Experiments with Stone Age glue

Birch pitch is considered to be the oldest superglue in history. It was already being used 45,000 years ago as an extremely effective all-purpose adhesive. The hunter Ötzi from the late Neolithic period, for example, used it to fix his arrowheads. The ancient Greeks, Romans and the Middle Ages were also familiar with the black miracle substance made from white birch bark. Throughout human history, it has been used to fix the blades of weapons and tools, to repair broken ceramics and even to seal boats and canoes.

The glue is not obtained from the resin or sap of the birch tree, but from the leathery bark. It is a black, smoky, lumpy mass that becomes flexible and malleable under heat. Once cooled, birch pitch is almost as sticky as modern two-component glue! Birch pitch owes its sticky properties to its high proportion of resin acids and highly volatile aromatic compounds. During production, a polymerization reaction takes place between the molecules of the substances. Low-molecular compounds thus become a polymer and the very first plastic known to mankind.

We have long been amazed by the capabilities of natural materials. Inspired by the idea of reconstructing ancient craftsmanship, we began to collect birch bark. We later placed the bark in a fireproof container and put it on the campfire. After a while, the liquid pitch ran through a hole in the bottom of the bucket into a glass under the fireplace. We sweetened the waiting time of an hour with a delicious barbecue. We can only recommend trying it!

We were able to collect a small amount of glue from our very first attempt. The success of our experiment inspired us to think about modern applications for the (at least) Stone Age glue. Could we use it to seal vases made of wood or cork? Repair the soles of shoes? Hang up posters? Fix bicycle tubes and inflatable boats? Make super-strong chewing gum? In any case, we remain open to future experiments and applications.