Whether you're using dishwashing liquid for a few pots and pans or for delicate laundry items, you want it to be effective, mild for your skin and cheap. To see which liquids were best, Consumer Reports tested 20 products -- including familiar brands like Ajax, Palmolive, Dawn and Ivory; supermarket brands; "green" brands; and "antibacterial" brands.
Cleaning power was gauged by using shortening -- a reasonable stand-in for the remains of dinner that cling to your dishes. The more shortening the liquids removed during 30 minutes of exposure (without wiping) in the lab procedure, the more effectively they'll clean greasy food off your dishes.
Consumer Reports tested with both soft water and hard, and found that most of the products cleaned significantly better in hard water. The ratings were based on hard- and soft-water cleaning power, suds stability and mildness.
The absence of suds in the dishpan doesn't necessarily mean the dishwater can't clean anymore. Even so, testers down-rated the eight products whose suds were fastest to disappear, because you might be tempted to unnecessarily add more.
Dishwashing liquids are all relatively mild detergents, but, in a lab test for mildness that uses synthetic human skin, testers found some differences. By a small margin, Seventh Generation was the mildest liquid tested. Dawn Original, Sunlight Fresh Lemon Scent, and Amway Dish Drops were the least mild; you might want to avoid those three if your skin is easily irritated.
The best brands carry familiar names -- Dawn (both Free and Original Scent received an Excellent rating ), Palmolive and Joy. But Ajax, Sunlight and Dazzle (from Kmart) were all very good, and a bit cheaper than the brands at the top of the ratings. In contrast, the Amway liquid, an undistinguished cleaner, was by far the most expensive.
The Ivory listed in the ratings has since been reformulated; check-tests in soft water indicate that the new formula should perform about the same as the old.
High-priced Seventh Generation and Ecover are touted for their lack of petroleum-based ingredients and other "green" qualities. Considering the minimal impact any dishwashing liquid has on the environment, the products offer no clear environmental advantage.
Besides the regular products in the ratings, Consumer Reports check-tested the new, concentrated "ultra" versions of Dawn, Dawn Free, Ivory and Joy. The concentrates come in a squat little bottle that's two-thirds the size of a standard bottle but typically sells for the same price.
When they were tested using a third less than their regular counterparts, Dawn and Dawn Free concentrates turned out to be less effective at cleaning than the regular-strength Dawns; Ivory and Joy concentrates were equal to their regular versions.