GRUENFELD, JUDAH (1837–1907), Hungarian rabbi. Gruenfeld was born in Satoraljaujhely. He was one of the most important pupils of Abraham Judah Ha-Kohen Schwartz, rabbi of Beregszasz-Mad, and like his teacher frequented the court of the Ḥasidic rabbi of Zanz. He lived for a time in Huszt, where Moses *Schick often consulted him on important problems. In 1883 he was appointed rabbi of Büdszentmihály, serving there until his death. His writings were not collected, but a substantial part of them were published by Joseph Schwartz in Va-Yelakket Yosef (1899–1917). Twenty-six important responsa were published in Responsa Maharshag (1961) by his son simeon (1881–1930), who served first as dayyan of Munkacs and then succeeded his father at Büdszentmihály. Simeon was the author of Responsa Maharshag, Pt. 1 (1931) on both Oraḥ Ḥayyim and Yoreh De'ah, Pt. 2 (1939) on Oraḥ Ḥayyim alone. In 1961 the work was republished in Jerusalem with his additional responsa on Ḥoshen Mishpat and Even ha-Ezer. His responsa are distinguished by their clarity, their penetration, and their great erudition. He also wrote Zehav Sheva (1933) on the Pentateuch. He left more than 2,000 responsa in manuscript, novellae on several tractates, a large work on the halakhot of mikva'ot, and a work on ta'arovot (mixtures containing forbidden food). It is doubtful if these works have survived.