Cotton can begin to turn yellow due to factors such as contact with body oils, washing with coloured items, time, or washing in hard water. In addition, contact with staining agents such as urine, food or beverages can turn cotton yellow. Fortunately, yellow stains can be removed with quick, easy steps.
Check the labels on your cotton fabric in order to see the highest heat the product can be washed in.
Spray the yellowed area with a vinegar/water mixture and allow it to sit for about an hour. Scrub the area with a soft sponge or towel.
Soak the fabric with a pre-soak detergent. Allow it to sit for a full 24 hours. This will help to break down materials that are deep inside of the fabric and will help to clean it later.
Fill your washer with the hottest water that your cotton item can handle. Use more detergent than normal (about 1/2 to twice as much). Add four to five drops of mild dish detergent.
Add colour-safe bleach to the washer after the washer has completely filled up.
Dry the item by hanging outside or by drying on low heat in the dryer.