An Etymological Dictionary of the German Language/Hebel
Hebel, m., ‘lever, yeast,’ first occurs in early ModHG. in the sense of ‘lever’; comp. MidHG. hębel, hęvel, OHG. hęvilo, m., ‘yeast’ (as a means of causing a thing to rise); v, f, as the older form, was supplanted by connecting the word with heben.