Thanksgiving sides in a slow cooker: what to cook, what only to hold, and the safety rules

On a one-oven Thanksgiving, slow cookers take sides off the oven schedule. They work best for two jobs: cooking a side from raw over a few hours, and holding a finished side hot on the buffet. The job they're bad at is the one people try most: warming yesterday's casserole from the fridge. USDA FSIS and Colorado State University Extension both say not to reheat leftovers in a slow cooker, because it heats food too slowly.

Cook or hold: sort the sides

Side	Slow cooker job	How
Mashed potatoes made that day	Hold	Make them on the stove, then hold on low or warm, stirring now and then, at 140°F or above
Potatoes, sweet potatoes, root vegetables from raw	Cook	Vegetables go in first, then the recipe's liquid; lid on; fill half to two-thirds
Cranberry sauce from fresh berries	Cook	Berries, sugar and liquid, lid on; serve warm or chill
Stuffing (dressing) cooked outside the bird	Cook or hold	Cook in the crock or bake ahead; either way it must reach 165°F
Make-ahead casseroles (green beans, mac and cheese, sweet potatoes) from the fridge	Hold only	Reheat to 165°F in the oven or microwave first, then into a preheated cooker
Gravy	Hold only	Bring it to a boil on the stove (FDA's advice for reheating gravy), then hold in a small crock
Hot cider or other drinks	Hold	Heat on the stove or in the cooker, then keep on low

The make-ahead list in the make-ahead guide tells you which dishes can be made days ahead; this page is about getting them hot again and keeping them that way. Oven backups, a chafing dish and a clean cooler are on how to keep Thanksgiving food warm.

The rules, step by step

1. Start clean, and wash your hands for at least 20 seconds (CSU).
2. Set it on a dry, stable surface with at least 2 inches of space around it, plugged straight into a wall outlet. CSU says to avoid extension cords. If you're running several cookers, spread them across outlets rather than one power strip.
3. Fill it half to two-thirds full. Less or more and it won't heat evenly, CSU says.
4. Put vegetables in first. FSIS says vegetables cook more slowly than meat in a slow cooker, so they go in first, followed by the liquid the recipe calls for.
5. Start on high if you can. FSIS and CSU both suggest the first hour on HIGH, then low. CSU adds about one more hour on LOW for every 4,000 feet of altitude; the high-altitude guide covers the rest of the meal.
6. Keep the lid on. Each lift costs 10 to 15 degrees and about 20 minutes to recover, according to CSU. Stir mashed potatoes or stuffing only when you need to.
7. Reheat cold dishes elsewhere first. To 165°F on the stove, in the microwave or in the oven, then into a cooker that's already hot.
8. Hold at 140°F or above. Check with a thermometer after the first hour on warm. FDA says some warming units only hold 110 to 120°F; if yours reads below 140°F, turn it to low.
9. Leftovers out within 2 hours. CSU says to move leftovers out of the cooker, into shallow covered containers, and into the fridge within two hours of cooking finishing. The leftovers guide has the storage times.

A sample plan for 12

• Wednesday: bake the sweet potato casserole and green bean casserole and refrigerate them. Make cranberry sauce in a slow cooker and chill it.
• Thursday morning: peel the potatoes. Stuffing goes into cooker #1 on high for the first hour, then low.
• Turkey out, resting: this is when the oven is free. Reheat both casseroles in it to 165°F. Mash the potatoes on the stove and move them to cooker #2 on warm. Bring the gravy to a boil and put it in a small crock or one insert of a triple server.
• Dinner: stuffing, potatoes and gravy sit on the buffet in their crocks, each with its own spoon. Casseroles come straight from the oven.

The one-oven schedule shows how that turkey-resting window lines up, and the sides timing guide has the stovetop side of the plan.

On the buffet

Slow cookers are the simplest way to meet FDA's buffet rule for hot food: 140°F or warmer, or out after 2 hours (1 hour above 90°F). Set them at the back of the table where cords can't be pulled, away from the table edge if small children or older guests are reaching past. The buffet guide covers the full layout, and the pet safety guide has the reasons to keep cords and crocks out of a dog's reach.

If the power goes out

FSIS's rules: if you're out and the power fails, throw the food away even if it looks done. If you're home, finish cooking it another way at once. Food that was already fully cooked is safe in the cooker for up to 2 hours with the power off. The oven-broke and power-outage plan covers the rest of the meal.

Test an old slow cooker now

CSU Extension's check for an older cooker: fill it half to two-thirds with tap water, heat on LOW for 8 hours with the lid on, then check the water quickly with a thermometer. It should read 185 to 200°F. Below 185°F, it isn't heating food fast enough and should be replaced. Do this the weekend before Thanksgiving, not the morning of.