Gravy

Gravy keeps 3–4 days refrigerated and 2–3 months frozen, and it should be treated as one of the more perishable things on a holiday table rather than an afterthought.

Get it into the refrigerator within two hours, in a shallow container rather than left in the roasting pan or a deep gravy boat. It cools much faster spread out.

Reheat gravy to a full rolling boil, not merely to warm. This is standard USDA advice for gravy specifically, and it exists because gravy is made from meat drippings and is often held warm for long periods during a meal.

Do not hold gravy on a warm setting for hours across a long dinner. Keep it above 140°F if it must be held, or refrigerate it and reheat portions as needed.

Gravy freezes acceptably though flour-thickened versions may separate on thawing — whisk hard while reheating and it usually comes back together.

Gravy is essentially a meat broth thickened with starch, which combines two risk profiles into one sauce.

From the meat drippings it inherits a rich supply of protein and a near-neutral pH. From the flour or cornstarch it inherits the Bacillus cereus concern that applies to cooked starches. And because it is customarily kept warm on the stove or in a gravy boat throughout a long meal, it spends extended periods in or near the bacterial growth range.

Clostridium perfringens is the specific organism most associated with gravy. Its spores survive the simmering, it grows in low-oxygen environments, and it multiplies extremely fast between 70 and 125°F. Gravy left to cool slowly in the pan after a large meal — a Thanksgiving pattern — is one of the most cited scenarios for it in USDA materials.

This is why the reheating instruction is a full boil rather than the 165°F used for solid leftovers. Boiling reliably destroys the vegetative cells throughout a liquid that may have cooled unevenly.

Gravy that has turned smells sour rather than savory, may develop a fizzy or bubbling appearance when cold, and can turn ropy or slimy. Mold on the surface means discard the whole container.