Coffee macarons with espresso-chocolate ganache

It's notorious.  Macarons are finicky.  Just a couple of extra turns in the batter can make or break your macarons...though it does not have to be disastrous every time.  I've had the most success with macarons using Italian meringue (a meringue made with boiling sugar), with Pierre Hermé's recipe.  In fact, ever since adopting this recipe, every batch was a success!  Having said that, macarons are not something you can whip up on a whim, nor is it something to be made while multitasking.  If you are more of a free-spirited cook, stop reading this and jump to the page on ice creams, macarons will only set you up for countless disappointments.  Though if you are focused, well-planned and precise in following the recipe, macaron success shouldn't be far away!



To maximize your chances of success, here are a few key points:

Egg whites:  Egg whites need to be "liquified".  A few days in advance, preferably a week, separate the yolks from the whites.  Place the whites in a small bowl and cover with plastic wrap, then with the sharp point of a knife, pierce a few slits on the plastic wrap.  Store in the refrigerator until baking day.  This allows the whites to lose their elasticity.  Note that the weight of the whites will diminish as they sit in the refrigerator.

Almonds:  Ground or whole almonds can be used, though I prefer whole almonds and grind them in a food processor with the icing sugar.  I find that they don't go rancid as quickly and store-bought ground almonds are usually too coarse.

Kitchen scale:  Weigh everything! Even water!  This will ensure that all the proportions are accurate.

Oven temperature:  I always use the convection setting in my oven.   Be aware that oven temperatures vary from oven to oven.  The temperature control on the outside isn't always the actual temperature inside.  The best way to test is by using oven thermometer inside the oven.  If you find that your macarons are browning on top, or they are cracking, the oven is too hot.  If you find your macarons are sticking to the parchment after specified baking time, the oven is not hot enough.

Before putting the macarons in the oven:  Allow the shells to stand at room temperature until a skin forms on the surface.  The batter should not stick to your finger.  This could take anywhere from 30 minutes to 2 hours, depending on the humidity.  Be patient.  When the skins is formed, the macaron should turn from glossy to matte.

Coffee macarons with espresso-chocolate ganache

For the macaron shells:
150g ground almonds
150g icing sugar
55g 'liquefied' egg whites
3g instant espresso powder
+
150g caster sugar
35g mineral water
55g 'liquefied' egg whites

For garnish:
5g instant espresso powder
5g hot water

For the espresso-chocolate ganache: 
150g dark chocolate
150g whipping cream (35% fat)
5g instant espresso powder
30g unsalted butter, at room temperature

For the shells.
Sift together the icing sugar and ground almonds. 

Discard larger chunks that did not pass through the sieve.

Stir the espresso powder into the first portion of liquified egg whites and pour them over the mixture of icing sugar and ground almonds but do not stir.

Bring the water and sugar to boil at 118°C.  When the syrup reaches 115°C, simultaneously start whisking the second portion of liquified egg whites to soft peaks.  

  

                           

When the sugar reaches 118°C, pour it over the egg whites (while continuously beating on low speed).  Reduce the whisking speed to a medium speed and continue whisking the egg whites for about two minutes.

                          

Wait until the meringue has cooled down to 50°C, then tip it out of the mixing bowl and into the almond-icing sugar mixture.

Using a spatula, stir it into the mixture of icing sugar and ground almonds, folding in the batter and stirring outwards from the middle to the sides, rotating the bowl in your hands as you stir.

Continue stirring from the middle of the batter out to the sides of the bowl and rotating the bowl as your do.  

When the batter is starts to turn glossy and resemble a slightly runny cake batter, it is ready.

Spoon the batter into a piping bag fitted with a plain nozzle.  (I clip the end of my piping bag and place it over a pitcher for easier transfer.)

Pipe rounds of batter about 3.5 cm in diameter, spacing them 2 cm apart on baking trays lined with baking parchment.  

Rap the baking trays on the work surface covered with a kitchen cloth, this will help smooth out the tops and let out any air bubbles.  Leave the shells to stand for 30 minutes to 2 hours, depending on humidity, until they form a skin.  (When you touch the tops, the batter should not stick to your finger.)

                

Preheat the fan oven to 180°C then put the trays in the oven.  Bake for 12 minutes quickly opening and shutting the oven door twice during the cooking time. (Once at the 8 minute mark and once at the 10 minute mark.)  Out of the oven, slide the shells on to the work surface and let cool to room temperature.

 

For garnish:

Dissolve the instant espresso powder in hot water.  Dip a dry paint brush in the mixture and lightly brush the tops of macarons.

                 

For the espresso-chocolate ganache.  

Chop up the chocolate and melt it in a bowl over a pan of barely simmering water.  Combine cream and espresso powder and bring to a boil.  Pour it over the melted chocolate a third at a time.  Stir until smooth and glossy.  Stir in butter until smooth.

                   

Pour the ganache into a gratin dish and press clingfilm over the surface of the ganache.  Set aside in the fridge for the ganache to thicken.

For assembly.

Pair up macarons of similar sizes.

Spoon the ganache into a piping bag fitted with a plain nozzle.  Pipe a mound of ganache on to half the shells.  

Top with the remaining shells.

Store in the refrigerator in an airtight container for at least 24 hours.  Let stand at room temperature for 15 minutes before serving.

Macarons can be stored in refrigerator for up to 1 week.