How to Roast Coffee Beans at Home: Illustrated Methods & Flavor Differences by Roast Level

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

However, many people act on impulse, buying green coffee beans without knowing how to roast them. Below, based on FrontStreet Coffee's actual experience, we'll introduce methods for roasting coffee beans at home.

Roast Level Flavor Differences

When roasting at home, always start with low heat and gradually adjust. Whatever tool you use, you must constantly stir the coffee beans! Meanwhile, pay close attention to the color changes of the coffee beans! If the coffee beans change color quickly 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 means 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, place it back on the stove with the adjusted heat to continue roasting.

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

As roasting continues, the beans gradually change from their initial light green to yellow, then to brown, dark brown, and finally black. During this process, there's a first crack as the beans change from yellow to brown, but this cracking process is very short—sometimes barely noticeable, ending after just 3-5 sounds. This is the first crack.

During the transition from brown to dark brown, there's a second crack. This cracking process lasts 2-3 minutes or even longer, with very frequent sound patterns, crackling like firecrackers! This is the second crack. The second crack is very easy to notice. Generally, when the second crack just begins—that is, when you hear about 10 sounds—stopping the heat at this point yields medium-dark to full city roast beans.

Bean characteristics: dry bean surface, not yet oily or slightly oily, with small black spots on the brown bean body! As the second crack sounds continue, the roasting deepens. When there are no more sounds—that is, when the second crack ends—the beans are basically black and severely carbonized.

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

Generally, the deeper the coffee bean roast level, the heavier the bitterness, while the coffee's flavor complexity and nutritional value decrease. Fully carbonized beans indeed have a unique flavor, but they have very little nutritional value! Therefore, we don't recommend roasting to this level!

What Tools to Use for Home Coffee Bean Roasting?

1. Recommended - Dedicated Coffee Bean Roasting Drum

Using a drum is recommended because it more closely mimics 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 rotations per minute (adjustable according to different coffee bean conditions), allowing the coffee beans to heat more evenly within the drum, ensuring uniformity of the final product.

According to the personal experience of FrontStreet Coffee's baristas, when using a 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 uncooked inside; after turning on and adjusting the heat, place the drum and immediately start rotating at 60-65 rotations per minute.

The time required for drum roasting is more than double that of professional roasting machines. For example, FrontStreet Coffee uses a Yangjia 800n roasting machine to roast Brazilian Cerrado Red Bourbon beans, with a time of 3:30 from first crack to discharge, achieving a medium-dark roast level, with a total roasting time of 13 minutes.

This is Brazilian Cerrado coffee bean roasted by FrontStreet Coffee using professional machines and sold commercially.

When using a drum to roast to a similar level, the total roasting time is 31 minutes. During this period, you must constantly rotate the drum (60 rotations per minute), and if you stop or slow down, the beans will easily burn... It can be said to be quite labor-intensive.

This is the same type of coffee bean roasted at home by FrontStreet Coffee's barista using a drum.

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

2. The Simplest and Most Primitive Method - Pan Roasting

Every household has cooking pans 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 main reason is that during the stirring process, coffee beans cannot roll evenly in the pan, leading to uneven heating. However, participation is what matters! During the roasting process, we can constantly witness the coffee beans changing from green to chocolate color. Regardless of how the final coffee tastes, it's a wonderful experience.

When pan-roasting coffee beans, first clean the pan thoroughly to remove grease. Household pans used for long-term cooking will definitely have residual grease. Therefore, you must clean them thoroughly before roasting coffee! Generally, after washing the pan, heat it to evaporate 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 and the pan surface is dry without moisture, add the green coffee beans! The amount shouldn't be too much—100-200 grams is suitable! Whether you use electricity, gas, or other heat sources doesn't matter much. The key is to control the heat well! This can be compared to roasting other nuts or fried foods—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 layer the beans—meaning spread them in a single layer on the pan. Then, based on color changes, periodically take them out to stir and ensure even heating of the coffee beans.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473