There are few food products that can, from the same recipe, produce something that is light and crunchy or smooth and creamy. Magical meringue spans this texture spectrum like no other food.
Much more than just a pie topping, meringue is the basis of many great desserts like vacherin (crispy shells that hold myriad fillings), cookies including the classic French macaroon, chiboust (meringue folded into flavored pastry cream), dacquoise (meringue cake layers with nuts) and pavlova. Meringues also are used to make butter cream icings for cake decorating.
I used to think I didn't like meringue. My experience was limited to soggy, rubbery concoctions that adorned equally underwhelming pie fillings in dingy diners. Once I discovered a meringue that wasn't overbeaten and overbaked, it was a revelation.
Meringues use the foaming properties of egg whites to create a light, airy product. All meringues contain egg whites and sugar and most also include cream of tartar, beaten together until a firm, stable foam is produced.
When, and in what form, the sugar is added is what makes each one different. In another article, I'll discuss the pros and cons of Swiss and Italian meringues. (If you are interested in the science behind meringue, I recommend reading Shirley Corriher's "Cookwise" or Harold McGee's "On Cooking.")
To properly beat egg whites, the eggs should be clear of yolk and the bowl should be clean. Contrary to the horror stories I have read that even a trace of yolk or fat will ruin the foam, I have made a decent meringue with a small amount of yolk that I couldn't fully remove. If a bit of yolk gets into the whites, don't panic. Get as much of it out as you can, and proceed with the recipe.
(The way many cookbook authors alarm readers with the dire consequences that will result if someone deviates an iota from their recipe, it's a wonder anyone tries making them at all.) Console yourself with the thought that even if what you make drifts off the course of perfection, it's much better than what comes out of a box, can or dingy diner.
Unlike cream, in which everything should be chilled to get the best volume, egg whites whip best at room temperature. Fisticuffs may arise between professional bakers as they argue about when to add the sugar into the egg whites for a classic meringue. Some say add sugar only after the whites have reached soft peaks and then only a bit at a time; some add a little gradually throughout the process; and some add most or all of it in the beginning or the end. I generally add the sugar gradually once the egg whites look like a dense foam but before soft peaks form.
The most common mistake people make is that they overbeat the egg whites, which results in a curdled, rubbery texture. It is best to err on the side of underbeating the whites. Remember that the whites should still be glossy at the end. If they start to lose their sheen while beating, stop!
The best tool for beating egg whites is a stand mixer with a whisk attachment. A hand mixer will work but it will take a bit longer to achieve the same volume. A strong forearm and whisk are also acceptable - just don't ask me to do it. Once the meringue is made, it needs to be used quickly because it will deflate over time.
A word about food safety. Meringue is not free from risk as a raw egg product unless baked or cooked to an internal temperature of 160 degrees, which for a pie filling means it will be overcooked and will weep. Crisp meringue cookies or shells and poached meringues are generally safe, however.
The only way to be 100 percent safe is to use powdered egg whites, which can be expensive although they work fine. I throw caution to the wind and leave my whites out overnight to come to room temperature. I also eat raw cookie dough and brownie batter with abandon. You must assess your own risk tolerance.
Using the accompanying meringue recipe, I have made both crisp shells and creamy poached meringues. Although poached meringues (also known as oeufs à la neige or "snow eggs") have been around for some time, they fell out of fashion long ago. Typically served with crème anglaise, I usually serve "snow eggs" with a sauce made from peaches and yogurt spiked with mint, a recipe I adapted from one in Jacques Pepin's "Sweet Simplicity."
I puree canned peaches in light syrup with plain yogurt, a dash or two of orange liqueur and a few mint leaves in a blender and serve the meringues on top with a drizzle of raspberry or blackberry sauce. It's an elegant and refreshingly different dessert.