How we tested
Leave a pan of milk or cream on the stove long enough, and it’s sure to foam up and boil over. A lid won’t stop overflows, but boilover devices purportedly prevent messes in a few different ways. Large silicone lids physically stop or slow boiling milk from escaping the pot. Small disks made of glass, ceramic, or stainless steel placed in the pot change the heat distribution of the contents or simply rattle to alert the cook. The disks were ineffective; glass and ceramic disks did audibly clatter as the milk began to boil, while a stainless steel disk barely made a sound, but none prevented a boilover. The only tool that prevented the milk from escaping the pot was our winner. Its bowl-shaped silicone lid (which doubles as a microwave splatter guard) has six central flaps that open just enough to let milk foam flow over its surface, where it is contained by curved edges. The tool works, but unless you also need a splatter guard, we recommend using our equally effective method: Simply heat the milk in a pot much larger than necessary.