Simmering is a cooking technique that involves cooking food in liquid at a low temperature, usually between 160-180 degrees Fahrenheit. The term 'SIMMER' is often used interchangeably with the term 'STEWED, ' which is another cooking technique that involves cooking food in liquid at a low temperature for an extended period of time. Simmering is a gentler form of stewing, and is often used to cook delicate foods such as fish or vegetables.