Dish detergents get tough.(dishwasher detergents)(Evaluation)

Manufacturers are usually eager to tout an ingredient intended to boost a product's performance. But the makers of dishwasher detergents seem shy. Though more and more dishwasher detergents contain enzymes, you'd be hard-pressed to tell the enzyme-detergent packages from the rest. That's true even though we've found that the new enzyme-containing formulas tend to improve cleaning significantly.

Enzymes in dishwasher detergents aren't new, but they are a growing trend. We discovered their dirt-busting ability by testing 24 dishwasher detergents in all their forms: powders, liquid gels, and tablets (the newest form). While enzymes in detergents don't ensure excellence--two of the eight enzyme detergents we tested were relative washouts at cleaning--the best cleaned far better than the rest of the field. What's more, dishwashers performed so much better with an enzyme product than with a regular one that we had to adjust our dishwasher Ratings system (see the report on page 40).

Yet for most of the products we tested, the word "enzymes" is buried in the label's small print. Do manufacturers think consumers would have a tough time digesting the word? That's not how a spokeswoman for Procter & Gamble, makers of Cascade, puts it. "When we talk about our products with consumers, they are not interested in the chemistry. They're interested in what benefits it has for them."

DISHING OUT THE DIRT

To test the detergents' mettle, we coated clear glass plates with a carefully concocted, tough-to-clean mess. We zapped the soiled plates in a microwave oven, aged them for several hours, then washed them in four new, same-model dishwashers fed with hard water (the norm in much of the country). We used each detergent's recommended dose for normal loads (usually, that meant filling a machine's dispenser cups with powder or liquid, or using one tablet).

The best cleaners were six enzyme-based products (two from Electrasol, four from Cascade). The enzymes in those detergents apparently do what they're meant to do, that is, break down food particles so the other ingredients can remove them. Most of the other products did an adequate job, but a few were not much better than plain water.

Along with removing soil, a detergent should keep soil from resettling on dishes. Most of the top cleaners also did well on that score. So did some poor cleaners--but they removed less soil in the first place, so there was less to redeposit. Water spots are another bane; best at preventing them were Electrasol Dual Action Tabs with Baking Soda and Cascade Pure Rinse Formula Gel.