minutes, or until a tester comes out clean.
Let it cool a bit, unmold and finish cooling.
Traditionally the Sacher torte is layered with an apricot jam filling. Most recipes called for slicing the cake into two layers, but a few into three. My cake was destined for two.
Filing methods include: simply spreading apricot jam between the layers; warming and straining the apricot jam before spreading to remove the chunks (some preferred that for mouth feel); puréeing the jam to de-chunk it; taking a small amount of jam, diluting it with water and puréeing it to use as a glaze on each layer in addition to spreading jam between the layers. Anyway, you get the idea - to each his/her own!
Above: layered with apricot jam and glazed with apricot glaze
All recipes agreed that once the cake is "jammed" (thanks Parks and Rec!), give it a 30 minute chill before the final chocolate glazing.
The chocolate glaze recipes varied from the "add boiling water to the chocolate" method to a more traditional chocolate ganache type of glaze. The one I chose was a 3-part chocolate (170 gm) to 1-part cream (56 gm) ganache with a bit of butter (28 gm) added. It had a nice sheen.
Now I'll admit I was lazy here and did not follow the tradition of writing the word "Sacher" on the top of the cake. Instead I made my go-to simple swirl design. Thank goodness for my small offset spatula!
So choose your recipe and go for it!
If I ever get to Vienna and have a chance to try the real thing, I'll let you know!!