Roasting coffee at home is easier than most people think. With a basic roaster, a bag of green coffee and about 15 minutes, you can roast coffee that is fresher than anything on a store shelf. Mexican green coffee is an ideal place to start: it is clean, sweet and forgiving, so small mistakes still taste good.
What you need
- Green coffee. Start with a washed Mexican coffee, such as our Chiapas or Veracruz lots, sold in 5 lb bags for home roasters.
- A heat source. A hot-air popcorn popper, a stovetop pan, or a dedicated home roaster all work. Dedicated roasters give the most control and the most consistent results.
- A way to cool the beans fast. Two metal colanders or a sieve and a fan.
- Good ventilation. Roasting produces smoke and chaff (the papery skin that comes off the bean). Roast near an open window, under a hood or outdoors.
The stages of a roast
- Drying. The beans turn from green to pale yellow and smell grassy, like hay. This usually takes the first 4 to 6 minutes.
- Browning. The beans turn tan, then light brown, and start to smell like toasted bread. Sugars caramelize and aromas develop.
- First crack. You will hear a crackling sound, similar to popcorn. This means the coffee is drinkable. Stopping shortly after first crack gives a light roast with more acidity and fruit.
- Development. The time after first crack. One to three more minutes gives a medium roast, where Mexican coffee shows its chocolate and caramel sweetness.
- Second crack. A quieter, faster crackle. Going into second crack produces a dark roast with more bitterness and body. For most Mexican coffees, we recommend stopping before it.
Cool quickly
As soon as you reach your target roast, cool the beans. Pour them between two colanders or stir them in front of a fan until they are cool to the touch, ideally within 2 to 4 minutes. Slow cooling keeps the beans roasting and flattens flavour.
Let the coffee rest
Freshly roasted coffee releases carbon dioxide. Store it in a container with a one-way valve or a loosely closed jar and wait at least 12 to 24 hours before brewing. For espresso, many roasters wait 5 to 7 days for a smoother shot.
Tips for roasting Mexican coffee
- Aim for a medium roast first. It brings out the chocolate, caramel and nutty notes that Mexican coffee is known for.
- Higher-grown lots, such as those from Oaxaca, are denser and can handle a little more heat early in the roast.
- Keep notes: batch size, time to first crack, total time and how it tasted. Small changes make a big difference.
Frequently asked questions
How much green coffee should I roast at once?
Follow your roaster's capacity. Popcorn poppers handle about 80 to 100 g; most home drum roasters handle 250 to 500 g.
How long does green coffee keep?
Stored cool, dry and away from light, green coffee stays fresh for many months, which is why our home roaster bags are metallized.
Where can I buy green coffee for home roasting in Canada?
We ship Mexican green coffee in 5 lb bags across Canada from Vancouver, and our bags are also available on Amazon. Shop green coffee for home roasters.