How does a 9 layer chocolate gateau grab you? Painfully by the balls should be the answer. Yes after months of mulling it over I've finally succumbed to the inevitable and decided to take on The BFG.
Made famous from Heston's 'In Search of Perfection' series in which Blumenthal visited The Black Forest in Germany to retrace the essence of the perfect Black Forest Gateau. He then returned with a big-ass 9 layer blockbuster of a dessert complete with Kirsch ice cream and multiple mousses.
The basic structure of the cake is as follows. At the base is a crispy almond praline, next a layer of apricot jam, then a chocolate ganache, aerated chocolate, cherries, chocolate sponge, white chocolate mousse and dark chocolate mousse encased in a flocage of chocolate and cacao finished with a cherry on top...phew! Maybe it should have been renamed BFD (Bound For Diabetes).
Another exciting addition to my kitchen is a gadget endorsed by Heston himself. Yes its a Sage Smart scoop Ice cream maker. Having made Mint Chocolate ice cream in it already I can confirm it is awesome.
Early stages of the aerated chocolate
Further equipment for aerated chocolate
What isn't awesome however is the aerated chocolate, the first layer of the 9 to be tackled. For this you need a whipped cream siphon, melted milk chocolate, a sous vide or vacuum space bag and a sous vide vacuum sealer or a vacuum cleaner. Fortunately I was going down the sous vide route so the Dyson stayed out of the kitchen on this occasion. The idea is to add groundnut oil to the melted chocolate, quickly place into the syphon that's been sitting in warm water (to keep the chocolate fluid). Hit with two charges and then give it a good shake before blasting it into a container. I placed cling film over the top with a hole before placing it into the sous-vide bag and putting it on full vacuum.
Word of warning here as my bag gave what can only be described as a bear hug to my plastic container causing some bending to occur so be careful that your vacuum doesn't go too far.
Taking the chocolate from the freezer after around an hour and a half with the container doing its best impression of a tangled wreck was nerve wracking, however once the bag was prised away from the tub and the cling film unwrapped there was a solid block of chocolate in there.......with bubbles!
Day two began with an early start to complete the biscuit base layer, consisting of toasted almonds, cherries and chocolate plus feuilletine (I used cornflakes) which are mixed together to create the starting point of the construction process. After smoothing the base out on a tray, followed by a quick roll over with a rolling pin to get the desired thickness, I placed it in the fridge to firm up.
Next the chocolate sponge....ever been tempted to go out and take advantage of half price on all kitchen bowls? Well if you're planning to take this on do go for it! Otherwise its endless washing up. I beat the egg yolks, sugar, cocoa powder, cornflour and plain flour together to make a thick batter. Contrary to the books instructions to whisk the whole eggs together, I decided to separate the whites from the yolks and whip to soft peaks, kind of a halfway point between Heston's flourless chocolate sponge and the BFG recipe from the book. This was in the hope of a lighter sponge.
15 minutes later the sponge was out of the oven and cooled, light as a feather. Next I began the stages for the Kirsch ice cream, making a simple custard recipe before cooling and chilling to mature the flavours.
While the custard was maturing I donned my builders hat and went for the first stage of the assembly job. Placing the cut out base at the bottom of the ring then smoothing a layer of apricot jam onto that. I deviated from the recipe slightly as there were slight gaps in my base to the side of the ring which worried me that when the Kirsch cream was poured in that I'd see it slowly oozing out of the bottom giving me the middle finger. So to counter this possibility I wedged the sponge layer on top and proceeded to soak this with the cherry syrup.
White chocolate mousse
Chocolate Kirsch ganache was the next hurdle, Heston bangs on about cubed butter at room temperature and heating the ganache to such-a-degree...yada yada.....JUST BREAK THE BLOODY CHOCOLATE UP AND STICK THE HOT LIQUID OVER IT!!! So I did....and it tasted awesome, especially with the addition of salt, really bringing out the flavour of the Kirsch and the chocolate.
For the white chocolate mousse (bored yet?) its another masterclass in custard making before adding melted white chocolate, gelatine and folding in whipped cream flavoured with Kirsch when cool. One thing the book says is to heat the custard, add in the melted white chocolate, gelatine and fold in the cream, now surely when you fold cold cream into hot chocolate custard the result will be chocolate soup? Something to watch out for.
First stages of the chocolate mousse
After sitting the mousse in the fridge and piping ganache, adding cherries and the aerated chocolate to the layers already in place, I piped the mousse around the top layer after letting it rest for 30mins in the fridge.
Last in the first stage of construction is a dark chocolate mousse, made in the same way as the white chocolate mousse, once the layers are set in the fridge, add the chocolate mousse and place in the freezer for 3-4 hours to firm up.
Ready for the freezer
Unmoulding the gateau was a pain in the arse as the mousse had decided to weld itself solid to the side of the ring so much so that not even the intense heat of a blowtorch could prise it away. In the end I used a cocktail stick to provide damage limitation and take the ring off. Seeing my handy work for the first time was satisfying, each layer defined. Beautiful.
I covered the cakes with cocoa powder instead of the expensive option of chocolate and cacao in a paint spray gun, granted it looks better but is it worth the expense? Not for me.
The ice cream was left to churn away and all was set to plate up.
Beginning with a swipe of cherry puree rounded off with some reserved gateau base that I'd crumbled to make a garnish all that was left was to attempt a rocher of kirsch ice cream and place the gateau and cherry on the plate. I had planned to pipe cherry puree down the side of the cake but the puree was too fluid and wouldn't have worked.
The final plate
So two days, numerous processes and many ingredients later....how did it turn out? Appearance wise I was happy, although the struggle to get the ring off the cake had left a few dents, the cocoa powder was thick in places but counter-acted the sweetness of the layers inside. The ice cream was incredibly soft when the time came to rocher so it wasn't the greatest effort....
Inside the Gateau
But wow, what a flavour combination, the ice cream is epic, clean and fresh laced with the alcoholic kick from the Kirsch, the layers all work in symphony. When making the layers I became increasingly worried that the whole thing was going to be too rich and sickly but I need not had worried. It was well worth the work.
Would I make it again? Probably not to the extent of the recipe, maybe the crispy base, some mousses in the fashion of panna cotta's could be an idea to try but I'm glad to say that I've finally conquered the BFG.