This article shares the fun of personally roasting coffee at home—though some details may now be a bit outdated—and Y5Cafe welcomes updated experiences from readers!
Previously, Thịnh Còi posted an article on “Growing Coffee at Home.” Now those tiny potted coffee plants have borne fruit, and what could be more delightful for a true coffee lover than roasting beans you grew yourself to brew a “homegrown” cup.
Everyone knows Vietnam is the world’s second-largest coffee exporter and proudly produces some of the best coffee globally. Yet very few farmers—the very people who built Vietnam’s coffee reputation—have actually tasted coffee made from beans they personally grew.
Thịnh believes that whatever you produce, you should be the first to enjoy and appreciate its true value. So today he decided to roast a batch himself.
Ingredients
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A pan (any kind will do, preferably one that’s already been retired from kitchen duty—after roasting, the dark coffee oils will stain the bottom).
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A bit of fish sauce.
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A little butter (to help the coffee absorb flavor, prevent clogging of the filter, preserve aroma, avoid “oiling up,” and add a silky texture).
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A splash of liquor.
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Sugar.
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And, of course, green coffee beans.
The process was wonderful—from stirring the beans over the stove to blending them into powder in a Philips blender to create the final product. It would have been almost perfect if, after brewing a pure Cầu Đất Mocha, he hadn’t jokingly declared: “Terrible!”
Learning from this, Thịnh decided to write this guide so anyone trying home roasting can follow proper technique. Roasting is a crucial step in coffee processing.
Roasting Technique
Roast coffee at 190–230 °C (374–446 °F) for about 18–25 minutes (modern roasters can reduce this to only about 8 minutes).
During roasting, coffee beans lose 14–23% of their weight as moisture evaporates but expand 40–60% in volume. Complex biochemical reactions occur—known as pyrolysis or simply “Pyro”—forming coffee oils, complex sugars (oligosaccharides), unsaturated fats, and the signature coffee aroma.
By the end of roasting, the beans become plump and shiny. Some starches convert to sugar and caramelize, giving coffee its rich brown color.
When roasting is complete, the beans must be cooled quickly to preserve their aroma. Typically, the hot beans are spread onto a large aluminum tray and cooled with an electric fan.
The Art of Roasting
Coffee roasting truly is an art. The roaster must draw out the natural characteristics of each coffee variety, shaped by its genetics and the soil where it grew.
A skilled roaster listens for the crack of the beans, smells the evolving aroma, and judges the exact color needed. If the beans are under-roasted, the brewed coffee will lack depth; over-roast them and you’ll end up with a bitter, burnt cup.
Therefore, the roaster must carefully balance time and heat to achieve the desired profile.
This piece reflects the personal impressions and hands-on practice of a passionate coffee enthusiast and will surely differ from professional or strictly scientific roasting techniques. Thịnh warmly invites experienced roasters to share their knowledge and encourages everyone to try roasting their own coffee and share the joy of a truly self-made cup.