Viscous bubble solution - interesting wrinkles

Accidental discovery! A few weeks ago I tried some homemade bubble recipes and made a bubble solution. After a fun afternoon the solution laid forgotten.

I looked at it yesterday and the surface is very interesting. The solution become so viscous and the surface carries a lot of wrinkles. The wrinkles remind me of making soup or heating milk in a pot. When it's almost done there's always a thin layer of wrinkled surface of hot soup/milk. Good to know that it could be re-produced a more permanent way! Would be fun to inject some air bubbles...