How to Remove Sour Milk Smell From Your Car | AutoGuru
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5 ways to remove the sour milk smell from your car

Jason Unrau

Updated 28 Mar 2023

Jason Unrau

We all love our children, the energy and joy they bring to our lives, the precious memories we create together. But accident or not, you’ve gotta admit, we like them a little less when they spill milk in the car.

That putrid odour clings to the inside of your nostrils and reminds you of the after effects of a big night out.

And the stench simply doesn’t go away on its own. In fact, if left to fester, over time it gets worse.

And heaven forbid it happens in the summer heat when the pungency goes off the charts and you don’t dare inhale inside your car!

The source of the smell isn’t just the milk itself – it’s the bacteria that’s begun spawning in the area around it.

Removing the sour milk smell from your car certainly is a challenge, but it can be done.

So, put down your blowtorch, grab some cleaning supplies, and let’s get to work!

Mop Up the Milk Spill As Soon As It Happens

If it’s just a few drops from a sippy cup or your bub’s milk bottle, soak up the spill as soon as you notice it. The less milk to contend with, the better.

Use paper towelling or a microfibre to absorb the spill. Dab at it but don’t rub the spill spot. Rubbing pushes the milk further down into the carpet or upholstery.

Steam Clean the Spot

Whether you’ve mopped up the spill immediately or didn’t attend to it until it went rank, a good steam clean can get rid of most of the smell.

Use an enzyme-based cleaner in the water which aids in killing the bacteria safely.

But even though you’ll reduce your workload with a steam clean the spill, this method on its own is often not enough to fully eliminate a set-in sour milk smell.

The stink can return afterwards and linger, causing every drive to be unpleasant.

Apply Baking Soda

Baking soda has been used for decades to eliminate odours. It’s inexpensive, so use it liberally!

Sprinkle baking soda directly on the carpet or upholstery where the milk spill occurred. Feel free to go well beyond its original borders; the bacteria may have begun to spread.

Rub the baking soda into the fibres using a cloth or a soft-bristled brush. Let it sit at least overnight, even better if it can work its magic over three or four days if possible.

Vacuum the baking soda off the upholstery, then put your nose to it. If there’s still a sour smell, repeat the baking soda procedure again.

Clean with an Enzyme Product

Is the sour milk reek still present? It might be deeply set in. If so, it’s a job for a spray cleaner that contains enzymes.

Spray the location of the milk spill with your enzyme cleaner. If you want that smell to disappear, wet the area well. That’s it – that’s all you have to do.

If you want, you can brush the enzyme cleaner deep into the fabric with your soft-bristled brush. The enzymes break down the bacteria feeding on the milk, neutralising the odour they produce.

Pull Up the Carpet/Upholstery

If none of the above steps work, it’s time to go on the offensive. The area where the smell emanates from needs to be removed and cleaned thoroughly.

It’s not an ideal situation, and often a professional detailer needs to do it.

The milk may have seeped through your carpet or deep into the backing or foam underlay, making it virtually impossible to clean without pulling out the upholstery first.

If this is the case, you have our commiserations.

Now, imagine a seamless segue here…

Right. We may not be able to help you get that foul stench out of your carpet or upholstery (good luck with that, by the way), but AutoGuru lets you search, compare and book from over 1600 trusted mechanics across Australia. Boom!

Jason Unrau

Written By

Jason Unrau

Jason is a Canadian automotive content writer with a background in the auto service industry, but he’s been hooked on cars and mechanics since childhood.

One of his first cars was an ’80 Mazda RX-7 that’s sorely missed to this day. A ’68 Ford Torino GT, a ’66 Ford Country Squire Woodie station wagon, and a ’96 Suzuki GSX-R 750 have spent time in his fleet of cars, bikes, and trucks over the past two decades.

Jason’s pride and joy is under construction – a turbocharged ’88 Mazda RX-7 convertible. Also on his resume is CASCAR official certification.