"If your pan does not have a heavy bottom or your stove does not operate properly at a low setting, a heat diffuser for stove top use is necessary to spread the heat evenly across the bottom of your pan," Mr. Kornbleuth explained in an email.
Taylor from The Brooklyn Kitchen told us that diffusers can "help turn just any pan into a heavy-bottomed pan or dutch oven and allow you to use glass or terra cotta on the stovetop."
These diffusers work safely with electric and gas stoves. They can be used to prevent hot spots in a pan. Cooks find them useful when making delicate sauces and melting chocolate.
The Panhandler said heat diffusers have other benefits: they help to keep pots from discoloring from high heat, can be helpful for heat balancing small pots, like butter warmers and espresso makers. "Large diffusers prevent handles and side grips from overheating," Mr. Kornbleuth said.
Wait until the diffuser has cooled until you remove it from the burner. "A pan grabber or pair of pliers can also be helpful to remove the diffuser from the stove top," Mr. Kornbleuth said.
Keep in mind that the oven is likely the best source for the even, low heat a braise depends on. This is an alternate solution for those who prefer to braise stovetop becasue they don't have an oven in their apartment and those who avoid the oven because they find it heats up their small space too much.
Broadway Panhandler sells several types of heat diffusers (dark anodized aluminum discs, enamel cast iron and perforated steel discs) for $3.95 to $24.95. The Brooklyn Kitchen has a 6 1/2" iron diffuser with a smooth enamel top and removable handle for $19.99.