Kitchen Sink Smells? 8 Quick Fixes For Common Causes

Not too many household problems are as unpleasant as foul kitchen sink smells drifting through your home. But what makes it particularly tricky is that the smell itself doesn’t always mean the same thing – and the fastest fix depends entirely on why it’s happening. For instance, a greasy buildup needs a completely different remedy than a dry trap – and treating the wrong cause often means the smell comes right back.

So before you call in a professional or start your favourite DIY routine for smelly drains, it’s worth understanding the most common and distinct reasons drains smell – and the quickest DIY fixes that often solve the problem short term.

1. Food and grease buildup in the pipe

If your kitchen sink smells bad after washing the dishes, the most common culprit is:

• Grease
• Food scraps
• And soap.

The foul combination clings to the inside of the drain – and, over time, the buildup goes rancid and releases its odours. If the weather has just warmed up and the smell has gotten worse, this is almost certainly the cause.

THE QUICK FIX:

• Boil a full kettle of water
• Slowly pour it down the drain to soften grease
• Follow with a cup of bicarb soda and a cup of white vinegar.
• Let it all fizz for 10 minutes, then flush with hot water again.

2. Bacteria feeding on organic residue

When a kitchen sink drain smells bad but isn’t blocked, bacteria are often thriving on microscopic food waste inside the pipe. This produces a sour or rotten-egg smell that lingers.

THE QUICK FIX:

• Pour half a cup of baking soda down the drain
• Follow up with hot water.

This helps neutralise odours and slow bacterial growth. Avoid harsh chemical cleaners – they can actually make the smell return faster.

3. Dry or faulty P-trap

If the smell appears suddenly and resembles sewer gas, the issue may not be dirt at all. Many homeowners ask why kitchen sink smells like sewer – and the answer is often a dry P-trap that’s no longer holding a water seal.

THE QUICK FIX:

• Run the tap for 30-60 seconds to refill the trap
• If the sink isn’t used often, repeat every few days.

Also, check for slow leaks underneath, as these can empty the trap without you noticing.

4. Biofilm lining the drain walls

A slippery film called biofilm can coat the inside of pipes, creating persistent odours even when the drain looks clean. This is a common reason why my kitchen sink drain smells despite regular rinsing.

THE QUICK FIX:

• Use a bottle brush or flexible drain brush to scrub inside the drain opening
• Follow up with hot water to flush loosened residue deeper through the system.

5. General organic decay in household drains

When multiple fixtures smell, you’re likely dealing with broader smelly drains caused by organic material breaking down across the plumbing system.

THE QUICK FIX:

Flush each drain with hot water and a small amount of mild dish detergent to help loosen residue. This can temporarily reduce odours throughout the home.

6. Sink stopper and overflow buildup

Sometimes, the pipe isn’t the problem at all. The rubber stopper and overflow channel collect soap scum and hair, creating a smelly kitchen sink drain even when water is flowing freely.

THE QUICK FIX:

• Remove the stopper
• Scrub it thoroughly
• Clean inside the overflow hole using a small brush and warm soapy water.

7. Minor blockages restricting airflow

A partial blockage can cause stagnant water and poor ventilation – leading to unpleasant smells. Learning how to clean sink drain openings properly helps restore airflow.

THE QUICK FIX:

• Use a small plunger to dislodge debris
• Follow up with hot water

Just be aware of not pushing the stinky material deeper with improvised tools.

8. Residual odours after cleaning

Even after cleaning, some homeowners struggle with kitchen sink drain smells returning even just a few days later.

THE QUICK FIX:

• Drop a few citrus peels into the drain
• Run the cold water
• Briefly activate the disposal if you have one.

This can mask odours short-term – but doesn’t remove the cause.

When odours persist despite cleaning

Have you tried multiple quick fixes and you’re still wondering how to get rid of smells from kitchen sink drains? Unfortunately, the problem almost certainly sits deeper in the system.

At this point, forget the quick fixes – repeated DIY treatments can actually compact the debris further down the line, making it harder even for a professional drain plumber to deal with the issue.

Don’t forget, DIY remedies work best when smells are caused by surface buildup or minor residue, not:

• Deeper pipe contamination
• Root intrusion
• Damaged pipes
• Sewer ventilation issues.

They’re all problems that can cause persistent odours that no home remedy will fix. When smells return quickly, worsen, or affect multiple fixtures, it’s a sign the underlying issue needs professional attention.

A licensed drain specialist can:

• Inspect the system with CCTV drain cameras
• Clear buildup using high-pressure jetting
• Identify structural problems that allow odours to escape.

These long-term solutions don’t just remove smells – they usually prevent them from coming back for a long time.

When to call a professional

Does your sink simply stink after every clean? Are those odours spreading throughout the house? Is water draining slowly on top of your bad sink smells? It’s definitely time for expert help – because addressing the root cause as early as possible prevents bigger plumbing issues and protects your pipes long term.

Just need help with persistent drain smells today? Get in touch with Brisbane Drain Cleaning for fast diagnostics and long-lasting solutions that keep your drains flowing cleanly – odour-free!