Wondering how long something's been in the fridge? Has it been days or months? The reason we refrigerate is to slow bacterial growth -- and the magic number for food safety is 40 F. Above this temperature, bacteria grows rapidly. There are two types that affect us. One is spoilage that deteriorates and ruins food; the other is pathogenic, which is far worse (because whereas food looks and smells all right, it could make you sick and even be dangerous). Food stored at 35-40 F lasts longest. But how do you know how long is OK? As rule of thumb, store cooked leftovers no more than four days. Raw poultry and fresh meats should be stored just one to two days maximum. To keep track of what's up front (and way in back), use a marking pen masking tape and post-it notes. Date everything you open or put away. For more info on food storage times check FSIS.USDA.Gov -- under "refrigeration and food safety." For more tips, visit our Web site at onthehouse.com. And that's the On The House tip for today.