May wine, also known as Maiwein, Maibowle and Waldmeisterbowle, is the name of a German beverage that uses aromatized wine as a base (see sangría). Just as Wassail is, or was, served during winter celebrations, May wine is served in the spring, traditionally on the May Day holiday.
The base is made by taking sweet woodruff (Galium odoratum, sometimes called Asperula odorata, known in Germany as Waldmeister), a fragrant creeping herb that grows in the forests of Northern Europe, and steeping it in a white German wine. Since woodruff is very slightly poisonous, some common sense should be applied in its use; 3 grammes of woodruff per litre of may wine is completely safe.
Flavoring ingredients such as brandy, sparkling wine (or carbonated water) and sugar may also be added to the mixture to create a punch -- hence another common name for the beverage is the Maibowle (May-bowl). Since strawberries are in season at that time of year, they are often floated in the bowl and in the drinking vessels being used.
May wine can also refer to a commercially bottled beverage meant to simulate the drink as described above. It will invariably consist of the white-wine base infused with the woodruff herb; individual variations might include strawberry flavoring, or fermentation techniques to make it lightly sparkling. It is produced in German culture regions of the United States such as Frankenmuth, Michigan. Commercial May wine produced in Germany itself is made with artificial flavoring and coloring agents since the 1980s, as the use of woodruff in commercial preparations was made illegal in Germany.
The Council of the European Communities legally defines Maiwein thus: