Refresh Homemade Sourdough Bread With A Common Kitchen Appliance

Thanks to its bevy of nutrients, fibers, and proteins, sourdough bread is more filling than regular bread, which potentially makes it a healthier option than other loaves — not to mention the fact that some with gluten sensitivities can also eat sourdough. However, its robustness also means that you're more likely to have a leftover partial loaf. As hearty as it is when fresh, stale sourdough bread can quickly become too tough and chewy to enjoy. This is especially true if the loaf has been frozen for long-term storage.

The good news is that you will never have to throw away a sourdough loaf unless it's spoiled. Even if it gets tough, you can repurpose it into breadcrumbs or even make hearty Italian ribollita soup that makes stale bread delicious. However, there's nothing quite like being able to refresh your loaf so you can enjoy its crackling crust and soft crumb even after it's spent time in the fridge or freezer. This is also useful for home bakers as you try out multiple loaves. If you're just starting out with homemade sourdough, practice is essential, but you can significantly cut down on trial and error by getting helpful tips from an expert. We spoke extensively with Nathan Myhrvold, founder of Modernist Cuisine and co-author of "Modernist Bread at Home" about all things sourdough, including tips for making and refreshing loaves at home. According to him, "You can easily and quickly refresh bread using a conventional oven, toaster oven, or microwave."

For best results with either an oven or microwave, Myhrvold maintains that you will need a food thermometer with a probe (many like this highly-rated Alpha Grillers variety). You'll use it to check whether the loaf's interior has reached the required temperature. The goal during this reheating process is to redistribute moisture away from the crust to make it crispy again while retaining the moisture inside the bread. Note that these steps can also be used for individual sourdough slices.

Myhrvold offered us step-by-step instructions on how to refresh a loaf in the oven: "start by preheating the oven to 175˚C / 350˚F. Next, wrap each loaf, roll, or slice individually with aluminum foil. For loaves or rolls, insert the probe of an oven-safe thermometer into the thickest piece so that the probe tip rests at the deepest part of the crumb. Heat the bread in the oven until the core temperature reaches 77° C / 170° F." 

While you should target the same internal temperature even when reheating the loaf in the microwave, the process is slightly different. The bread must be heated uncovered, for one. Myhrvold recommends microwaving a cup of water alongside the bread to balance the moisture. Use the high heat setting on the microwave and heat in 30-second intervals until the required internal temperature is reached.

If you plan on toasting the sourdough, Myhrvold says that you don't even need to bother with refreshing. Instead, toast frozen slices directly — great news considering sourdough is one of the best breads to make a grilled cheese.