Beautiful drinking vessels known as kuksa are carved from burls found growing on birch trees. Burls are a kind of growth on the tree—a woody lump that starts growing when trees undergo some form of stress such as an injury, virus or fungus.
To create a traditional kuksa, you must first remove the burl with an axe and a saw, then begin carving with a specialised hooked knife that allows you to dig out a bowl shape while following the natural curvature and circular grain of the wood. This circular grain of growth makes the kuksa very strong and is what makes it so desirable for wood-carvers. The finest examples have decorated, intricately carved pieces of reindeer antler on their handles.
To look after a kuksa properly, one must add oil to the outside occasionally while also making sure to use it regularly for drinking coffee, water and a good smokey whiskey. Together, these three create a lovely dark patina on the wood! And remember to never put milk in your kuksa cup—it’s not good for the wood!