There are four varieties of commercially viable coffee: Arabica, Liberica, Excelsa, and Robusta. Growers predominantly plant the Arabica species. Although less popular, Robusta tastes slightly more bitter and contains more caffeine.

In 1511, leaders in Mecca believed coffee stimulated radical thinking and outlawed the drink. In 1524, the leaders overturned that order, and people could drink coffee again.

Decaffeinated coffee is not caffeine-free. Studies from the National Institute of Health (US) have shown that virtually all decaf coffee types contain caffeine. A 236-ml (8-oz) cup of decaf coffee contains up to 7 mg of caffeine, whereas a regular cup provided 70-140 mg.

The earliest credible evidence of coffee-drinking as the modern beverage appeared in modern-day Yemen. In the middle of the 15th century in Sufi shrines where coffee seeds were first roasted and brewed for drinking. The Yemenis procured the coffee beans from the Ethiopian Highlands.

According to Guinness World Records, the largest iced coffee is 14,228.1 liters and was created by Caffé Bene (South Korea), in Yangju, South Korea, on 17 July 2014. They poured iced black Americano on the giant cup that measured 3.3 meters tall and 2.62 meters wide.

According to WorldAtlas, Canada is the only non-European country to make its top ten list of coffee consumers. The United States at a distant 25 on the list.