It is a substitute good (ersatz) for true rum which is produced from sugarcane mainly in the Caribbean and Latin America.
[1] Tuzemský is produced from potatoes or sugar beets, diluted and flavoured by various rum essences.
In the 19th century similar substitutes were produced throughout the crown lands of the Austro-Hungarian monarchy, which had no access to tropical colonies; they were named Inländer-Rum (the best-known example of this is probably Stroh in Austria), Domači or Čajni (Croatia) etc.
EU regulations allow the name "rum" to be applied only to products made from sugarcane.
As a result, from 1 January 2003, this product is sold under other names like "Tuzemák" or "Tuzemský".