What Causes My House to Smell Sour?

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Each house has a distinct smell, a potpourri of odours made up of perspiration, pet odours, debris, cooking odours and stale air. Often an unpleasant odour goes unnoticed by the house's occupants, who have become so used to the smell that they might only notice when they leave for a few days and return. Finding out what is causing your house to smell sour is the first step in freshening air quality.

Obvious Causes

The obvious sources come from smells you add to the environment on a regular basis, such as cigarette or cigar smoke, and full ashtrays. Cooking certain foods, such as broccoli and fish also adds unpleasant odours that linger and cause a home to smell sour. Another obvious cause is the cat's litter box.

Potential Problem

The unpleasant odour might be an indication of another problem with the home. The smell might be coming from water damage, due to water leak or problem with the septic system. Maybe a rodent got into your walls and died. Check your basement, refrigerator, bathroom and kitchen sinks, dishwasher food filter or garbage disposal for possible sources.


A sour and stale smell can be the result of stagnant air, especially probable after closing up a house for a season, with minimal air circulation and no fresh air added to the room. Throwing open the windows and turning on a fan helps to improve the air. Another consideration, check the air filters on the heating or air conditioning unit, which might need changing.


A pile of dirty laundry typically smells and if there are piles of dirty laundry lingering in your home, they could be the cause. Don't let piles of dirty laundry sit for an extended period. A wet towel left in the laundry bin can make the entire bin smell. Maybe the sheets need changing or it is time to wash the bed pad. When you sleep at night, body odours work their way into your bed and bedding. Give the bed mattresses a sniff and see if they need freshening.


While recycling is good for the environment, keeping empty food and milk cartons in the home will cause the house to smell sour. Move your recyclable empties out of the house. Empty your trashcans once a day, taking the trash outside to avoid odour build up. Yet, it might not be the current trash causing the odour, what previous loads of trash left behind can be the source. Regularly wash your trashcans.

Pet Odors

Even after you take Rover to the groomers, the previous unpleasant smell may still be making your house stinky. Perhaps it is time to clean the carpet, upholstery and dog bed. Check the birdcage and fish tank, which may need cleaning.

Spring Cleaning

You don't have to sniff a clean sock and then a dirty sock to know which will certainly smell bad. The same is true for your house. Your house may need good overall spring cleaning to get rid of the sour smell. Sprinkle a little baking soda over the carpet and upholstery, and let it set for about 30 minutes before vacuuming up. Leave a bowl of white distilled vinegar in each room for one night, as they will absorb the rooms' odours. Kitty litter also works.

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