Rule 5 of 27 · Chapter I — Before You Cook
Bring key ingredients to room temperature first
Why this rule exists
Cold food fights the heat, and the fight shows up in the result. A steak straight from the fridge sears on the outside while the center is still refrigerator-cold, so by the time the middle is warm the crust is overdone. Cold eggs crack when they hit boiling water and refuse to emulsify smoothly into a batter. Cold butter will not cream. Temperature is an ingredient too, and starting closer to where you want to end means more even cooking and fewer nasty surprises. It is a small, patient step that costs nothing but a little foresight, and it quietly fixes problems people usually blame on their technique or their stove.
In practice
Pull the things that matter out of the fridge before you start prepping, twenty to forty minutes for meat and eggs, longer for a big roast. A thick steak or chicken breast especially benefits, because the temperature gap from surface to center is what makes even cooking hard. Let butter for baking soften on the counter until it dents easily but is not greasy. Warm eggs quickly by sitting them in warm tap water for a few minutes if you forgot. Meanwhile, keep anything meant to stay cold, like pie dough or whipping cream, in the fridge until the last second.
When it doesn't apply
Food safety sets a limit; do not leave raw meat out for hours, especially in a warm kitchen. Some things are meant to be cold when cut or cooked, like fat trimmed easier when firm, or fish for slicing. And thin cuts barely care. The rule matters most for thick proteins and for baking.