The common belief that vinegar keeps colors from fading or bleeding is not entirely true. In fact, vinegar can actually alter the colors in some fabrics instead of preventing them from fading. Vinegar gets its colorfast reputation from when it was used to set the colors in dyes with salt on fabrics many moons ago -- which doesn't work on today's fabrics and dyes. Vinegar contains acetic acid, which may weaken fabrics made with rayon, acetate, silk or triacetate. Always test your fabrics first for colorfastness, especially when you're adding vinegar for stain or odor removal. Vinegar can, however, restore colors dulled by the alkalies in detergents, which is why many people believe it prevents fading and bleeding.
Vinegar gets its reputation for the prevention of color fading because it removes detergent buildup on fabrics, which contributes to dulling. Some of the alkalies in laundry detergents cause them to bind with the fibers in fabrics. Over time, this creates a detergent buildup on clothes, bedding and other washables. The accumulation of residue in the fibers causes the fabric's colors to look faded, dull or washed out. The acid in white vinegar cleanses fabrics of the soap buildup, allowing them to regain their brighter appearance. So vinegar doesn't keep colors from fading, it removes the buildup that blocks the fabric's true appearance. You can also use it in the washing machine to remove the buildup inside the tub.
Soft and Fluffy
Do not add vinegar to a laundry load that has been washed with chlorine bleach. As an acetic acid, it may interact with the chlorine in a negative way, creating noxious fumes. But you can add vinegar to the final rinse cycle for baby clothes, wool and cotton blankets or to remove laundry odors; it makes these items extra soft and fluffy by removing the waxy buildup caused by many detergents.
The acetic acid in vinegar can help remove stains from your laundry. Wet stained fabric with a white vinegar that contains 10 percent acetic acid. You must keep the fabric soaked until the stain disappears. While vinegar is safe for many fabrics, if the dyes in the colors change where you applied vinegar, immediately rinse the stain with water and apply ammonia. If you washed with ammonia, and you notice color fading, apply small amounts of vinegar after rinsing with water, to restore the color changes caused by ammonia.
Types of Stains
Vinegar can remove red ink and dye stains, fruit and beverage stains, and old perspiration stains, which is why it can also fade certain colors in fabrics. To remove dye and red ink stains from clothing, soak the item in a quart of warm water with 1 tablespoon of white vinegar; for fruit and beverage stains, add 2 teaspoons of laundry detergent. Pretreat old perspiration stains with a direct application of vinegar. Let the items steep for about 30 minutes. Only use white vinegar, as colored vinegars can actually stain fabrics.