The combination of sweet almond macarons and musky earthy mushroom-truffle ganache is a surprising one which is fast becoming a modern classic. Inspired by one of Pierre Hermé's signature flavours, this recipe uses truffle oil and cep powder to lend the earthy, umami notes to the ganache. The flavours should be subtle but just present enough to make an impression. It's best to err on the side of caution when adding the truffle oil and cep powder to the ganache and taste as you go.
Hermé's macarons use white chocolate for the ganache but we've used a mixture of white and dark chocolate just to take the edge off the sweetness. The richness of this chocolate also works perfectly with the complex flavours of black truffle.
We’ve used a small amount of titanium dioxide in this recipe – titanium dioxide whitens the macaron mixture giving the shells a bright white finish. It is a professional pâtisserie ingredient, and is very highly concentrated so even a tiny amount will have a big effect. Therefore use with caution, and take care to measure it out using high accuracy weighing scales. It is better to use too little than too much.
For top tips on macaron making see our article 5 Common Problems When Making French Macarons.
For the white macaron shells Serves: 36
For the truffle ganache
To make the white macaron shells
- Begin by weighing out the icing sugar and ground almonds in a bowl.
- Transfer to a food processor and whizz for a few seconds until fine. (Be careful not to over mix or the almonds will begin to release their natural oils and cause the finished macaron shells to look 'blotchy'.)
- In a large bowl pour 110g egg white over the almond/icing sugar and leave it to sit on the surface without stirring whilst you prepare the Italian meringue.
- Line 4 large baking trays with parchment paper.
- Pour the second half of the egg whites (110g) into a stand mixer with a whisk attachment.
- Heat the caster sugar and 75g water in a pan. Monitor the temperature with a cooking thermometer and when it reaches 117°C start to beat the egg whites on full speed until they just reach the soft peak stage.
- When the sugar syrup reaches 121°C pour slowly over the egg whites whilst they are whisking.
- Whisk for 3 minutes on high speed. Reduce the speed to medium and whisk for a further 2 minutes. Then whisk on a slow speed until the Italian meringue has cooled to 50°C.
- Use a maryse spatula to fold the Italian meringue into the almond mixture. Be fairly vigorous at first.
- When the mixture is homogenous, add the titanium dioxide dissolved in the water.
- Keep folding the mixture gently until it begins to relax and starts to turn glossy at the edges. Another way to test the consistency is to dab the mixture with the end of the spatula, the imprint should fade in around 20 seconds.
- Place a round 10mm nozzle in a piping bag and fill with the macaron mixture. Pipe rounds with a 3.5cm diameter spaced 2cm apart.
- Leave the macarons to dry out overnight or place in a dehydrator on the lowest setting for 20 minutes. A dry skin should form on the surface of the macarons so you can run your fingers over them without them becoming sticky.
- Pre-heat the oven to 160°C (fan oven) - the ideal cooking temperature can range from 140°C - 170°C depending on the oven.
- Cook the macarons for 12 minutes. Open the door after 8 minutes to release the steam and again after 10 minutes.
- Transfer to a cooling rack. Wait for the macarons to cool before peeling them off the parchment paper.
To make the truffle ganache
- Bring the cream to the boil in a pan together with the cep powder.
- Pour over the chocolate. Leave for 30 seconds then stir to form a smooth, glossy ganache. If there are any chocolate lumps left heat the bowl over a pan of hot water until they melt.
- Stir in the truffle oil.
- Refrigerate for 5-10 minutes until just viscous enough to pipe.
- Place a 10mm piping nozzle in a piping bag and fill with the truffle ganache. Pipe rounds to within 3mm of the edge on half of the macarons. Top with the other half and refrigerate for 24 hours before consuming.