How to Remove the Odor of Sour Milk from Your Car

car interior showing a milk cup

If you accidentally spill milk in your car, first, you have to deal with cleaning it up and then, a few days later, you will have to deal with a strong unpleasant odor of spoiled milk.

Milk can soak down deep into the upholstery or carpet of a car and leave a disgusting smell that can linger for weeks or even months. Properly cleaning up the mess and then dealing with smell is key to making sure your vehicle doesn’t become unusable due to the strong scent of sour milk.

While a quick spray of Febreze or installing a pine tree air freshener will briefly improve the smell of your car, the rotten milk smell will be back soon enough if it is not addressed directly.

Follow this step-by-step guide to ensure that you properly clean up the mess and eliminate the odor of the spilled milk.

Part 1 of 2: Clean up the spill

Materials Needed

  • Carpet cleaner
  • Charcoal bags
  • Clean white cloth or paper towels
  • Dishwashing soap
  • Hose or pressure washer
  • Sponge
  • Stain remover (optional)
  • Steam cleaner (optional)

The first thing that needs to be dealt with is the spilled milk, and clean it up quickly.

milk being sopped up from the seat

Step 1: Soak up the milk. Never let any spill absorb or sit - a quick response is key if you want to prevent an increasingly disgusting smell from filling up your car.

Use a clean white cloth or paper towels to soak up all wet and visible milk. It is best to pat dry the spill as scrubbing it can push the milk further into the carpet or upholstery.

  • Tip: A sponge is also useful for absorbing spills on the seats or leather upholstery.

Step 2: Pull out the floor mats. If any milk has spilled on the floor mats, they should be taken out of the car and washed.

If the milk is allowed to stay on the floor mats it will eventually sour and the odor will fill the entire car.

You can put floor mats made from fabric or carpeting in a washing machine. Wash them at the hottest setting advised on the care label or your vehicle owner's manual.

If the floor mats have a rubber backing or are made from plastic, spray them off with a hose or pressure washer, and use dishwashing soap on the stain.

Allow the mats to air dry out in the sun, on a flat surface.

If the vehicle has removable seat covers, take them off and wash them according to the manufacturer’s cleaning instructions.

  • Tip: Take out any carpet or fabric in the car that can be removed and wash it if the milk has stained it.

steam cleaner being used to remove milk

Step 3: Rent a steam cleaner. If the spill was significant, or if it has penetrated into the surface, rent a steam cleaner to ensure that you get out any deep-set milk.

A steam cleaner provides a deep clean by spraying cleaning solution and hot water onto the carpet or fabric, and removing the water and dirt. This will help pull out any odor-causing residue of the milk.

Follow the directions on the steamer and change the water frequently. Leave the carpet or upholstery to dry for 12 hours after the cleaning.

  • Tip: You can rent steam cleaners at a rental store or buy them at most grocery stores.

Step 4: Consider a professional. If the spill, or more likely, the odor is still present, you may need to bring in a professional.

  • Tip: As pricing can vary dramatically between different cleaners, ask friends and family for recommendations to find reliable and affordable cleaning services.

Part 2 of 2: Remove the smell

Materials Needed

Use any of the following methods to get rid of odors:

baking soda being applied to a car seat

Method 1: Baking soda. Baking soda helps to pull out and absorb bad odors.

After the spill area has completely dried, shake enough baking soda to cover the affected area. Let the baking soda sit on the spot for three or four days, and then vacuum it up.

If the smell is still present, repeat these steps, or move on to one of the other methods outlined here.

Method 2: Coffee grounds. Much like baking soda, coffee grounds will absorb bad odors while also leaving your vehicle with a pleasant coffee scent.

  • Tip: Leave plastic containers filled with coffee grounds underneath your car seats for roughly two weeks. This should help remove the odor of spoiled milk from the car.

bottle of vinegar being sprayed on a milk stain

Method 3: White vinegar. Spraying vinegar on the carpet or upholstery will help break down the enzymes in the spilled milk, removing the odor from the car. It is also chemical free and completely safe to use.

  • Tip: Unless you want your vehicle to have an extremely strong vinegar smell, always mix the vinegar with water. Use a spray bottle and mix four parts water to one part vinegar. Spray the spill area until it is drenched with the vinegar mixture. Allow it to soak for five hours and then blot it dry with a clean washcloth.

It’s best to leave the vehicle’s windows open, to allow it to air out.

Method 4: Enzyme sprays. If the odor is still there, it’s time to use commercially available enzyme sprays to get rid of the smell.

Enzyme sprays are environmentally friendly and use proteins and enzymes to break down the molecular structure of stains. Enzyme sprays are activated when they are hit a stain or odor, and the bacteria eats away at the matter while eliminating the odor.

  • Tip: Enzyme sprays are available at most home improvement stores or online.

Spray the enzyme product on the stained area and allow it to sit for a day or two before blotting it up.

  • Note: These sprays should not be used on leather interiors. Always do a test spot to check for staining.

cleaner being applied

Method 5: Carpet cleaners. A home carpet cleaner should work well on carpeted floor mats or any carpeted areas in the vehicle.

Follow the manufacturer’s instructions given on the cleaner labels. In most cases the product should be allowed to sit for an hour and then vacuumed up.

Method 6: Charcoal bags. After the stain has been cleaned up, consider putting an all-natural product like charcoal bags in the car.

These bags come in a variety of shapes and sizes and are filled with bamboo charcoal that soaks up any lingering bad odors.

Step 1: Air out the vehicle. After the spill has been cleaned up, leaving the car windows open will help air out the odor.

  • Tip: The sunshine will also help dry the stain and break down the odor.

Accidental milk spills from baby bottles or milkshakes can happen when you least expect it. Keep these tips handy so that you are prepared to tackle these spills quickly when they happen. If you still find a bad odor lingering in the car even after these steps, it may be due to other issues in the car. It is best that you get a certified mechanic, such as one from YourMechanic, to perform an inspection and determine the source of the problem.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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