Grease Clog in Kitchen Sink? Here's How to Clear It

You finish cooking bacon. The pan is greasy. You rinse it under hot water, watching the suds swirl down the drain. Seemed fine. But that grease—along with every other bit of cooking oil you've poured down over the months—has been coating the inside of your pipes.

Now your kitchen sink drains slowly. Or maybe it stopped draining altogether. The culprit is almost certainly grease buildup—the number one cause of kitchen sink clogs.

This guide shows you how to clear grease clogs yourself and when professional help is needed.

How Grease Causes Kitchen Sink Clogs

Understanding how grease clogs form helps you fix and prevent them.

The Science Behind Grease Clogs

Grease appears liquid when hot—but as it travels through your pipes and cools, it solidifies and sticks to pipe walls. This happens because:

• Pipe water is usually cooler than the grease coming from your sink
• Grease molecules bond to metal and PVC surfaces
• Layer after layer, the opening narrows
• Food particles, soap residue, and minerals get trapped in the grease

Common Sources of Grease Clogs

You might be surprised how much grease goes down your drain without thinking:

• Bacon grease and cooking oil from frying
• Butter and margarine
• Olive oil and vegetable oil from salad dressings
• Pan drippings from meat cooking
• Food oils from canned foods like tuna
• Salad dressing and mayonnaise

Why Grease Clogs Keep Coming Back

If you've cleared a grease clog only to have it return weeks later, the problem is buildup on pipe walls that DIY methods can't fully remove. Professional drain cleaning—particularly hydro jetting—completely removes the grease coating and restores full pipe diameter.

How to Clear a Grease Clog

Try these methods in order. Each one targets grease in a different way.

Method 1: Dish Soap + Hot Water

Best for: Light to moderate grease buildup

Time: 10–15 minutes

Dish soap is designed to break down fats and oils—the same principle that makes it effective for greasy dishes.

1. Boil a kettle of water (or use very hot tap water for PVC pipes)
2. Add 2–3 tablespoons of dish soap directly into the drain
3. Slowly pour half the hot water down the drain
4. Let sit for 5 minutes—this gives the soap time to work
5. Pour the remaining hot water
6. Wait a few minutes and check if drainage improves
7. Repeat if needed

Method 2: Baking Soda + Vinegar + Hot Water

Best for: Mild grease buildup and regular maintenance

Time: 15–20 minutes

1. Pour half a cup of baking soda down the drain
2. Add half a cup of white vinegar
3. Watch the fizzing reaction—it helps dislodge loose particles
4. Wait 10–15 minutes
5. Flush with a pot of boiling water
6. Follow with hot tap water for 1 minute

Note: This method works better for prevention than for clearing established clogs.

Method 3: Plunge the Drain

Best for: Standing water with grease as the cause

Time: 10–15 minutes

1. Fill the sink with 2–3 inches of water
2. Use a cup plunger (not a toilet plunger)
3. Block the overflow hole with a wet rag
4. For double sinks, block the second basin with a cloth
5. Plunge vigorously for 20–30 strokes
6. Check if water drains freely
7. Follow with dish soap + hot water treatment

Method 4: Clean the P-Trap

Best for: Grease clogs that don't respond to plunging

Time: 20–30 minutes

1. Place a bucket under the P-trap
2. Loosen the slip nuts on both ends
3. Remove the trap—this is where grease often accumulates
4. Empty water and solid grease into the bucket
5. Scrub the inside with a bottle brush and dish soap
6. Rinse thoroughly with hot water
7. Check the wall pipe for additional buildup
8. Reassemble hand-tight
9. Run water and check for leaks

Method 5: Drain Snake for Deep Grease Clogs

Best for: Grease buildup beyond the P-trap

Time: 20–30 minutes

1. Remove the P-trap first
2. Insert the drain snake into the wall pipe
3. Feed the cable while turning clockwise
4. Work through resistance—this is the grease breaking up
5. Pull the snake out and wipe debris
6. Repeat until you feel smooth pipe walls
7. Reassemble the P-trap
8. Flush with very hot water

For thick grease accumulation, our technicians use hydro jetting equipment that blasts high-pressure water to completely remove grease from pipe walls. Get a quote today.

When to Call a Plumber for Grease Clogs

Get professional help if:

• Multiple methods haven't cleared the clog
• The clog cleared but came back within weeks
• You've repeated P-trap cleaning with the same result
• Other drains are also slow
• You want a permanent solution to recurring grease problems

Professional drain cleaning removes grease buildup that DIY methods can't reach. For severe cases, emergency plumbing service is available 24/7.

Cost to Clear a Grease Clog

Method	Cost	Notes
DIY (dish soap, boiling water)	$0–$5	Most effective for light buildup
Professional P-trap cleaning	$85–$150	Clears grease trapped in the trap
Drain snaking	$150–$300	Breaks through deeper grease blockages
Hydro jetting	$300–$600	Complete grease removal from pipe walls—longest-lasting
Camera inspection	$100–$250	Diagnoses hidden buildup or pipe damage

How to Prevent Grease Clogs

The best way to deal with grease clogs is to prevent them:

• Never pour grease down the drain—put it in a jar or can, let it solidify, throw it away
• Wipe greasy pans with a paper towel before washing
• Scrape plates before rinsing to remove food and oil
• Use a drain strainer to catch food particles
• Run hot water after each use to flush oil before it solidifies
• Weekly: Pour dish soap and hot water down the drain as maintenance
• Monthly: Use baking soda + vinegar + boiling water

Frequently Asked Questions