With coldwater detergents on the market, people often wonder if washing in warm or hot water is necessary anymore.
My laundry research experience has always shown that when holding all other variables constant, increasing water temperature improves stain/soil removal and cleaning. Overall laundry performance always goes from (best) HOT > WARM > COLD (poorest).
That’s why I always recommend using the warmest water listed on the fabric care label. Detergent manufacturers have some flexibility in changing formula ingredients to improve performance under specific conditions. However, there is no way for these chemical changes to make up for the decrease in performance when dropping the wash temperature. In fact, laundry tests that I ran showed using coldwater detergent in warm water gave significantly better performance than when used in cold water. This is true with all detergents I have tested.
Due to the large amount of oily components in body soil, one should strongly consider washing in hot water to get the best removal possible. But if you really want to use cold water for white bleach-safe laundry, be sure to add Clorox® Disinfecting Bleach along with the detergent to improve the detergent performance. Keep in mind that if you add bleach and increase the water temperature, you’ll get even better results, though. In fact, adding the appropriate laundry additive along with detergent is a great way to improve any detergent’s performance. There are other ways to help a coldwater detergent perform acceptably in cold water: include a presoak, increase the length of the wash cycle, and wash smaller loads all could help.