July 10, 2018

Hybrid Roasting/ハイブリッド焙煎

Ingredient: Green coffee beans
For example, 235 g of green beans if you want 200 g of medium roasted coffee (weight reduction of 15%)
You will need: Some kind of roaster. Shown below is a gingko nut roaster.
材料: コーヒー生豆(なままめ、きまめ)
例えば、中煎りのコーヒー(重量減15%)が200 g欲しければ、生豆は235 g。
必要な器具: 何らかの焙煎器。ここでは、銀杏煎り器。
Kitchen scale
Microwavable container in which to put green coffee beans
Plastic wrap
2 bamboo sieves
1. Put green beans in the container, wrap with plastic wrap, set the timer to 9 minutes and start it, and microwave at a low wattage (200 W, for example) for 9 minutes.
1. 容器に生豆を入れ、ラップをして、タイマーを9分に設定して、スタートさせ、電子レンジで、低いワット数(例えば200W)で9分、加熱する。
You may want to check the beans and shake the container occasionally but this is not essential. What counts most in this step is to make sure that first crack does not occur. If first crack does occur, take the necessary measures such as lowering the wattage and turning off the microwave for some time.
2. Transfer the beans to the roaster. Start the timer from 0. Roast the beans over the gas stove while constantly shaking the roaster until the desired roast level is reached. First crack (popping sound) should occur 1-2 minutes after the starts of roasting.
2. 豆を煎り器に移し、タイマーを0からスタートさせ、豆をガスコンロの上で、常に煎り器を振りながら、希望する焙煎度まで焙煎します。1ハゼ(ポン、ポンという音)は、焙煎開始から1~2分で始まるはずです。   
First crack should end in 2-3 minutes. You may want to stop the roasting for a medium roast. The weight reduction should be around 15-16%. For a dark roast, continue to roast, and second crack (crackling sound) will occur. Stop the roasting when the desired roast level is reached. The weight reduction should be around 18-20%.
3. Transfer the beans to one of the sieves. Transfer them to the other sieve. By repeating this step, cool down the beans and remove the chaff. You may want to do this step outdoors.
3. 豆を一方のザルに移します。それを他方のザルに移します。これを繰り返し、豆を冷まし、チャフを除きます。この作業は外でやったほうがいいです。
Note 1: Chaff will scatter around the gas stove while you are roasting.
Note 2: Your gas stove may have a feature that automatically turns down the heat if nothing is placed on it. You will then need to press the buttons as many times as necessary.
Caution: Smoke will be generated during roasting. Make sure that the smoke detector, if installed, is not activated due to the smoke.
4. Measure the weight of the roasted beans.
You may want to keep a record of the details of your roasting session, initial weight, when first crack occurred, when it ended, the total roasting time, and the final weight.
4. 焙煎した豆の重さを測ります。
5. Let the beans sit overnight. Enjoy the "san tate" (lit. three just's, that is, just roasted, just ground, and just brewed) coffee the next day.
5. 豆は一晩寝かせます。翌日には、「三たて」(煎りたて、挽きたて、淹れたて)のコーヒーを楽しめます。  
(I simply use a tea strainer and a paper towel for brewing.)

For roasting with a milk can or a 26-cm diameter shallow pot, you need to shake the can or pot continuously for 12-16 minutes. With this hybrid roasting method, you only need to shake the roaster for 2-6 minutes.
ミルク缶や直径26 cmの浅鍋での焙煎では、缶や鍋を12~16分もずっと振り続ける必要がありますが、このハイブリッド焙煎方法では、2~6分程度、煎り器を振るだけです。
This time, I went for a dark roast of a 18% weight reduction. Thus, to obtain 200 g of roasted coffee, I needed
200/(1 - 0.18) = 200/0.82 = 244 g green beans.
I started microwaving the beans at 500 W. First crack occurred at 5:00. I turned off the microwave, reduced the wattage to 200 W and restarted the microwaving.
200/(1 - 0.18) = 200/0.82 = 244 gの生豆が必要。
豆を500 Wの電子レンジで加熱し始めました。1ハゼが5:00に起きました。電子レンジを止め、ワット数を200 Wに落とし、加熱を再開しました。
1st crack occurred 2:00 after the start of roasting. I stopped roasting soon after 2nd crack started. The total roasting time was 6:00.
I though I made it, but I later learned that the weight reduction was only 16%.
Anyway, I prefer coffee at this roast level. Ideal for iced coffee and coffee jelly!


Anonymous said...

looks like the result is less uniform than your usual roasting method, isn't it?

Hiroyuki said...

Anonymous: Maybe so, but at a negligible level, I think. At one time, I wanted to create a mechanism whereby the beans could be stirred while being microwaved, but I gave up partly because I thought that wouldn't be worth it.