A perpetual stew, also known as forever soup, hunter’s pot, or hunter’s stew, is a pot into which foodstuffs are placed and cooked, continuously. The pot is never or rarely emptied all the way, and ingredients and liquid are replenished as necessary. Such foods can continue cooking for decades or longer if properly maintained. The concept is often a common element in descriptions of medieval inns.
Foods prepared in a perpetual stew have been described as being flavorful due to the manner in which the ingredients blend together. Various ingredients can be used in a perpetual stew such as root vegetables, tubers (potatoes, yams, etc.), and various meats.
I’d say you can drink a soup but you can’t easily drink a stew.
To be more specific: you can drink the liquid part of the soup. You get soup with big chunks of meat and veg in it which doesn’t make it a stew even though you wouldn’t be able to drink it.