Fewer E. coli on steel surface

The Hospitality Institute of Technology and Management, a Minnesota-based company that provides consulting services to the food industry, tested several different countertop materials for their response to cleaning. The materials included laminate, wood, tile, concrete, stainless steel and granite. S30400 stainless steel with a number 4 finish was judged the safest of them all, following washing, rinsing and sanitization.

The study took place in two stages. First, the researchers inoculated each of six countertops with E. coli bacteria. The countertops were then washed with soap and water, rinsed and swabbed for remaining bacteria. Next, the countertops were wiped with a 10% solution of vinegar and allowed to dry. A second swab and culture determined how many of the E. coli were destroyed by the vinegar.

While the granite countertop showed the greatest response to the wash and rinse, stainless steel was the cleanest after the vinegar was applied. Granite also responded well to vinegar, but, over time, the vinegar would degrade the countertop’s finish.

The researchers concluded that most of the other countertops would become harder to clean as their protective coating wears down. But the stainless steel countertop would maintain its cleanabiltity because it is more resistant to scratching and doesn’t warp. Laminate and tile were the least responsive to washing, but the laminate counts improved significantly after vinegar was applied. Wood fared poorly after both treatments. The study concluded that interior designers should consider food safety when choosing countertops for residential kitchens. Stainless steel has long been the standard in commercial kitchens, but wood and laminate products are more common in the home.

— The preceeding is an excerpt from Nickel, a publication of the Nickel Development Institute, based in Toronto, Ont.