September 23, 2013

Milk Can Coffee Roasting/ミルク缶コーヒー焙煎

In Japan, today is the last day of three consecutive national holidays, and I finally got around to trying to roast some coffee beans with my milk can roaster.
日本では、今日が三連休の最終日です。やっとミルク缶焙煎機でコーヒー豆を煎る暇ができました。
 
A milk can roaster is no joke. Nakagawa-san of Flavor Coffee sells it for 5,000 yen (including 1-kg green beans). He claims that it can roast coffee beans just like a commercial roaster.
ミルク缶焙煎機は冗談なんかではありません。フレーバーコーヒーの中川さんは5,000円で売っています(生豆(きまめ)1キロ付き)。業務用の焙煎機と同じようにコーヒー豆を煎ることができると言っています。
 
If you ever decide to make one by yourself, refer to the thread that I started on eGullet a long time ago.
自作する場合は、昔私がeGulletで始めたスレを参照してください。
 
Note that the milk can is 13 cm in diameter and 18 cm in height. The roaster is designed so that first crack occurs in 12-14 minutes when used with a 2,500 kcal portable gas stove. The size and the number of the holes at the bottom determine the roasting time. The height of the can is also important.
ミルク缶は直径13 cmで、高さ18 cmです。この焙煎機は2,500 kcalの携帯用ガスコンロで12~14分で1はぜが起きるように設計されています。底部の穴の大きさと数が焙煎時間を決めます。缶の高さも重要です。 
  
 
 
I decided to do the roasting in the garage.
ガレージで焙煎することにしました。 
The roaster is capable of roasting up to 200 g of green beans at a time, but Nakagawa-san recommends roasting 150 g so you won't get tired from shaking the roaster. You need to shake the roaster constantly once per second for 14-16 minutes.
この焙煎機は生豆を一度に200 gまで焙煎できますが、中川さんは焙煎機を振り続けて疲れないよう、150 g焙煎することを薦めています。1秒に一回コンスタントに14~16分も振り続ける必要があります。
 
165 g of green beans:
生豆165 g: 
The gas stove has 2,600 kcal/h. I started with the heat set to high. The chaff started to come off 2 minutes later. Bad sign! It should start to come off in 3 minutes. I lowered the heat to medium. You have to reduce the moisture inside the beans for the initial ten minutes.
Ten minutes later, I turned the heat to high, and the beans started to crack immediately. I reduced the heat to medium again. Twelve minutes later, I turned the heat to high again. Fifteen minutes later, I stopped roasting, before second crack.  
ガスコンロは2,600 kcal/hです。火力は高にして始めました。チャフが2分後に飛び始めました。悪いサインです!チャフは3分後に飛び始めるようにしないといけません。火力を中に下げました。最初の10分間で豆の中の水分を抜く必要があります。
10分後、火力を高にすると、豆がすぐにはぜ始めました。火力をまた中に下げました。12分後、また高にし、15分後、2はぜの前に焙煎を止めました。
 
Chaff:
チャフ:
I immediately cooled the beans. I have a cooler, given to me by Nakagawa-san.
豆をすぐに冷やしました。私は中川さんからもらった冷却器を持ってます。     
Coffee beans, roasted for 15 minutes:
15分焙煎したコーヒー豆:  
I then transferred to a metal sieve.
Weight: 145 g
金属製のざるに移しました。
重さ:145 g 
Compare the beans (right) with the Mocha beans bought from Flavor Coffee:
豆をフレーバーコーヒーから買ったモカと比べてください: 
I ground some of the just roasted coffee beans.
煎りたてのコーヒー豆を少し挽きました。  
Naturally, the coffee grounds bloomed remarkably.
当然、コーヒーの粉はすごく膨れました。 
More gas coming out as I poured water.
お湯を注ぐとガスがもっと出てきました。 
End of brewing.
抽出終了: 
I used a Matsuya wire-frame dripper, but brewed coffee like the Melitta/Kalita way.
松屋の金枠ドリッパーを使いましたが、メリタ・カリタ風にコーヒーを淹れました。 
Resultant coffee:
できたコーヒー: 
I drank a cup,
一杯飲みました。 
and found it was good although a little bitter.
ちょっと苦いですが、美味しかったです。
 

5 comments:

Dan said...

