This is a demo where I place a birch bark bowl full of ice cold water fresh from the creek directly onto campfire coals to see how well this method can be used for cooking. It proved to be en excellent method for soups or other high liquid recipes that require longer term cooking. Ideal would be to let the bowl heat up as hot as it’s going to get and then use a hot rock or two in there to boil as long as you need high heat to kill any bacteria. After that then just let the embers do their work for as long as you want to tenderize and finish cooking. Another option would be to “sew” some sticks (with willow cordage or….)to the diameter of a small piece of Birch Bark to use as a lid. The sticks would be to keep the bark from curling. I believe the bowl would boil on it’s own then.