When Singapore became a British colony in the early 1800s many of the first immigrants were wealthy Chinese. They were mainly skilled craftsman or experienced merchants. As they established homesteads on the island city-state they were recruiting from their pre-established homeland networks while developing industries and staffing them. In 1858, the British setup a treaty port in Hainan after the Opium wars. With the Hainanese having a relationship with the British who also established the colony in Singapore they were granted positions and passage that gave them means to also immigrate to Singapore.
Being latecomers to the new city-state the Hainanese were relegated to jobs in the service industry. While the work was labor intensive and the pay was minimal, serving in this industry allowed the Hainanese to work alongside western chefs and learn a lot about British food culture…including coffee!
With the coffee being imported as seafaring cargo at a time before grain-pro bags, the coffee lost a lot of its natural flavors and gained some unnatural ones on the voyage.
In order to mitigate the taints and add something desirable for many of the coffee drinking westerners the coffee shops began roasting their coffee with butter and sugar. Since those who were doing the roasting were mainly Hainanese migrant workers the coffee quickly became known as Hainanese coffee. It is a very dark oily coffee.
The language of the Hainanese is not Mandarin or Cantonese. It is a conglomerate of Malay/Hokkien/Fujian and that conglomerate led to what is today called Kopi Tiam. Kopi is Malay for ‘coffee’ and Tiam is Hokkien for ‘shop’.
Kopitiams became such a socially enjoyed part of the culture that you can find these shops all over Singapore, Malaysia, and Hainan!