Vinegar should be part of your laundry arsenal for a number of reasons, not the least of which is that it helps protect dark jeans from fading. According to "Reader's Digest," vinegar not only helps whiten whites, but it also helps prevent your black skinny jeans from becoming an unsightly shade of gray. Although vinegar has a strong smell in the bottle, you won't smell it in your jeans once you've added soap and rinsed and dried your laundry.
Wash your brand-new jeans with vinegar before wearing them to help set the dye. Set your washing machine for a small load on the delicate cycle. Add one cup of white vinegar to a cold-water wash. Do not use soap. Turn the jeans inside out and toss them into the wash by themselves or with other brand-new jeans.
Soak new jeans in the bathtub if you prefer to not put them in the washing machine. Lay the jeans flat on the bottom of the tub and fill the tub with just enough cold water to cover them. Add one cup of vinegar and stir the water around with your hands. Let the jeans soak overnight and rinse them in clear water the following morning.
Wear your jeans five to six times before washing them again. The second time you wash, use cold water and mild detergent. If your jeans are dark, choose a laundry detergent made for dark clothes. Always turn them inside out.
Add one cup of vinegar to the wash cycle every time you wash your jeans. If you wash them in the tub or by hand, add one cup of vinegar to the wash water.
Hang your jeans inside out and allow them to air-dry.