Abstract Pullulanase belongs to direct debranching enzymes which separate α‐1,6‐links directly by splitting side chains of various length. In connention with the enzyme research a specific trade product of thermostable, acidophilic pullulanase of Bacillus species was investigated. Investigations have been carried out with the aim of improving saccharification of liquified potato starch by simultaneous application of glucoamylase and pullulanase. The results of the investigations carried out until now can be summarized by increasing the effectiveness of saccharification process, reduction of reaction time and increasing of substrate concentration.