What is Sturm? Visit Stammerdorf this weekend to find out.

Seconding the recommendation, but be warned that it is much stronger than it tastes.

Yup, it's hooch made with grapes.

The best comparison I can make to it is good-quality non-industrial alcoholic cider - the kind of stuff that it's sadly hard to get in London.

I like to compare it to palm wine in Ghana as both are newly fermented, bubbly and strong. In Ghana, the root of the palm tree is tapped and the palm wine comes out strong. As the day goes on, the drink gets stronger as it sits. Sturm is so new that a good one will have visible bubbling in the bottle - like palm wine, only minus the bugs.

Sturm is grape juice during the process of fermentation, i.e. the conversion of sugar into alcohol releasing carbon dioxide. Starting from an alcohol content of 1% the designation as grape juice ("Süßmost") has to be replaced by Sturm, according to Austrian law. Mostly Sturm is served when the alcohol content is 4% and up.

The sugar content and the carbon dioxide both foster the intake of alcohol into the blood. Therefore Sturm is perceived as being stronger as other drinks having a similar alcohol content.

After the end of the fermentation, but before further processing to make wine, the result is called "Staubiger" (dusty) because of its white opaque color, having an alcohol content of 9 to 14%.

I really enjoyed Sturm when I was in Vienna years ago. You can also get it in some wine-growing parts of Germany where it's called by a few names, including "Federwiesser" (regardless of color) and is often eaten with Onion tart, although the German version is less strong, between 4-6%. I know it's made in some parts of Italy as well.

I'll have to come back for this fest next year!

Sounds wonderful!