Grinding meat, often scraps and leftovers, until it became creamy and then stuffing it into animal casings, often intestines, was a common method for ensuring longer preservation. In Germany, sausages, especially made of pork, became so popular because this method allowed them to be stored even in extremely low temperatures during the winter when food was scarce. That’s why, in warmer countries, they never reached such popularity. Food historian Bruce Craig, in his book Hot Dog: A Global History, traces this method of food preservation back to the Paleolithic era, about 20,000 years ago, by primitive humans.