Achard revived the discovery by Andreas Sigismund Marggrafs in 1747 that sugar beets contained sugar, and devised a process to produce sugar from sugar beets. In March, 1802, with the support of king Friedrich Wilhelm III, he opened the first sugar beet refinery in Wohlau-Cunern, Silesia, Prussia. It was a destroyed a few years later by the French.
In 1776 he was elected a member of the Royal Academy of Sciences at Berlin and later went on to become the director of the German Academy of Sciences.
Among his works is the four volume "Lectures on Experimental Philosophy" (1792).