MARTHA'S MASTERCLASS

Since reaching the quarterfinals in 2014 Martha Collison has written two cookbooks and a weekly column in Waitrose Weekend. She’s sharing her tips every week during The Great British Bake Off 2018

Biscuits

Making magic meringue for pavlova and roulades

A truly impressive week all-round ended rather joyfully, with no one going home after the bakers had battled it out creating meringue roulades, chocolate spheres and - to my horror - blancmange. I’m not sure this gelatine-heavy, disturbingly pink milky jelly is ready for a renaissance just yet. I’m focusing on something sweeter instead: the magic of meringue.

The basic recipe for meringue contains just two ingredients: egg white and caster sugar. It is hard to believe they come together and transform into something so dramatically different from their starting materials.

Egg white is a mixture of proteins and water molecules. When whisked, the proteins unfold and bubbly pockets of air are forced into the structure. The unfolded proteins bond, creating a ‘scaffolding’ that holds onto the air, accounting for the voluminous white foam. For a meringue, you need to whisk the egg whites into stiff peaks that don’t move when you tip the bowl upside down. If you haven’t whisked in enough air, you will have trouble when you add the sugar.

The sugar is added to the mixture once air has been locked in. Sugar granules dissolve in the water in the egg whites and allow even more air to be incorporated. Heating the sugar before adding it to the egg whites helps it to dissolve more quickly, and help prevent it from cracking.

The final stage is the baking. Heating the meringue mixture causes the water to evaporate, the air pockets to expand and the protein structure to set. To make a pavlova, a low oven temperature and long bake produces the crisp and chewy finish. Our bakers were aiming to roll their meringues into a roulade and retain a marshmallow-y texture in the middle, so a higher temperature and quicker bake is perfect.

Biscuits

Making chocolate collars - here's how to temper chocolate

During Cake Week the bakers experienced what must have been the start of this summer’s glorious heat wave. Lovely for enjoying cool drinks outside in the sunshine, not so ideal for making intricate chocolate collars on TV. Still, the contestants handled the heat admirably, as it can be roasting in that tent.

Tempering was mentioned a lot this week, as the contestants had to temper the chocolate to form their collars. It sounds scary, but it is simply the process of heating and cooling chocolate to specific temperatures. Bars of chocolate are already ‘in temper’, meaning they are shiny and have a snap. When you melt chocolate and allow it to cool without tempering it, the cocoa butter will solidify and it will be dull and crumbly. Tempering controls the way the cocoa butter crystals solidify. There are several ways, but ‘seeding’ is the one I like best because the only specialist equipment required is a sugar thermometer. Here’s how to do it:


1) Chop the chocolate you need into small, evenly sized pieces. Remove a third of the chocolate and set aside, melting the remainder until it reaches 45°C on a sugar thermometer.


2) Stir in the chocolate you set aside until it has melted into the mixture. Adding solid tempered chocolate into melted chocolate encourages the correct fat structure to form.


3) When there are no lumps in the chocolate, check the temperature. It should register 32°C on the thermometer and is now ready to use. Milk chocolate should be 29°C and white chocolate should be 30°C. Use the chocolate to coat truffles, make chocolate shapes or simply pipe onto the top of cakes.

Biscuits

Wagon wheels: how to get the jam right

Bake Off is back and the baking spirit has been reawakened across the UK. Episode one was a brilliant start to the new series, and beginning with Biscuit Week instead of the usual Cake Week was a nice change and really tested the 12 bakers’ skills.

I remember Biscuit Week being particularly challenging, as a lot of the bakes are so thin that a matter of minutes can mean the difference between under-baked and burnt.

You have to be completely switched on and make sure your oven temperature is spot-on to ensure a crisp and even bake.

Temperature was a running theme this week, with the bakers attempting components like jam and marshmallow for the technical challenge of wagon wheels that rely entirely on accurate temperatures.

A sugar thermometer is a really useful piece of kit to help get this right, as it is a part of baking that simply cannot be determined by eye. Jam needs to reach a temperature of 103-106°C in order to set. Too high and the pectin (a fibre found within fruits that gels in the presence of acid and sugar at the correct temperature) will become less effective, and too low it will not form a gel at all. When you are checking for the right temperature in your boiling jam, be sure to spot test a few areas of the mixture so you can be confident that the whole pan has reached the correct temperature.