Don't Microwave Bread Without This One Extra Item

If you've ever brought home a few loaves of bread but didn't mange to eat them all while they were fresh, it can be difficult to reheat and restore them to their former glory. Most people would think twice before putting bread in the microwave, but one expert disagrees. We spoke with Nathan Myhrvold, founder of Modernist Cuisine and co-author of "Modernist Bread at Home," whose scientific and researched-based approaches to cooking and baking help shed light on the topic. 

Although using a microwave isn't the most ideal way to reheat bread, sometimes it's necessary, and can even be a great tool to use. "In our experiments," says Myhrvold, "we found that microwaving performs surprisingly well for smaller loaves of bread." When you do need to refresh more miniscule loaves, Myhrvold recommends "placing a small glass of water in the microwave along with your bread." The water will lend a bit of moisture to the air, preventing the loaf from getting too hard and dry. 

"Run the microwave in bursts of 30 to 45 seconds," Myhrvold instructs us, "and check the bread's internal temperature each time until the thermometer reads 170 degrees Fahrenheit." The best and easiest tool to use for the task is a digital instant-read thermometer, which you'll find a variety of uses for in your kitchen. 

Because every appliance is different and they all can vary in power, it's difficult for Nathan Myhrvold to provide an exact time frame for heating. "A small bun or roll might take 45 seconds," he says, adding that larger loaves of bread will need a bit more time than that. However, Myhrvold advises against trying to microwave loaves of bread larger than 18 ounces (or 500 grams). "Large loaves are hard to warm uniformly due to the hot and cold spots in the chamber of the microwave," he explains. Additionally, Myhrvold recommends "eating microwaved bread soon after it has been reheated."

When asked about his preferred technique for warming bread, Myhrvold doesn't have any fancy tricks up his sleeve. "My favorite method for refreshing bread is incredibly straightforward: Simply wrap it with aluminum foil and warm it in a 350 degree Fahrenheit oven or toaster oven," he shares. Myhrvold aims for the same internal temperature of 170 degrees Fahrenheit and, once the inside of the loaf is hot, he recommends that you "open up the foil to crisp the crust in the oven for an additional 5 to 10 minutes." As he explains, "The goal is to get every part of the crumb hot enough to undo the chemical changes that cause staling — but not so hot that the crust darkens." Myhrvold tells us that this technique also works for individually wrapped slices of bread, but that you should check the temperature every minute or so to not overheat the slices.