Aoltbeer, also known as Münstersch Alt, is the historic sour beer of the city of Münster, Westphalia. It is a mixed-fermented, barrel-aged beer with a vinous character.

The sourness comes from Kemker's own house culture of wild yeasts and lactic acid bacteria. A relationship to Belgian Geuze and Berliner Weisse cannot be denied.

This Aoltbeer is a single barrique which matured undisturbed for four years. The result is a beer with a pronounced acidity, layered with delicate notes of oak leaves and elderflowers. A great companion for fresh cheese, leek and black pepper.

Bottled in March 2026, 200 bottles.