His first business venture was the establishment of a fireworks factory in the 1930s under the brand Leo, located in Rembang, Central Java. Leo became a leading fireworks brand in Indonesia.[2][3]
Sometime in 1938, his factory exploded, killing and injuring some of its workers. Nonetheless, his factory was rebuilt and continued producing fireworks.[4]
In 1951, Oei Wie Gwan purchased a small business named Djarum Gramophon, which literally translates to "gramophone needle".[6]
The company was established on 21 April 1951 on Bitingan Kudus Street with 10 employees. The small-time venture soon took off.[7]
Kretek became Oei Wie Gwan's business of choice following the closure of his fireworks business. Under the PT Djarum brand, tobacco and cloves, were blended in cigarettes.[citation needed]