A sour milk smell can be removed by using coffee grounds. When the unused grounds are sprinkled over a patch of sour milk and then vacuumed up after a few hours, it should get rid of the smell.
Another good method of getting rid of a sour milk odor is to use vinegar on it. This can be as simple as placing a bowl filled with vinegar in the area that has been affected. For a more direct application, the vinegar can be sprayed right onto the carpet or wherever else the smell is coming from. Then, a steam cleaner or a cloth can be used to blot it up. An enzyme cleaner is another option as it cleans up the proteins that have been left behind from the sour milk.
Clothing can be soaked in cool water with a laundry pretreatment product, oxygen bleach, or, if the clothing can be bleached, chlorine bleach. Fill the washer with cold water, then add the clothing to the washer as soon as possible to remove both the odor and the stain left behind by milk. Housecleaning Central states that clothing that can be bleached can also be treated with lemon juice to remove stains and odors. Squeeze lemon juice onto the affected area and place the clothing in the sun until the lemon juice has dried, then wash as usual to remove odors.
When milk has been spilled inside a car, it's important to use caution in removing it. First, the source of the smell should be located and the spilled milk blotted up. Then, a large damp sponge and cold water can be used to clean the patch. Distilled white vinegar can be sprayed on the stain and a toothbrush used to scrub it. A wet-dry vacuum must be used to suck up the moisture afterwards.
Baking soda is good for removing the smell of sour milk from carpets. A toothbrush must be used to really work the baking soda into the weave of the carpet. This will help to neutralize the smell.