How to Roast Coffee Beans at Home? How to Use a Square Drum Roaster? How to Make Coffee from Raw Coffee Beans?

As coffee has become part of our daily routine, it's easy to learn comprehensive and up-to-date knowledge about all aspects of coffee through video platforms. Beyond studying brewing methods and how to taste the flavors within, many enthusiasts have developed a strong interest in coffee bean roasting.

However, many enthusiasts act on impulse and buy green coffee beans only to realize they don't know how to roast them. Below, FrontStreet Coffee shares their practical experience to introduce methods for roasting coffee beans at home.

Coffee Bean Roast Levels and Flavor Differences

When roasting at home, always start with low heat and gradually adjust later. Regardless of the tools used, you must constantly stir the coffee beans! At the same time, pay close attention to the color changes of the coffee beans! If the coffee beans change color rapidly but this change isn't uniform, it indicates the heat is too high or the stirring frequency is insufficient. If you feel the stirring is already optimal and cannot be improved, this confirms the heat is indeed too high! When this happens, immediately reduce the heat and remove the pot from the stove to quickly lower the temperature inside! After cooling, return it to the stove with adjusted heat to continue roasting.

If the coffee beans show no color change for a long time (3, 5, 10 minutes, or even longer), the heat is too low. In this case, you should appropriately increase the heat. When the coffee beans' color changes slowly and this change is uniform and consistent, it shows you've mastered the heat control perfectly! In this situation, while monitoring the coffee beans' color, you can also listen for the cracking sounds of the coffee beans.

As roasting continues, the beans gradually change from their initial light green color to yellow, then brown, then darker brown, and finally black. During this process, there is a first crack when the coffee beans change from yellow to brown, but this cracking process is very short and sometimes not obvious - sometimes ending after just 3-5 pops. This is the first crack.

There is a second crack during the transition from brown to darker brown. This second crack lasts 2-3 minutes or even longer, with very frequent popping sounds, like firecrackers crackling away! This is the second crack. The second crack is very noticeable. Generally, when the second crack just begins - when you hear about 10 pops - stopping the heat at this point yields medium-dark to full city roast beans.

Bean characteristics: dry surface, not yet oiled or slightly oiled, with small black spots on the brown beans! As the second crack popping continues, the roast level deepens. When the popping completely stops - meaning the second crack ends - the beans are basically completely black and severely carbonized.

Of course, this is also a roasting style, and many people enjoy this burnt flavor! Generally, beans from golden yellow to the later completely black state are all normal roasts, and you can stop the heat at any point in between. The resulting coffee will be drinkable! As for when to stop the heat, it depends on your personal preference!

Generally, the darker the coffee bean roast, the stronger the bitterness, while the coffee's flavor complexity and nutritional value also decrease. Fully carbonized beans do have a unique flavor, but they really don't have much nutritional value! Therefore, we don't recommend roasting to this level!!

What Tools to Use for Home Coffee Bean Roasting?

Recommended: Rotating Drum Specifically for Coffee Bean Roasting

The rotating drum is recommended because it's closer to the method used by professional coffee roasting machines. When using a roasting machine, coffee beans actually enter a rotating drum, and the machine maintains a constant speed of 60-65 revolutions per minute (adjustable based on different coffee beans and their conditions), allowing the coffee beans to heat more evenly inside the drum, ensuring the uniformity of the final product.

According to the personal experience of FrontStreet Coffee's baristas, when using a rotating drum to roast coffee beans, two points need attention: use low heat for roasting, otherwise the coffee beans can easily change color on the outside while remaining undercooked inside; after turning on and adjusting the heat, place the rotating drum and immediately start rotating at 60-65 revolutions per minute.

Using a rotating drum for roasting takes more than double the time compared to professional roasting machines. For example, FrontStreet Coffee uses a Yangjia 800N roasting machine to roast Brazilian Cerrado red bourbon coffee beans. The time from first crack to discharge is 3:30, achieving a medium-dark roast, with a total roasting time of 13 minutes.

This is Brazilian Cerrado coffee beans roasted by FrontStreet Coffee using professional equipment and sold commercially.

However, using a rotating drum to roast to a similar degree takes a total roasting time of 31 minutes. During this period, you need to constantly rotate the drum (60 revolutions per minute), and if you stop or slow down, the beans can easily burn... This can be said to be quite labor-intensive.

This is the same coffee beans roasted at home by FrontStreet Coffee's barista using a rotating drum.

Although roasting coffee beans at home is exhausting, it allows you to clearly and intuitively experience the coffee beans gradually changing from green raw beans to yellow, emitting sweet corn-like aromas, then slowly turning cinnamon-colored with caramel aromas, then gradually becoming chocolate-colored with roasted nut aromas.

2. The Simplest and Most Primitive Method - Pan Roasting

Every household has a cooking pan for daily cooking. In the long period before professional roasting machines existed, coffee was roasted using pans. Of course, pan-roasted coffee cannot compare to the output of professional coffee roasting machines.

The biggest reason is that during the stirring process, coffee beans cannot roll evenly in the pan, leading to uneven heating. But participation is what matters! During the roasting process, we can constantly watch the coffee beans change from green to chocolate color, and regardless of the final coffee flavor, it's a wonderful experience.

When pan-roasting coffee beans, first clean the pan thoroughly to remove grease from it. Home pans used for long-term cooking will certainly have residual grease. Therefore, be sure to clean thoroughly before roasting coffee! Generally, after washing the pan, heat it to dry the water, then add water to boil, pour out the water and heat again to dry! Repeat this process 1-2 times.

Heat until the pan surface is dry and no obvious grease is visible! When heating, once the pan surface is dry and free of moisture, add the green coffee beans! The amount shouldn't be too much - 100-200 grams is appropriate! Whether using electric, gas, or other heat sources doesn't matter much. The key is to control the heat properly! This can be compared to roasting other snacks or deep-frying food - the entire process requires moderate and stable heat.

3. Not Recommended, but Worth Trying - Electric Oven

Many people might choose an electric oven. Ovens generally cannot continuously stir the beans inside. If this is the case, it's recommended not to roast too many beans at once. Also, don't stack or pile the beans - spread them in a single layer on a tray. Then, based on color changes, periodically take them out to stir and ensure even heating of the coffee beans.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473