The Overnight Bicarbonate of Soda and White Vinegar Trick for a Smelly Kitchen Sink Drain

Waking up early, making a coffee and then getting hit by a strange smell coming from the kitchen sink is more common than you might think. The good news is there’s an easy, no-fuss trick using everyday cupboard staples that can get rid of that odour overnight.

The secret hiding in your cupboard

The real hero of this overnight fix is bicarbonate of soda, paired with a splash of white vinegar. Used together, they work inside the sink drain to neutralise built-up grease, tiny (often invisible) food particles and the bacteria that cause that lingering bad smell.

It’s also about as budget-friendly as it gets. Simply tip around 120 ml of bicarbonate of soda straight into the drain, follow with about 240 ml of white vinegar, and leave it to work until the next morning. While you sleep, the chemical reaction does the hard work, breaking down the grime that a sponge can’t reach.

• Bicarbonate of soda: neutralises smells and helps loosen greasy residue in the pipework.
• White vinegar: tackles bacteria and boosts the effect of the bicarbonate of soda.
• Hot water: finishes the job in the morning by flushing away loosened debris.
• Essential oil drops: optional, for a light, fresh scent.
• Contact time: leaving it overnight is ideal for the most complete result.

Why this trick works best overnight

During the day, the kitchen sink is in constant use. Every time you turn the tap on, the mixture gets diluted and washed away before it has time to fully do its job. Overnight, the drain gets a break, giving the ingredients hours to soak deeper into the pipework and break down stubborn build-up.

It’s the same idea as soaking a burnt pan: time does the heavy lifting for you. In the morning, run very hot water from the tap for about a minute and the sink should be odour-free, with noticeably faster drainage.

The details that make all the difference

Before you use the mixture, it’s worth taking a quick extra step: remove any visible bits of food from the drain and wipe the sink with a clean cloth. That way, the reaction isn’t wasted on the surface and can focus where it matters most-inside the pipes.

Step-by-step for an overnight clean

Simple, effective application

Pour around 120 ml of bicarbonate of soda directly into the sink drain. Next, add about 240 ml of white vinegar and watch for gentle fizzing-this is the sign the reaction is working.

Leave it overnight without using the sink. In the morning, run hot water for about a minute to finish off. That’s it: the smell disappears and the water should flow much more freely.

Frequency matters too. Doing this once a week is usually enough to keep a kitchen sink free from odours. In a busy household-lots of cooking, frequent frying or plenty of people-doing it twice a week can help prevent build-up.

More than cleaning: a routine that saves money

This homemade approach doesn’t just remove bad smells-it can also help prevent bigger plumbing issues. Grease build-up over time is a major cause of blockages, and clearing it regularly means spending less on a plumber and avoiding harsh chemical products.

It’s also a more environmentally considerate option. Unlike industrial drain unblockers, bicarbonate of soda and vinegar won’t harm your pipework or contaminate the water that runs into the sewer. It’s effective cleaning with a more mindful footprint.

Other night-time habits that help keep the kitchen in order

People who adopt this little routine often add a few other end-of-day habits too: wiping the worktop with vinegar, leaving a small bowl of coffee grounds near the sink to absorb smells, and taking out the food waste. Small actions that make the whole house feel fresher first thing.

When you get down to it, keeping the kitchen smelling clean doesn’t require expensive formulas or fancy products. Sometimes the answer is that tub of bicarbonate of soda forgotten at the back of the cupboard-ready to make a difference while the house is asleep.

If this tip helped you look at your kitchen sink in a new way, pass it on to a friend or relative who’s always moaning about that annoying drain smell. You’ll be doing them a real favour.