In 1474 most of Nowy Korczyn burned in a fire, after which the town was released from its tax duties for 12 years. In 1549, King Zygmunt August funded a hospital, and at that time, Korczyn was a major beer producer, with 19 small breweries. Furthermore, it had waterworks and baths, built in 1578 with permission of King Stefan Batory. Eight times a year grain markets were organized, and the grain purchased in Nowy Korczyn was transported along the Vistula to Gdańsk. Korczyn had a number of granaries, in 1566 a new town hall was built, and in 1568 a canal was completed, which connected the man-made lake "Czartoria" with the Nida river. In 1589, a weapon manufacturer was opened in Nowy Korczyn, producing gunpowder, cannons and rifles.