Noticing the presence of colourless crystals in a glass of white wine was the starting point for some simple experiments to identify their chemical nature. The author did not succeed in identifying the chemical, but learned about the presence of an acid-base indicator. In retrospect, he was aware of the special chemical way he had considered the crystals and the way to solve the problem on the basis of the chemical properties of the suspected substance. A teaching goal in chemistry education can be to motivate students to look at the world in this "chemicalised" way. Even if not completely successful on this occasion, the exercise showed that scientific practical work can be attempted in the home environment. (Contains 2 figures and 1 table.)