Episode Details

The whipped coffee that filled kitchens during the spring 2020 lockdowns began decades earlier with Leong Kam Hon, a shipwright in Macau whose shipyard accident left his left arm incapacitated in the late 1990s. Forced to find a new living, he opened a small shop in Coloane, first called Y Ting Coffee and later Hon Kee. In 1997 a tourist couple asked for a special coffee, and using his one good arm he beat equal parts instant coffee, sugar, and hot water into a thick paste. In 2004 actor Chow Yun-fat visited, loved it, and fans began asking for Chow Yun-fat coffee, though the menu simply called it hand-beaten coffee.

In January 2020 South Korean actor Jung Il-woo tried it in Macau on a celebrity recipe show and said it tasted like dalgona, a honeycomb toffee made by puffing melted sugar with baking soda. Weeks later the pandemic hit, and the Dalgona Coffee Challenge spread from YouTube in South Korea to TikTok by early March. The episode explains why the foam only works with instant coffee, and why older whipped drinks from India, Greece, and Italy never went viral the same way.

• Spray drying or freeze drying strips out the oils that collapse foam, leaving proteins that act as surfactants.
• Dissolved sugar thickens the bubble walls so the foam can hold even when the bowl is turned upside down.
• Whisking by hand could take 10 to 20 minutes, and the rhythmic sound and slow transformation gave the videos an ASMR pull.
• India's beaten coffee puts the paste at the bottom and pours hot milk over it, while the Greek frappe dates to 1957 and is shaken.
• Dalgona floats the foam over white milk as a separate layer, a high-contrast look built for phone screens.