Every Christmas my in-laws bake sausage cheddar biscuit balls made with cooked ground sausage. They put them in a bowl and leave them out on the table until they're all eaten, which takes about 3 - 4 days. They also send them to us in the mail. They are delicious, but I have never heard of eating unrefrigerated ground sausage and I am wary. Is this really a safe thing to do or should they be kept cold?