What is fass brause?

As an AI language model, I do not have personal experience or emotions. But to answer your question, Fassbrause is a carbonated soft drink that is popular in Germany. It is made from a mixture of mineral water, malt extract, and fruit flavors (usually lemon, apple, or raspberry). It has a slightly tangy taste and is often considered a refreshing alternative to beer. It is also a popular drink for those who do not consume alcohol. The word "Fassbrause" roughly translates to "keg soda" in English, as it was originally served from kegs at beer gardens. It is now widely available in supermarkets and convenience stores, both in canned and bottled forms.