What Not to Put Down the Garbage Disposal on Thanksgiving

On Thanksgiving, keep turkey grease and pan drippings, potato peels, turkey bones, celery, onion skins, corn husks, pumpkin pulp, stuffing, rice and coffee grounds out of the garbage disposal. These foods either harden in the pipes, swell into paste or wrap around the grinding parts, and a holiday’s worth of them at once is the most common reason kitchen sinks back up that weekend. Scrape plates into the trash or compost, let grease cool in a container, and run only small amounts of soft scraps through the disposal with plenty of cold water.

Plumbing companies call the day after Thanksgiving “Brown Friday” because it is one of their busiest days of the year. More people are cooking, more dishes are being rinsed, and guests often feed the disposal things the household would normally throw away.

Why is turkey grease so bad for a garbage disposal?

Turkey grease is liquid when hot and turns solid as it cools in the drain pipe, where it traps food particles and narrows the pipe until water stops flowing. Running hot water while pouring it only moves the problem a few feet further down the line, and dish soap does not keep it dissolved for long. The same applies to butter, gravy, bacon fat, meat drippings and the oil from a turkey fryer.

Fats, oils and grease are a major cause of sewer blockages, and many city utilities ask residents to keep them out of drains for that reason. What to do with grease instead:

Let it cool, pour it into a can or jar with a lid, and put it in the trash once it sets.
Wipe greasy roasting pans and skillets with a paper towel before washing them.
Strain large amounts of fryer oil and check whether your city or a local recycling center accepts used cooking oil.

Can potato peels go down the disposal?

Potato peels should go in the trash, because the starch turns into a thick paste when ground and the thin skins can slip past the blades and collect in the trap. A few peels may pass through without trouble. A whole bag’s worth of peels for holiday mashed potatoes, ground in one session, is the classic Thanksgiving clog. The same starch problem applies to sweet potato skins, leftover stuffing, bread, rice and pasta, which all absorb water and swell. Our article on what happens when bread goes down a disposal explains how that paste forms.

What about turkey bones and the carcass?

Turkey bones and the carcass belong in the trash or the stockpot, never in the disposal. Large poultry bones are too hard for a home disposal to grind, and they can jam the flywheel, dull the impellers or crack the grinding chamber. Small fish bones or a chicken wing bone may get through a strong unit, but a holiday bird is a different job. Making broth from the carcass uses it up and leaves nothing for the sink.

Which vegetables cause the most trouble?

Fibrous and stringy vegetables cause the most trouble, because their long fibers wrap around the turning parts instead of being ground. Keep these out:

Celery stalks and leaves
Onion skins (the thin outer layers stick to the chamber walls)
Corn husks and corn silk
Asparagus ends and artichoke leaves
Pumpkin and squash pulp, strings and seeds
Green bean ends in large quantity

Onions themselves are a smaller risk than the skins; the article on putting onions in a garbage disposal covers the difference.

What else should stay out on a busy cooking day?

Coffee grounds, eggshells, fruit pits and nonfood items should stay out of the disposal, especially when it is already working hard. Coffee grounds and eggshell fragments settle in the trap like sand and build up with grease. Cranberry sauce in small amounts is fine, but avocado pits, peach pits and nut shells are too hard. Twist ties, toothpicks, foil and the plastic pop-up timer from the turkey are frequent causes of a jammed unit after a party. For the full year-round list, see what not to put in a garbage disposal.

How should you use the disposal on Thanksgiving?

Use the disposal for small amounts of soft food at a time, with cold water running before, during and after grinding. Cold water keeps any traces of fat solid so the blades can chop them and the water can carry them away. A simple routine for the day:

Set a trash bag or compost bowl next to the sink and scrape every plate into it first.
Put only soft leftovers in the disposal, a handful at a time.
Run a strong flow of cold water, turn the disposal on, and let it run until the grinding sound changes.
Keep the water running for 15 to 30 seconds after the disposal goes quiet.
If you have a dishwasher on the same drain, avoid running it while the sink is filling, so the drain line is not overloaded.

Guests who help with dishes may not know your rules. A short note taped inside the cabinet door above the switch saves a call to the plumber.

What should you do if the sink clogs anyway?

If the sink backs up, turn off the disposal and leave it off, then work through the simple checks before calling a plumber. Do not pour chemical drain cleaners into a disposal: they can damage the unit and splash back on anyone who later works on the drain, and they should never be mixed with other cleaners.

If the motor hums but does not turn, it is jammed. Cut the power, then use the hex key in the slot on the bottom of the unit to free the flywheel. Our guide to a garbage disposal that is not spinning walks through it.
If it is silent, press the red reset button on the bottom of the unit after it has cooled for a few minutes.
Never put your hand into the disposal. Use tongs to remove objects, with the power off at the switch or breaker.
If water still stands in the sink after the disposal runs, the clog is in the trap or the drain line. A plunger on the sink (with the other basin sealed on a double sink) often clears it. Removing the trap requires a bucket underneath.

Call a licensed plumber if water backs up in more than one fixture, if the clog returns after you clear it, or if the disposal leaks from the bottom. Those signs point to a blockage further down the line or a failed unit.

Quick answers

Can I pour gravy down the disposal if I run hot water?

No. Gravy is mostly fat and flour, and hot water only carries it further into the pipe before it cools and sets. Put leftover gravy in the refrigerator or the trash.

Is it safe to put cranberry sauce in the disposal?

Small amounts of cranberry sauce are soft and grind easily. Run cold water with it and keep the quantity small.

Should I compost Thanksgiving scraps instead?

Vegetable peels, corn husks, pumpkin pulp and coffee grounds suit a home compost pile. Meat, bones, grease and dairy do not belong in a backyard compost bin, but some city curbside programs accept them.

How long can leftovers sit out before they go in the fridge?

The USDA Food Safety and Inspection Service advises refrigerating leftovers within two hours of cooking. Food left out longer belongs in the trash.