Lets compare the heat retention of a food thermos vs. a beverage thermos. As you probably know a sphere is the geometrical shape which has the least surface area to volume ratio. A food thermos is typically lower and wider than a beverage thermos, making it closer in shape to a sphere. Meaning, if it has the same volume as a beverage thermos it has less surface area. And less surface means less heat loss. But it's not that simple with a thermos. Since the cap is less insulated than the walls, and a food thermos has a bigger (and thinner) cap than a beverage thermos. Meaning the food thermos has more area which is less insulated than the beverage thermos. For this experiment I got the most durable thermoses I could find, one Thermos Stainless King 16 oz. Food Thermos and one Thermos Stainless King 16 oz. Beverage Thermos . (Also available in bigger sizes .) According to the manufacturer they both keep the content hot for 12 hours and cold for 24 hours. Let's see if tha...