If you find a container of yogurt hiding in the back of your refrigerator and it’s past expiration, don’t toss! Put it to good use to clean any copper items you have! Skip the pricey cleaners for your cookware and utensils and such; just apply about a tablespoon of yogurt to the discolored areas. Let sit for 5 minutes, then rinse with cool water. The acids in this breakfast favorite will have dissolved the dark copper oxide stains. Your copper will gleam!