Carol Kuen couldn't figure out why her dishwasher wasn't cleaning her dishes very well, and they were turning filmy.
She said, "I tried loading the dishwasher differently. I tried different detergent. I tried different rinse aids."
When Consumer Reports evaluated detergents last year, testers found some left a white film on glassware. Consumers complained too, so some manufacturers reformulated their phosphate-free detergents.
Bob Markovich with Consumer Reports explained, "We developed a tough hard-water test to evaluate these detergents. In hard water, glassware is likelier to develop a film."
They also found aluminum may discolor. Testers loaded a dishwasher with clear plates and with small aluminum sheets that stand in for pots and trays. They added detergent and repeated this test 20 times.
To see how well the detergents clean away food, Consumer Reports performs another tough test. A messy mix of 17 ingredients, including peanut butter and eggs, is applied to plates and then baked on.
"Some of the worst-performing detergents left food on the plates," Markovich said.
The lowest-rated detergent was Green Mission Organic Dishwasher Gel from Whole Foods. But Cascade Complete with Dawn Actionpacs was a clear standout. Great Value Powder Pacs from Walmart was close behind and costs far less. Both do a very good job cleaning dishes, and they don't leave a filmy buildup.
In addition to choosing a good detergent, Consumer Reports says there are a number of things you can do to get your dishes cleaner, including using a rinse agent, facing the dirty side of the dishes toward the water jets and separating your flatware.