Denim is a type of cotton or cotton-blend fabric. Cotton and other natural materials tend to absorb stains and odors easily. Your denim clothing or upholstery can retain odors, making them smell dirty even when they're not. New denim often has a new denim smell. Remove smells from your denim fabric while using precautions to make sure it doesn't shrink. While there are many laundry products available to help you freshen your denim, you can use a combination of those products and products from around the home to remove the smell.
Sprinkle baking soda over denim upholstery or other non-washable denim items. Work the baking soda into the denim with a soft-bristled scrub brush. Allow the baking soda to sit on the denim overnight to absorb unpleasant odors.
Vacuum the baking soda from your denim upholstery.
Wash new denim clothing with a new denim smell or older denim garments that have absorbed an offensive odor in cool water. Add laundry detergent and 1 cup white vinegar to the wash water. The vinegar will remove any stinky odor and freshen your denim.
Hang-dry your denim garments outdoors. Fresh air is one of nature's best fresheners and deodorizers. Hang your denim out of direct sunlight to avoid bleaching.
Treat persistent, lingering odors by sprinkling white vinegar over your denim garment, and then ironing it on the cotton setting.