Roasting your own coffee is an age old tradition and the best possible way possible to get a great cup of coffee. Before all the fancy, and not to mention expensive coffee roasting machines appeared on the market, people roasted their coffee on wood fires in nothing more than a saucepan.
While that may not be an option for most people today, unless you are out camping, it is still possible to roast your own coffee without burning a hole in your pocket.
A popcorn popper is simply the most effortless and perhaps the cheapest method of roasting your own coffee at home. A lot of the relatively inexpensive popcorn poppers will double as coffee roasters, but there are some that will not. The trick is to know what to look. Getting corn to pop only requires around 350° F of heat, whereas roasting green coffee beans requires up to 480°.
For this reason, it is best to buy an older model; these older machines are equipped with hardier heating elements, stronger fans and motors with more wattage. Needless to say the older models will also be cheaper. This is not to say that some of the newer models will not roast coffee, you just need to look more carefully to ensure that it will achieve the required temperature needed to roast coffee.
Achieving the right temperature is critical to roasting coffee, thus being able to monitor the temperature of the chamber where coffee is being roasted helps to deliver a consistently good cup of coffee. A large number of popcorn poppers have built in thermometers, but they are not always monitoring the temperature inside the chamber.
Since these machines are built to pop corn and not roast coffee, these thermometers monitor the temperature of the element and once it reaches a certain temperature, the machine shuts off automatically, leading to a temperature drop in the chamber where beans are being roasted. These types of machines are totally inappropriate for roasting coffee beans.
Once you are able to acquire a popcorn popper that can achieve the higher temperatures uninterrupted, a minor alteration (if you are handy with tools) can help you to monitor the temperature inside the chamber. Simply drill a small hole through the side of the machine’s body and insert a candy thermometer at an angle in such a way that it ends up in the middle of the chamber but does not touch the bottom, and you are all set to roast.
Thermometers used for roasting meats will not work, as they only read temperatures to about 350° F whereas candy thermometers are capable of reading temperatures of up to 550° F. Of-course, if you are not proficient at using tools, then let time and experience be your guide to roasting the perfect cup of coffee without a thermometer.
A second thing to look for when intending to use a popcorn popper for roasting coffee is to get one with air vents on the sides of the roasting chamber and a solid bottom. Models having single grate at the bottom tend not to supply air with sufficient force to keep coffee from burning, and may become potential fire hazards during the coffee roasting process.
Another essential detail to remember when shopping for a popcorn popper which you plan to use for roasting coffee is to seek one that has a holding chamber with a depth of around four and a half inches.
A larger chamber like this will have the capacity to roast roughly 90 grams of green coffee beans (sufficient for one, ten cup pot of coffee) and yet leave sufficient space for them to expand and not shoot out of the popper.
In a smaller chamber of for example 3.5 inches, chances are that the beans will shoot out of the popper and land all over! If you do end up getting one with a smaller chamber, it will require a modification to make the chimney longer. While this is easy enough to do with an empty food can that has been cut at both ends, it is just easier to buy a popper with a larger chamber.
With the correct popcorn popper, it is possible to get an evenly roasted batch of coffee in around 4 to 8 minutes. At about a temperature of 420° F you should start to hear what sounds like very gentle fire crackling.
This is the first crack stage. If you desire mild (light roast) coffee with maximum caffeine then stop roasting at any time during this process of crackling. The color of the beans will be light to medium brown accompanied with muted smell. If you continue roasting, the crackling sounds will eventually stop.
About 5 to 6 minutes into roasting you will start hearing new sounds that will increase in frequency and be of higher pitch than the sounds heard previously. This is the second crack stage, and its start signals the medium roast stage of the coffee bean. At this point the beans are darker shade of brown and the smell is more pronounced.
Allowing the beans to roast further into the second crack stage (say thirty seconds) produces the dark roast. It is time to unplug the machine and remove the beans quickly onto to a cookie sheet or a colander and preferably move outdoors. As the coffee beans are shifted around in the colander or cookie sheet, the chaff will come off and fly all over the place (which is why it is better to do this outdoors instead of messing up the kitchen and any open adjacent rooms!)
Great care needs to be taken when cooling the beans as the cookie sheet and even the colander become really hot as they absorb the heat from the beans. It is good that the heat is removed from the beans quickly and they don’t get burned with the excessive heat they contain, but it can be bad news for your hands.
If you like the idea of roasting your own coffee beans in a popcorn popper, how about going all out and growing a coffee tree at home, so you can harvest your own green coffee beans? It’s not too far fetched, if you have the correct growing conditions.
IMPORTANT SAFETY TIP: Hence, it is important to wear some protection on your hands when carrying out this final step in roasting coffee beans. Once the beans are cooled to the point where there is no danger of them becoming over roasted from the trapped heat, they need to rest for two to five days so they can degas.
While you can make a cup of coffee immediately with your freshly roasted beans, the best taste will only be achieved after the beans are allowed to rest.
Imagine the smell of your favorite roasted coffee beans, fresh out of the popcorn machine! And then using those fresh ground beans to make your favorite coffee cake, or using that fresh espresso to make a warm coffee sauce recipe. Simply delicious!!