Myoglobin remains partially intact when meat is cooked at lower degrees of doneness, giving it a pink or red color. But at around 170 F (77 C), the protein denatures completely, which turns the ...

The USDA warns that if you only partially cook meat and store it in the fridge to cook later you are increasing the likelihood of foodborne illness even if you plan on fully cooking it later.

Flip and cook until meat whitens and lightly browns in spots, about 3 minutes. Remove partially cooked chicken from pot and set aside. Pour stock into the same pot and bring to a simmer.