How long does it take for green coffee beans to roast? How to roast coffee at home without a bean roasting machine?

Not long ago, Qian Jie was reading a book about coffee roasting and noticed this sentence: "Roasting coffee can sometimes be a bit monotonous and boring, but the appearance of a burst is always exciting."

Perhaps to many people, the term "burst" may seem familiar but it is unfamiliar. As a signal that coffee beans are beginning to "ripen", it often appears in daily articles on the front street, allowing us to better understand coffee. The status of different roasting stages, as well as the origin and formation of various flavors. Then the question arises, what kind of sound does "explosion" sound like?

In order to personally experience the sound of a "burst", Qianjie specially prepared enough raw coffee beans. After returning home, he found a pan, and then used the open fire on the stove to "bake" it by frying. By the way, I can also make a "How to brew coffee at home without a bean roasting machine?" The experiment is really killing two birds with one stone!!

(Warm reminder: Because it is a simple and crude family model, there is not much rigorous data here, let alone professional measuring equipment. The whole process will be based on actual conditions to judge how to adjust the firepower and when it will end. Therefore, the coffee beans that come out may be stale, they may become mushy, or they may be half-cooked. Let's wait and see.)

For the first pot of coffee, Qianjie chose a sun-cured bean, Ethiopia's Santa Vini. As a first attempt, for safety reasons, Qianjie turned on the smallest light fire, immediately poured in half a bowl of raw beans and heated it, and started counting. While observing the color changes of the beans, keep the pan turning throughout the process, trying to heat each particle evenly.

About 5 to 6 minutes, some raw beans began to turn slightly yellow; about 7 minutes later, more than half of the raw beans showed obvious color change, and the silver skin gradually fell off. After blowing away the silver skin, they continued to turn.

However, because the firepower was too small and the coffee beans absorbed heat too slowly, the front street did not receive the sound of a "explosion", so they had to temporarily adjust the firepower to a low level and then continue to stir fry. It took about 20 minutes for some raw beans to turn brown. It was not until 22 minutes that the first coffee bean made a popping sound, and then smoke began to come out of the pan, and there were constant "Pa, Pa, Pa" sounds.

Since beans are native to Ethiopia, the grains are large and small. Once they are not turned in time, they are easily heated unevenly. At 24:00, Front Street observed that half of the coffee beans had passed a burst and continued to turn from brown to dark, while the other half was still in brown and had not yet entered the burst stage. In order to prevent zooming, the final time was 26:00. Bake out at time. After turning off the heat, find a stainless steel container and quickly pour the coffee beans into cool to prevent them from heating up.

For the second pot of coffee, Front Street was replaced with water-washed Kafa Forest. The goal was moderate roasting. The grains of this bean were relatively uniform and easier to control the heat.

After learning the lesson from the first time, when adjusting the fire power, first turn on medium heat to heat the pan. Put your hand on the top of the pan. When you can feel a burst of heat, you can immediately pour in the raw beans, and then adjust the fire power to low heat. (You can also drop a small drop of water into it. If it boils and evaporates quickly, it means that the pot has reached the target temperature)

Keep the heat low and continue to stir. In about 4 to 5 minutes, the raw beans begin to turn yellow. In 10 minutes, individual grains turn light brown and exude the aroma of popcorn. At 12 minutes, the raw beans begin to pop, and the front street immediately changes the stove to light fire. As the crackling sound became concentrated, the smoke gradually increased. Between about 14 and 15 minutes, the coffee beans in the pot stopped making sound and completely turned dark brown. At 16 minutes, the roasting ended.

As the saying goes, since everyone is here, after listening to the "first explosion", it is natural to listen to the "second explosion". Therefore, when Qianjie stir-fried the third pot of coffee beans, the goal was to roast the coffee beans in mid-to-deep, and the coffee beans were still sun-exposed to Santa Vini.

Because of the experience of the second pot of coffee, Qianjie still used medium heat when adjusting the heat this time. After pouring in the raw beans, they were then stir-fried steadily over low heat. They began to turn yellow in about 4 to 5 minutes, and about 8 minutes. As the raw beans turned brown, a large amount of silver skin fell off, and a faint nutty aroma also floated out of the pot. At the ninth minute, the smaller raw beans began to burst into a burst and produced smoke.

The firepower was once again changed to light fire and continued to stir. When the time comes around 13 - 14 minutes, most of the particles have stopped exploding. After 1 - 2 minutes of silence, a small popping sound can be heard, indicating that the coffee beans have begun to enter the medium and deep roasting stage. Stir fry for about 10 seconds, take out of the pan to cool.

Through comparison, it can be found that the first pot of coffee beans are in a half-cooked state, and many particles are still yellow, obviously half-cooked; the color value of the second pot is relatively uniform and tends to be moderately roasted; the overall coffee in the third pot is moderately deep, and some particles show signs of local burns and discoloration, which need to be removed manually.

(Strains and scalds/turning into bruises)

After a few days of bean-growing period, Qianjie picked out obviously raw and burnt coffee and brewed each pot of samples to try.

The first pot is half-cooked Santa Vinny: the ground coffee powder has the aroma of popcorn and fried peanuts. The color of the coffee liquor is light, and only a little berry acid and black tea feel can be drunk in the mouth. There is almost no "coffee flavor", obviously because too many beans are undercooked, resulting in insufficient coffee extraction.

The second pot is the "moderately baked" Kafa Forest: after grinding, it smells sweet aroma of toast and fried nuts. The first taste of the coffee liquid is the sweet aroma of chocolate, sugar, and hazelnut, with a slight tipsy flavor. As the temperature drops slightly, you can feel the acidity of citrus fruits. The overall softness is relatively weak and the flavor intensity is weak.

The third pot is a "medium and deep baked" Santa Vinny: after grinding, you can smell the aroma of lemon and cream cookies. The coffee liquor has the deepest color and tastes candied fruit, roasted hazelnut, caramel and other flavors. The aroma is sweet and sweet. Not bitter, the sour taste is not obvious, but the mellow degree is low and there is not much ending rhyme.

Good news: The pan can "roast" coffee beans!!

Bad news: The ground is covered with silver skin, and we're going to sweep the floor again...

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