Hi Tanya, thanks for this question.
Roasting coffee at home is a fun, and rewarding experience and only requires minimal equipment. In addition, it only requires a basic understanding of the roasting process to get started.
In terms of equipment, you'll need a roaster, green coffee beans, and -optionally- an infrared thermometer.
Regarding the process, the first step is to choose the green coffee beans that you would like to roast. It's important to select high-quality green coffee beans. You can find these beans online or from local farmers or cooperatives, depending on where you are.
Next, you will need to select green coffee. You can search online for a guide on green coffee defects, but the most common ones are evident. Pierced, bitten, or broken green coffee beans aren't suitable for roasting. If you find dirt, tiny sticks, or any natural residues, discard them too.
Once you pick your best green coffee beans, you can proceed to roast. I have used a skillet and a frying pan to roast green coffee. Many people suggest using a popcorn popper, but I can't tell for sure how good it works.
I learned to use a thermometer for stovetop coffee roasting. It helps to understand your roasting profile a bit more and develop a more repeatable process.
Still, listening is crucial. Roasting with a skillet is better than using an oven because you can stir and move the coffee beans. That helps to obtain a more uniform result.
Make sure to keep stirring the beans continuously throughout the roasting process to prevent them from burning. If you're roasting with a frying pan on the stovetop, it's best to watch them and adjust the heat as needed.
The roasting process will take more than 10 minutes, so be patient!
Once you listen to the first crack, it is crucial to monitor the temperature. If you don't have an infrared thermometer, it's inexpensive. But, if you don't want to buy one, check the color of the coffee beans.
The next sign after the first crack is that the chaff loosens. Here it's better to stir vigorously, to release as much chaff as possible. The temperature before finishing should be a bit above 200 °C or 400 °F. Below that temperature, it's more likely to get a poor result. Still, getting a roasting temperature above 230° C or more than 450 °F might likely burn your coffee beans. So, it's crucial to pay attention to this. If you listen a second crack, you'll have a pretty dark roast, and you can stop for sure.
After roasting, allow the coffee beans to cool for a few hours before storing.
You can use special bags to store roasted coffee. It works better this way because coffee needs to degas for a few days before using it. Usually, three days is enough, although I have noticed that some coffee beans are at their best between 1 and 2 weeks after roasting.
Are you ready to roast coffee at home? Please let me know if you have further questions.