Can You Pour Cooking Oil Down the Drain? What to Do Instead
By Mike Holt, NJ Master Plumber · April 12, 2024 · 2 min read · Updated November 1, 2026
Quick answer
No. Cooking oil and grease cool and stick to the inside of your pipes, then trap food scraps and soap until the drain clogs. Hot water and dish soap only move the grease a little farther down the line. Let it cool, pour it into a can or jar with a lid, and put it in the trash, or recycle large amounts if your town takes it.
Want us to take a look? We find the cause and give you written upfront flat-rate pricing options before any work starts.
Pouring bacon grease or frying oil down the sink seems harmless when it's warm and runs right down. The trouble starts a few feet into the pipe, where it cools and sticks. Over months it builds into a clog that a plunger can't move.
Why is it bad to pour oil down the drain?
Fats, oils and grease (plumbers and sewer authorities call them FOG) are liquid when hot and turn soft or solid as they cool. In your drain they coat the inside of the pipe in thin layers. Each layer catches food scraps, coffee grounds and soap, and the opening keeps getting smaller until the sink backs up.
The grease that gets past your house doesn't disappear either. In town sewers it combines with wipes and other debris into large blockages that sewer crews have to cut out, and it can cause sewage overflows.
Does hot water and dish soap help?
It feels like it should. Hot water keeps grease liquid for the first few feet, and soap loosens it from the pan. Then the pipe cools it down and it settles farther along the line, often under the floor or in the main line where it's harder to reach. Running hot water after grease just moves the clog farther down.
How do you get rid of cooking oil the right way?
| Amount | What to do |
|---|---|
| A film of grease in a pan | Wipe it out with a paper towel before washing, and put the towel in the trash |
| A few spoonfuls to a cup | Let it cool, pour it into a can or jar with a lid, and put it in the trash |
| A lot (turkey fryer, deep fryer) | Let it cool, keep it in its original jug, and check your town or county recycling program |
| Oil you want to reuse | Strain it into a sealed container and keep it in a cool place |
A few more habits help:
- Scrape plates into the trash before rinsing.
- Use a sink strainer to catch food.
- Keep grease and oily scraps out of the garbage disposal. It grinds food, but grease goes straight through and hardens below.
Our guide to keeping drains from clogging covers the rest of the house.
What if your kitchen sink is already slow?
Start with the steps in how to unclog a kitchen sink: plunging, cleaning the trap and checking the disposal. Skip chemical drain cleaners. They rarely clear grease and they can damage older pipes.
If the sink keeps clogging, the grease is usually farther down the line than a plunger reaches. A snake opens a path through it. When grease coats a long stretch of pipe, hydro jetting cleans the pipe walls. Our guide to snaking vs. hydro jetting explains the difference.
Plumbing Doctor clears kitchen and main line clogs across Central New Jersey. See our drain cleaning service, or call 908-873-6686. Written upfront flat-rate pricing options. You choose. The $49 service call covers the trip and is waived if you go ahead with the work.
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Stop and call us if
- The kitchen sink stays slow after plunging or cleaning the trap.
- Water backs up into the other side of a double sink or into the dishwasher.
- Several drains are slow, or the lowest drain in the house gurgles or backs up.
- The sink clogs again within a few weeks of clearing it.
Call 908-873-6686.
Michael Holt
Owner and operator of Plumbing Doctor, NJ Master Plumber (Lic. #36BI01345600) and U.S. Marine Corps veteran.
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