Roasting coffee at home is really quite a simple concept however there is a huge margin for error. Whether you want cheaper or fresher coffee or perhaps the opportunity to experiment with different blends home roasting will most likely take some practice to perfect. Bear in mind, when you have developed your roasting skills a quality machine such as the Jura Capresso ENA 5 will still be needed if you want quality drinks.
The general premise for home roasting coffee in the oven is simple. You will need to be able to expose the beans evenly to air that is the temperature of at least 400 degrees for 5-10 minutes. You’ll have to know the correct time to cool them down. This might seem simple but it’s often hard to determine when to halt roasting also to prevent the coffee from unevenly roasting.
To start a new roast you will need a perforated surface that is oven proof such as a normal petal like vegetable steamer. Any type of pan with small holes in the bottom will do. You need to use something perforated so that the air can flow around the beans more evenly.
Layer a thin layer of green beans on the surface of your pan or steamer (if using a vegetable steamer you can fit a thin layer of approx. 3 oz. of beans). the green bean layer should be thin but can be 2 beans thick.
Your oven needs to be preheated to 425. Once your oven is up to temp place your green beans into the oven in a central location such as the middle of the middle rack. You will need to set a timer for ten min.. If you are trying to recreate a roast that you are fond of it would be helpful at this point to have a sample of that roast handy so you can use it as a color reference.
Shortly the coffee will start to release bound moisture because of the heat and you will start to hear crackling. One or two minutes after the cracking noise starts it is time to check the color.
Make sure to only open the oven only long enough to view the shade of the beans, believe me when I say that beans that are roasting smoke quite a bit and don’t smell like you would think. Every few minutes you’ll want to check the beans till they reach a shade just a little lighter that the desired shade.
The reason you want to pull the beans before they are the final color is because they will continue to cook and darken while they cool. It is a good practice to put your hot beans in a well ventilated area to cool so the smell dissapates.
Don’t worry if your beans look a bit uneven or darker in spots than you were trying for. Your home roast will still taste better than any stale grocery store bought bean that is available.
I roast beans around once every week or so and after they’ve had ample time to cool I load them right into my Jura Capresso ENA espresso machine to enjoy (I own the ena 5 cherry red…it’s so cool).