1. Fun with Coffee

I started roasting coffee in 2003. I was travelling the Big Island (Hawai'i) hopping around coffee farm shops to sample their coffee. I knew what kind of flavor I liked, but I could not meet coffee I really like there. I felt all the beans were roasted a bit darker than how I would like. At one shop, Country Samurai Coffee Company, the owner Walter Kunitake recommended to roast beans by myself. My first reaction was "Can I do that??", and he explained where to buy green beans a roaster. He told me even a hot air popcorn popper can roast coffee beans.

Update: On September 17, 2019, I was so thrilled to see Walter at his shop in Kona for the first time since 15 years ago!

So I bought some green beans from him, and did some roasting with a popcorn popper as soon as I went home. It was my first roasting experience and yes, it roasted green beans nicely to "coffee" beans! However, I quickly learned that the temperature of the popcorn popper gets too high too quickly and very difficult to control. After several roasting attempts, I decided to buy a real coffee bean roaster. The first roaster was Heartware iRoast, which was inexpensive (sold at about $150) and excellent home roaster. It used hot air just like popcorn popper. After 9 years, it stopped working. I was going to buy another iRoast, but by then, it was discontinued. (Maybe a dispute from Apple Computer...??) So, I got my current roaster Gene Cafe in 2012. It still roasts by hot air, but beans are in a rotating drum. It was more expensive (about $550), but I really like it. The only thing I don't like is it is a kind of hard to hear cracking sounds, which is very important when roasting coffee beans.

I buy green beans from Sweet Maria's, probably twice a year. I usually buy 2-pound bags of 5-6 different kinds. I like some and I don't like some, but that's part of fun. When I get really good ones, they are usually sold out by the time I realize they are very good. I guess people notice very quickly. But if they still have them, I re-order 5 more pound of them.

Measuring green beans. I roast about 150 grams at a time. This scale made by Hario is excellent.

This is my roaster. It takes about 12 minutes (plus ~10 min cooling time) to get nice light roasted coffee I enjoy. I set the highest roasting temperature to 473 F (245 C), while the roaster can go up to 485 F (252 C). To decide when to stop roasting, we use a combination of hearing cracking noise + seeing the color of beans. Once stable roasting time is found for desirable roast, we can roast by time, but the room temperature should be consistent, because the room temperature affects roasting time.

There are two cracking phases while coffee beans are roasted. Cracking happens because of expansion of beans, just like popcorn. Roasting should be stopped not too long after first cracks finish for medium roast beans, while we need to get into second cracks for dark roast beans. My preference is to stop roasting right in the middle of first cracks, which produce nice light roasted beans.

Contrary to what we think, "freshly roasted coffee beans" (I mean immediately after beans are roasted) don't taste good. It takes at least half day after roasting to gain good flavor. From my experience, a prime of flavor is reached 3-4 days after roasting, which I believe depends on how you roast beans + kinds of beans.

Measuring roasted beans for brewing. My measure is 24 grams for 380 grams of water to pour over (drips about 12 oz).

This is my grinder made by Kitchen Aid. I've been using this since 2004.

This is my back up manual grinder made by Hario.

This is my dripper made by Hario. Very nice.