Looks good hiroyuki ...Your final product has a nice mat finish ...I really like the way you tune your heat like a pro to reach thermal stability ..Maybe hooking up a thermometer to monitor the inside temparature might be a good idea to replicate future roast profiles and if you can just roast by sound and smell, closing the mouth of the milk can can increase roasting speed ..But your product looks like the store bought coffee bean ...Very nice !

Hiroyuki said...

Dan: Thanks for the suggestion. Nakagawa-san once attached a thermometer to a milk can roaster.
http://www.flavorcoffee.co.jp/flavor3.html
See the last photo, but he writes:
The effect of the thermometer is unknown because I have never actually used it.

Closing the upper open end of the can is a bad idea, however. In the Shukan Flavor video, he explains how the milk can roaster can "automatically" control the exhaust, starting at around 19:00.

I was wrong when I said that he doesn't explain the two styles of shaking the roaster. He does explain them, starting at around 44:00, but in a different way. He says, "With the "chahan (fried rice)" style of shaking, you can turn all the beans upside down at once."

Dan said...

Hiroyuki,

you are correct ...now that I think about it, closing the mouth of the milk can will be a bad idea due to the smoke and might even cause the beans to have a smoky flavour ...not sure though ...Anyways as I dont have a gas grill and as all I have is a electric coil ...I am using "whirly pop" ...America's famous stove top popcorn maker ...I made a batch of ethiopian and it was not bad ...Its almost similar to milk can ...but instead of vertical motion of the beans in a milk can ...here the beans move in a horizontal direction and uses the phenomenon of heat conduction and the only catch is if the beans dont move it can get burnt .....It can be automated also as shown in the below 2 videos ....


Manual :

http://www.youtube.com/watch?v=qR4rfcE7KdU

Automatic

http://www.youtube.com/watch?v=wFUATqkC5fo

I tried the air pop method ...electric popcorn maker and coffeee tasted flat and was flavourless ...but the direct heat is surely rewarding ...What do you think about this Stovetop method ...Do you think that this may be a better alternative for folks who dont have a gas range and can be automized too ?
By the way the greatest news with this is besides being able to control heat and lot of other factors ...guess what u can make as much as 1 pound of bean ( 453 grams ) ...Cool huh ?

Hiroyuki said...

Dan: Nakagawa-san says that once air leaves the upper open end of the can, it will never come in contact with the coffee beans again. He also says that you make the flavor of coffee with exhaust (i.e., by controlling the exhaust).

(I'm a novice when it comes to coffee roasting, and I don't understand everything Nakagawa-san says.)

The stovetop method sounds good, of course, but as I said previously, isn't 6-7 minute roating too short? I wonder if you can develop the flavor of coffee in such a short time.

Being able to roast one pound of coffee beans in a single batch sounds really cool, provided that you can roast all beans evenly.

Dan said...

Hiroyuki:

6-7 minutes was only for the hot air ( electric) pop corn popper which is very short for coffee roasting and I saw coffee beans being chipped ....like "coffee shrapnel" ..this was due to excessive heat ( which I was not able to control in electric ) and intense production of co2 which causes the bean to literally shatter and explode...and coffee flavour was flat ...But whirley pop is a manual stovetop ...where you can control heat ...and still use it for roasting 1/2 - 1 pound of beans ....I am impressed with my 1st try and you can take to roast beyond 10 minutes - 15 minutes if you use less heat ...and above all it makes the best popcorn ...From the manufacturer's site I was able to conclude that the patented stir design helps in even roasting and helps maintain cabin temparature over 450F , which is rather conducive for coffee roasting .. ..and guess what this little guy can be automised and I like the taste of coffee which matters most ...So I am going to experiment with diff amounts of beans and diff levels of heat ...I heard somewhere that in coffee roasting 2 elements are of paramount importance ...heat and time ...so real technique is using the least amount of heat and least amount of time to get your best batch ... so I guess I need to find out where my least heat and lowest time merge point .....to compute my best roast ...