How to Froth Milk

You don't need to be a barista to get that layer of velvety-smooth foam atop your cappuccino, says J. Kenji López-Alt, author of The Food Lab: Better Home Cooking Through Science, out this month.

Just vigorously shake a half cup of milk in a sealed microwave-safe, pint-size container until it thickens and creates a rich foam, and then microwave it for 15 to 20 seconds to stabilize it. For the best results, use 2 percent, 1 percent or skin milk; higher-fat milk doesn't work as well, and this is one case where nut or soy milk is no substitute for the real deal.