Have you ever wondered how runny egg whites turn to foam when beaten? Well, when you whisk them, the egg white liquid is drawn through itself, making the protein molecules separate and ‘disorientate’. The other thing which makes proteins unfold is that the beating mixes air in. This disturbing of the natural state of the proteins is called ‘denaturation’. The proteins rush to be together where the water and air meet then clump with other unfolded proteins. This creates foam and the air is held in. Miraculously, this beating process expands the egg whites to up to eight times their original volume.
However, lots can go wrong when you’re trying to beat an egg white till stiff and keep it that way. The trick is to stabilise it and one way is to use a copper or silver mixing bowl. The metal in the bowl helps to bind the proteins more tightly. The bowl must be scrupulously clean and the best way to ensure this is to rub a cut lemon around it. You can also use glass and ceramic bowls of course and add a little salt, lemon juice or cream of tartar because that acid changes the pH of the egg whites, increasing the hydrogen and stabilising the proteins. Any suggestion of oil or fat will prevent theproteins from denaturing which is why you can’t let even the tiniest smear of egg yoke get in.
The beater you use – which can be two forks held back to back, a birch whisk, balloon whisk, electric hand-beater or food processor – must be very clean. I mean, you can see how easy it would be to have a mental breakdown over this, never mind that you’ll never get a husband out of it. People talk about the stress of driving in downtown traffic – they’ve obviously never tried to beat till stiff.
When I was a chef in Paris I was taught how to beat egg whites with a large, stainless steel balloon whisk in a figure of eight motion. This is a very efficient way of beating and with practice you can get very fast with it and turn it into a party trick. The thing with cooking techniques is you have to prove you are at the top of your game – it’s relentless – professional kitchens are armageddons of competitiveness... think Masterchef. Not many cooks can pull the figure of eight coup off in company so by performing it you are way ahead of any pretenders to the throne of exhibitionism.
All this is to tell you that winter is the time to make the most famous stiff egg white dish of all –meringue, that ecstatic method of beating sugar held together by clouds of whipped albumen. Meringue needs cold and dry weather, not the destabilising heat and humidity of summer. French meringue is the easiest and most delicate method where you just beat sugar and egg white slowly till stiff then cook immediately in a very low oven. Meringues can be flavoured with caraway seeds, lime zest, chopped walnuts, ground almonds and can be dusted with cocoa. You are never too old, too fat OR too full to eat another meringue.