Every day, as many as 2 billion cups of coffee are drunk around the world, which translates into an incredible number of almost 25 million liters of this aromatic drink. To better illustrate this, imagine that more than 7 Olympic swimming pools are filled with coffee every day. Sounds really impressive, right? Let us remember, however, that coffee is not only the liquid itself, but also coffee grounds, with which something needs to be done after preparing your favorite small black coffee. Unfortunately, in most cases they end up… in the trash. And there are plenty of interesting ideas for reusing coffee grounds!