June 29, 2014

Coffee Roasting with My Perforated Shallow Pot/穴あきの浅鍋によるコーヒー焙煎

Here is a summary of what I have written about coffee roasting with my perforated shallow pot, plus some additional information.

For information about this and other roasters, check out this post.

Coffee roasting is a two-phase process:
1. Drying phase, where you must dry the coffee beans sufficiently.
The drying phase should at least be 9 minutes long. It's usually 10-12 minutes long.
The weight loss is about 7% at the end of the drying phase.
2. Chemical reaction phase, where you must cause a large number of chemical reactions by increasing the amount of heat applied to the coffee beans.

My shallow pot roaster is very light, 325 g, which is an important feature because you have to keep shaking it for up to 16 minutes.
私の浅鍋焙煎機はとても軽く、325 gです。16分程度まで振り続ける必要があるので、とても重要な特徴です。
Because it's light, it has a low heat capacity, so it does not require pre-heating and and is useful in preventing coffee beans from being over-roasted. If you suspect your coffee beans are over-roasted, simply remove the pot from the stove, turn down the heat, and start roasting again.

You will need:
1 or 2 metal sieves, a cooling device (or just a fan), leather gloves, a timer, a vacuum cleaner (option).

You will also need a portable gas stove, a gas cartridge, a spare cartridge.
A spare cartridge is required, not optional.

Currently, I make it a point to roast 360 g of green coffee beans at a time.
現在、私は生豆(きまめ、なままめ)を一度に360 g焙煎することにしています。
Cover the pot almost entirely with some aluminum foil.
Start with medium heat, provided that your stove has a heating power of about 2,600 kW/h.
CORRECTION: 3.0 kW (2,600 kcal/h)
コンロの火力が2,600 kW/h程度とすると、中火で始めます。
訂正: 3.0 kW (2,600 kcal/h)
Start roasting. Press the start button of the timer. Start shaking the pot.
(I forgot to press the start bottom, and pressed it 8 seconds after I turned on the gas.)

Two minutes passed. At this point, no chaff should come off the beans. If it does, remove the pot from the stove immediately, turn down the heat, and start roasting again.

3 minutes passed. It's hard to see from the video, but chaff started to come off the beans and fall down on the stove.
9 minutes passed. If first crack occurs at this point, remove the pot from the pot immediately, turn down the heat, and start roasting again.

In this particular case, first crack started at around 10:30. Still too early, but I continued to roast without turning down the heat.

11 minutes passed.
Keep roasting while listening to the sound carefully.
I forgot when I turned up the heat to high... Probably 12 minutes after the start of roasting.

To be continued.

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