What causes redeposition in laundry?
A very common and irritating problem in laundry is the redeposition of soil onto fabrics or garments, giving white fabrics an off-white appearance or dulling colored fabrics. This problem occurs when the soil is not flushed fast enough.
Redeposition can be caused by several factors. The three most common causes are insufficient detergent, ineffective detergent, and overloading of the washer. To check for redeposition, simply wet a small area of the affected fabric with a relatively strong detergent solution, rub between your fingers, and rinse. If the off-color appearance is caused by redeposition soil, the area will appear lighter because the soil has been removed.
Another cause of redeposition is incomplete rinsing, usually the result of deleted rinses from the wash formula or low-rinse bath levels.