Creme brulee’s signature is that crisp, caramelized crust that sits atop the delicate custard. You make it by sprinkling on a layer of sugar, then caramelizing it with the flame of a kitchen torch. If you’ve made creme brulee, before you may have run into a common problem with this straightforward-sounding step. Sugar that is in too thin of a layer won’t caramelize into a crisp crust. Sugar that is too coarse will not caramelize easily, leaving you with uncooked sugar at the top of your brulee or with a slightly melting custard beneath a topping that needed too long under the torch.
The best sugar for topping off a creme brulee is superfine sugar. Its tiny crystals caramelize quickly and easily. You can find it at most grocery stores, but if you can’t, regular sugar is your next best bet because it is also relatively fine in texture. Brown sugar is too moist and clumpy and raw sugars tend to be far too coarse. If you have a large-grained sugar that you would like to use, give it a whizz in the food processor to break down some of those crystals and make it more like regular or superfine sugar, then use it to top off your brulee.