From 1779 to 1786 he was apprenticed to his uncle, August Grenser, a Dresden instrument maker, and after his apprenticeship he continued to work in August's shop, taking it over himself in 1796. Heinrich Grenser invented an early form of bass clarinet in 1793, and may have been the inventor of the alto clarinet, beginning production in 1808.
^Young, Phillip T. (May 1978). "Inventory of Instruments: J. H. Eichentopf, Poerschman, Sattler, A. and H. Grenser, Grundmann". The Galpin Society Journal (The Galpin Society Journal, Vol. 31) 31: 100–134. doi:10.2307/841193. JSTOR841193.