January 18, 2014

Direct-Flame Coffee Roasting with a "Perforated" Pot/穴の開いた鍋による直火コーヒー焙煎

Note: The following description applies to direct-flame not hot air coffee roasting.
注:下記の記述は直火(熱風ではなく)コーヒー焙煎に当てはまることです。
 
First of all, let me show you my ideal coffee roaster No. 1.
まずは、私が理想とするコーヒー焙煎機一号機を見て下さい。
I have attached a piece of bamboo as a handle to facilitate shaking.
簡単に振れるよう、柄として竹を付けました。

This time, I decided to test whether it could roast 400 g of coffee beans evenly.
今回は、コーヒー豆400 gをムラなく焙煎できるか試すことにしました。 
You have to place a lid or something similar on the top for the first 10 minutes of roasting to keep the moisture inside the pot high.
This time, I decided to cover about 3/4 of the top.
焙煎の最初の10分間は、上部に蓋などをして、鍋の内部の湿度を高く保つ必要があります。
今回は、上部の約3/4を覆うことにしました。 
Note: As for the milk can roaster, you need not cover the top, because of its great height. A great feature of the milk can roaster is that you don't have to worry about exhaust air control.
注: ミルク缶焙煎機の場合は、高さがあるので、上部を覆う必要はありません。ミルク缶焙煎機の偉大な特徴の一つは、排気のコントロールを心配する必要がないことです。

Start roasting with the heat set to medium or high, depending on the heating power of the burner. If your burner has a heating power of 2,600 kcal/h or greater, you may want to start with medium. I started with the heat set to high because of the large amount of coffee beans.
Make sure that chaff starts to come off in about 3-4 minutes. If earlier, you need to lower the heat.
It is very important to keep in mind that coffee roasting is a two-phase process, drying phase and chemical reaction phase.
I first thought that I'd dry the beans for 12 minutes, but first crack occurred at around 11:45, so I changed my mind and removed the lid. Then, I took this photo and replaced the gas cylinder with a new one.
コンロの火力によりますが、火を中か強にして焙煎を始めます。火力が2,600 kcal/h以上のコンロであれば、中火で始めたほうがいいと思います。私は、コーヒー豆の量が多いので、火を強にして始めました。
極めて重要な留意点は、コーヒーの焙煎は2段階の工程であることです。乾燥段階と化学反応段階です。
最初は12分間、豆を乾燥させようと思っていたのですが、1ハゼが11:45に起きたので、考えを変え、蓋を取りました。この写真を撮って、ガスボンベを新しいのに交換しました。
Also, keep in mind that first crack should occur at 12-14 minutes after the start of roasting.
また、1ハゼは焙煎開始後12~14分後にすべきだということにも留意して下さい。

First crack continues for about 1-2 minutes. At this point, the beans lose weight by about 15%. When you bring them to second crack, they will lose weight by up to 20%.
1ハゼは1~2分続きます。この時点で、豆は15%程度重さが減ります。2ハゼまで持っていくと、20%まで重さが減ります。

When you have roasted your beans to the desired level, cool them immediately. I have an electric fan (not shown).
豆を好みのレベルまで焙煎したら、すぐに冷やして下さい。私は電気扇風機(写真には写ってません)を持っています。

I roasted my beans for a total of about 16 minutes.
I got 325 g of roasted beans.
合わせて16分程度焙煎しました。
焙煎した豆が325 gできました。
18.8% weight reduction.
重さの減った割合は18.8%。

Look at all the chaff generated during roasting:
焙煎中に出たチャフを見て下さい: 
I'm really glad that my pot roaster can roast 400 g of coffee beans properly.
私の鍋焙煎機はコーヒー豆400 gをちゃんと焙煎できて、うれしいです。

But, I have a new mission!
Yesterday, I found this great toaster oven sold for 500 yen at the second-hand store. Of course, I grabbed it!
しかし、私には新たなミッションが!
昨日、リサイクルショップでこのすごいオーブントースターが500円で売っていました。もちろん、すぐ買いました!
Two heating elements at the top and one at the bottom.
ヒータは上に2つ、下に1つ。 
It has a temperature control!
温度調節もあります! 
I think I'll convert this toaster oven into a coffee roaster.
このオーブントースターをコーヒー焙煎機にしようと思います。 

To be continuted. I haven't yet talked about the features of my three roasters (milk can, kettle, and alumite pot roasters).
続く。私の3種類の焙煎機(ミルク缶焙煎機、やかん焙煎機、アルマイト焙煎機)の特徴について、まだ話してません。

4 comments:

Fräulein Trude said...

Wow, I did not find the sieve but I will try to build my own roasting pot. Maybe I am going to use a tin cookie can - guess I will drill in some holes with an electronic driller (whenever there is time...)

Hiroyuki said...

Kiki: In that case, burn off the coating inside the can before use.

Electric drill? Why not simply ask your husband to do the job and the roasting, too?

Hiroyuki said...

Kiki: Actually, drilling holes with nails is better, because then the burr around each hole will cause the beans to turn upside down while you are shaking the pot.
I would suggest selecting an aluminum or alumite pot rather than an iron one. Like I said before, I had some difficulty making holes on the bottom of my iron kettle with a screw.

Fräulein Trude said...

My husband is not interested in roasting coffee or any kind of craftmanship including to drill holes in walls, wood work and such. As long as it is not car related it is always up to me but I am used to it, no problem at all.