The white grape variety (also Freiburg 993-60) is a new breeding between Seyve-Villard 5276 (Seyval Blanc) x (Riesling x Pinot Gris). It contains genes from Vitis lincecumii, Vitis rupestris and Vitis vinifera. The hybrid was crossed in 1960 by Dr. Johannes Zimmermann (1907-1998) at the State Viticultural Institute in Freiburg (Baden-Württemberg). The name is derived from the district Merzhausen in Freiburg, where the institute owns several experimental vineyards. It was a crossing partner of the new varieties Baron, Bronner, Cabernet Cantor, Cabernet Carbon, Cabernet Carol, Cabernet Cortis, Calastra, Helios, Monarch, Prior, Rinot, Solaris. This late-maturing, high-yielding and frost-hardy vine is resistant to both types of powdery mildew and is therefore considered a PIWI variety. It yields white wines with a fruity aroma. In 2018, four hectares of vines were reported in Germany (D-STATIS); a small stand is also said to exist in Belgium.