What is Thermal Shock?

Get the basics on thermal shock, the sneaky physical phenomenon that can bring even the sturdiest cookware to its knees. 

Thermal shock in cookware refers to the sudden and extreme temperature change that can cause the material of your cookware to expand or contract rapidly, leading to cracks, warping, or fractures in the cookware. This can occur when a hot pan is placed in cold water, or when a cold pan is placed directly on a hot stove or in a hot oven. 

Cookware that is made of materials with poor thermal conductivity, such as ceramic or glass, is particularly susceptible to thermal shock, and will often crack or break completely. However, even metal cookware like stainless steel pots and pans can experience thermal shock if they are exposed to extreme temperature changes too quickly. The tell-tale signs are wobbling, spinning, and rocking when placed on a flat surface or stove top. 

A stainless steel pan affected by thermal shock will no longer sit flush on a stovetop grate or induction cooktop. While it’s still technically safe to use, it will affect heat dispersion across the surface and result in uneven cooking or heating. 

Since warped cookware is difficult to repair (and in most cases, is not covered by even the most generous of warranties and will need to be replaced outright) it’s best to be proactive. The best way to avoid thermal shock in cookware is to slowly heat or cool the cookware, rather than subjecting it to sudden and extreme temperature changes. 

1. Heat gradually. Place a cold pan on a likewise cold stove top, and let it gradually heat up to the desired temperature. Never place a cold pan directly into a hot oven, as this can warp the material. (If you’ve ever heard a sheet pan “pop” while you were roasting dinner, you’ll be familiar with this.)
2. Then, take the time to cool off. To cool a hot pan, let it return to room temperature before exposing it to cold water or placing it in a cold environment like a fridge or freezer. To help remove any stuck-on food from the cooking process (which has now cooled and tightened into a death grip) soak in warm, soapy water before scrubbing.