I am practising decorating chocolate cakes for my friend’s birthday, and decided to try out 2 recipes I been looking at for a while, Rose Berenbaum’s moist chocolate genoise and chocolate cream and chocolate glaze from Thomas Keller’s Bouchon Bakery.
The recipe I ended up using was adapted from the 2 books above:
Makes one 8″ cake
For chocolate genoise
113 grams bittersweet chocolate
118 grams boiling water
4 large eggs
100 grams sugar
75 grams sifted cake flour
For chocolate cream
333 grams heavy cream
233 grams bittersweet chocolate
3 egg yolks
83 grams granulated sugar
For chocolate glaze
7 grams gelatine powder
150 grams heavy cream
225 grams granulated sugar
180 grams water
75 grams unsweetened cocoa powder, sifted
1) For the genoise, preheat oven to 175C.
2) In a heavy saucepan bring the chlorate and water to a boil over low heat, stirring constantly. Simmer, stirring, for 5 minutes or until the chocolate thickens to a pudding-like consistency. (It will fall from the spoon and pool slightly before disappearing.) Cool completely.
3) In a large mixing bowl, beat the eggs and sugar with the whisk beater on high speed for 5 minutes or until triple in volume.
4) Sift ½ the flour over the egg mixture and fold it in gently but rapidly with a slotted skimmer or large rubber spatula until some of the flour has disappeared. Repeat with the remaining flour until all flour has disappeared. Fold in the chocolate mixture until incorporated.
5) Pour immediately into the prepared pan and bake 30 to 35 minutes or until a tester inserted in the centres enters as easily as it does when inserted closer to the sides.
6) For the chocolate cream, whip the cream to soft peaks; refrigerate.
7) Melt the chocolate in the top of a double boiler. Transfer the chocolate to a large bowl and let cool to room temperature.
8) Meanwhile, whisk the eggs, egg yolks, and sugar in the top of the double boiler over simmering water. Initially the eggs will increase in volume and foam, but after 5 to 7 minutes, the foam will begin to subside and the eggs will thicken. Watch the temperature closely, as the eggs will begin to set if they get too hot; when the temperature reaches 83C, immediately transfer them to the bowl of a stand mixer fitter with the whisk attachment and whip on medium-high speed for about 7 minutes, until the mixture thickens. When the whisk is lifted, the mixture should form a slowly dissolving ribbon.
9) Whisk one-third of the whipped cream into the chocolate to combine. Fold in the egg mixture, then fold in the remaining whipped cream. Transfer the chocolate cream to the pastry bag.
10) For the chocolate glaze, place the gelatine in a bowl of ice water to soften.
11) Place the cream, sugar and water in a large saucepan and bring to a boil. Whisk in the cocoa powder, reduce the heat to keep the mixture at a gentle boil, and cook for about 15 minutes, until the mixture has reduced by about one-third. Test by spooning a small amount onto a plate: run your finger through it – if it runs together, continue to reduce it until your finger leaves a track. Once it has reached the desired consistency, remove the mixture from the heat. Wring the excess water from the gelatine and whisk it into the cocoa mixture.
12) To assemble, since the genoise horizontally in half. Put one half on the cake board, and pile on a little more than one third of the chocolate cream. Top that with the other half of the genoise, and pile it with another one third of the chocolate cream. Then, coat the sides with the remaining chocolate cream and freeze. When chocolate cream has set, smooth the sides and top and return to the freezer, preferably overnight. To glade the cake, set it on a cooling rack, and pour glaze over a sift onto the cool cake. Let the glaze run down the sides and collect in a baking sheet underneath. Let glaze set in a refrigerator (freezer works too).
I did not fold the flour into the genoise well enough and ended with some white patches, but I thought the cake goes quite well with the chocolate cream. Also, I used a cake ring for this attempt. The next time I shall do it free-hand as described above. And most importantly, the chocolate cream must be SMOOTH in order to achieve the shiny surface from the glaze.