The traditional mead-like drink consumed on Vappu in Finland is sima.
Sima is a lightly fermented Finnish beverage traditionally made with water, honey, sugar, lemon, and a small amount of yeast. Modern recipes usually rely more heavily on white or brown sugar than honey, so the drink is often closer to a lightly alcoholic sugar wine than to ancient-style mead.
Its short fermentation creates gentle carbonation and usually leaves the drink with very little alcohol. Raisins are commonly added to bottles: they swell and rise as fermentation progresses, providing a traditional visual sign that the sima is ready. Homemade sima is normally served chilled.
Sima is strongly associated with Vappu, Finland’s May Day and Walpurgis celebrations, and is often served with munkki doughnuts or tippaleipä funnel cakes. It should not be confused with kilju, a stronger homemade sugar-based alcoholic drink, or sahti, a traditional Finnish beer.