William Curley has five times won the title of “Britain’s Best Chocolatier” and I recently attended a course at his Belgravia shop to learn the secrets of making chocolate truffles. The course was conducted by his head chocolatier, Alistair Birt, and along with 8 other participants we made their House Dark Truffle using Amedei Chocolate. This is the base recipe:
To make approx 30 truffles
145g whipping cream
160g 70% grated chocolate
25g unsalted butter (at room temperature)
250g tempered chocolate
150g cocoa powder
The first step is to combine the cream and chocolate to make a ganache. The cream is heated to boiling point and then poured over the grated chocolate, mixing gradually with a spatula until it is smooth and glossy. Then the butter is stirred in – this is an optional ingredient but used at Curley’s because they believe it improves the mouth feel. The ganache would then ideally be left to set at room temperature, but because of the time constraints of the course we refrigerated it.
Once the ganache is firm, spoon it into a piping bag and pipe bulbs onto a tray lined with silicone paper and leave to set in a cool place. If you don’t want to pipe, you can just spoon teaspoonfuls of the mixture onto the sheet – they will be more roughly shaped, but this doesn’t really matter as chocolate truffles should resemble the truffles that come out of the ground in appearance. An alternative is to pipe the mixture into a continuous “sausage”, which you then cut to the required lengths once set.
The next step, coating the ganache in tempered chocolate, was one of the key things I had come on the course to learn, having previously missed out this stage when I made them at home. Alistair agreed that tempering is what bothers most amateurs, but that at Curley’s, where of course they are tempering all the time for their other chocolate creations; it is included with the truffles to create a different texture, a crisp outer coating around the smooth ganache. Having now made both versions I think I will be reverting to just coating the firm ganache with cocoa powder. The tempering is not very difficult, but it does require a decent quantity of chocolate to work with, and results in some waste (how much depending on your skill level). As you will see from the ingredients above, it uses more chocolate than the ganache itself and thus contributes significantly to the cost. In addition, I’m not sure that I actually prefer the dual textures. For me, part of the pleasure of a truffle is to just let it melt in the mouth, savouring the flavour as you do so, whilst the crisp coating left me feeling the need to bite. However, if you do want a contrasting texture, you could just roll the ganache in chopped nuts or even grated chocolate.
Here is what I learnt about tempering:
Tempering brings the cocoa butter to the correct crystalline state so that it melds smoothly with the cocoa solids. The chocolate will be sold already tempered, but when you melt it to alter the shape, you will have disturbed this balance. Most critically in chocolate making, the mixture will contract by about 2% when tempered, so that it naturally contracts from the mould –if you have ever tried making Easter eggs or filling any other chocolate mould you will know the frustration of trying to turn out a chocolate that has not been correctly tempered. The surface will also be clear and bright – we have probably all purchased chocolate that has been stored in too hot a shop and seen a bloom on the surface and found the chocolate melt immediately you touch it. Whilst this can still be eaten perfectly safely, it does actually affect the taste experience as chocolate should melt at body temperature, i.e. within the mouth.
Having melted the chocolate (at home usually done over a saucepan of simmering water, but be really careful not to allow any water, or steam, into the chocolate) – or in a microwave, it will be at around 40˚C and needs to be cooled to between 30˚ and 32.9˚C to remix the cocoa butter and solids. The traditional way to do this was to pour the chocolate onto a marble worktop and move it around until it had cooled, but Alistair feels this is unnecessary and showy, preferring to melt just half the chocolate and then add the remaining half, grated, to reduce the overall temperature. He judges the temperature by eye rather than using a probe, the critical test being the speed at which the chocolate sets when spread thinly on paper. This is a little like testing for a set in jam. The photograph below shows four tests in chronological time order from left to right. The tests were done at about 5 minute intervals and in the first two the chocolate still isn’t set – if it doesn’t set within 5 minutes it is not yet cool enough.
The next job was to coat the truffles in the tempered chocolate, and then immediately into cocoa powder. We donned disposable latex gloves and worked in pairs, one person allocated to each task. Even then we found that the chocolate quickly began to set and we had to be given freshly tempered chocolate for coating. It is possible to re-heat and temper the set chocolate – providing it has not been contaminated in any way. Alistair said that at home he would use a hairdryer to bring the chocolate gently back to tempering point, but consider the difficulties of working solo.
Finally excess cocoa powder was removed by sieving.
Infusion – this is the main method used for flavouring the truffles. The cream is brought up to simmering point and then the chosen flavour infused for several hours (at Curley’s overnight in the fridge). Examples of flavours that are incorporated in this way include herbs, spices, coffee and citrus zest.
Alcohol – a proportion of the cream can be replaced with alcohol. For liqueurs and spirits the proportion is one quarter, for Champagne it would be one third (added after the cream has been heated).