This is a question I get a lot, and it deserves a long answer. I wish I knew a little more about your wash habits. Since your whites have yellowed over time that could indicate a long term cleaning issue. Here are some factors that affect cleaning and whitening that you may be able to change and see better results.
- Detergent choice—Make sure you are using a good detergent that contains brighteners and enzymes in addition to surfactants and builders. Review the ingredient list—better detergents often list the purpose of the ingredients. Plus, the better the detergent, the better the improvement in performance when you add bleach.
- Use the correct amount of detergent—Under using detergent will result in poor performance, especially if you wash heavily soiled items or extra-large loads, or if you have hard water. That’s when you actually need to add extra!
- Choose a “hot” wash temperature—The higher the wash temperature, the better the cleaning.
- Don’t overload the washer—Clothes need to circulate/tumble freely through the wash water for optimum cleaning.
- Use the correct amount of bleach—That’s ¾ cup for a regular load, and 1 ¼ cup for an extra-large or heavily soiled load. Perhaps your clothes washer has a bleach dispenser that limits the amount of bleach you can add to 1/3 cup. In that case, you can experiment with smaller loads, and fill the dispenser to the “max fill” line.
It’s important to note that there are also a few situations when using Clorox® Regular Bleach2 can cause whites to yellow:
- Fabric not safe for bleach—You should never bleach garments made with wool, silk, mohair, leather, and spandex. They are damaged by exposure to bleach, which can include yellowing as well as fiber deterioration.
- The fabric finish yellows—Sometimes a finish applied to the fabric/garment will react with bleach and turn yellow. Hopefully these garments are labeled “non-chlorine bleach only”.
- Concentrated bleach exposure—If cotton is exposed to undiluted or extremely concentrated bleach solutions, it can yellow.
- Poor water quality—When the household water supply contains large amounts of metals (like iron and manganese), they react with the sodium hypochlorite active in bleach to form colored materials that can deposit onto clothes. The best way to handle this problem is to install a water treatment/filtration system to remove the impurities.
Since your shirts have yellowed over time, there’s a good chance you can whiten up the shirts again (as long as the yellowing wasn’t caused by metals). Here are some techniques you could try:
- Soak the items in a solution of ¼ cup Clorox® Regular Bleach2 per gallon of water. Fully submerge for 5 minutes, then wash in hot water using detergent + ¾ cup bleach (or fill the dispenser to the max-fill line). This is ideal for dingy yellow build-up from poor cleaning over time.
- Overnight pre-soak with powdered Clorox2® Stain Fighter and Color Booster. Add 1 scoop Clorox2® to 2 gallons hot water, and stir to be sure the product dissolves. Fully submerge the items for 8 hours or overnight. Rinse the soaking solution, and then wash in hot water using detergent and additional Clorox2®. This is ideal for white shirts that contain a small amount of spandex, which should never be washed with Clorox® Regular Bleach2.
Keeping whites their best can require a bit of work, but definitely pays off! It’s always good to prevent yellowing in the first place, but hopefully these tips do the trick.