Enhancing tea by roasting - Why do we roast tea?
Our family does all our own roasting. We do both charcoal roasting, and electric roasting. While our preference is for the traditional art of charcoal roasting, there is no doubt that the art of electric roasting has its place too. For this reason, we wanted to write some information on the history, and benefits (and negatives) of electric roasting.
Roasting is the last step in the process to make oolong tea; even unroasted oolong will usually go through a very quick roasting cycle to make sure the tea is thoroughly dried. Without roasting or thorough drying, the flavor of oolong will change rapidly once exposed to oxygen or moisture. This is also why we vacuum seal all our tea. By roasting and vacuum packing our tea, we ensure the flavor and quality of the tea will remain stable and ready for you to drink.
There are two broad roasting styles; charcoal roasting (Tan Bei / 炭焙), or electric roasting (Dian Bei / 電焙).
In the 1970s, the first widely adopted electric roasting machines were developed. At this time, they came in two styles, the electric coil type - basically a metal plate that contains electric coil heating elements with bamboo roasting baskets placed on top - and the forced air type - which somewhat resembles an electric kiln or industrial refrigerator. The electric coil roasting machines can be seen as a middle step between charcoal roasting, and the more modern forced air roasting machines. These days, most people prefer to use the forced air type. This style of roasting machine allows for a larger amount of control over the roasting process, a more precise level of roast, is more convenient, and you can roast more tea at one time.
While electric roasting machines are certainly more convenient than charcoal roasting, they still require knowledge, attentiveness, and passion to operate well. Without these traits, it is easy to over roast your tea, or even burn it into an unusable state.
Photo below from left to right: Traditional charcoal roasting
Electric coil type roasting machine
Forced air type electric roasting machine
Here are some of the pros and cons of using electric roasting machines:
1. It’s much easier to control the Time and Temperature. Because time and temperature are the key points for roasting, being able to easily adjust roasting parameters will greatly increase your chances of a successful roasting process.
2. Electric roasting machines produce a more even roast. This allows all of the tea being roasted to reach the same level of dryness at the same time, which can result in a better taste than charcoal roasting.
1. It’s hard for electric roasting to fully penetrate the cores of the tightest rolled oolongs. Inexperienced roasters cannot control this process very well, and you end up with rolled oolongs that are very dry on the outside, but still slightly damp on the inside. Over time, this residual moisture will be released into the “finished" tea and cause the tea to taste sour, or in some cases, grow mold.
2.Electric baking lacks the unique aroma and taste of charcoal roasted tea.
These photos were taken during our last electric roasting cycle. In these photos, you can see the basic steps used when roasting with a forced air roasting machine. To get the desired roast we wanted out of this tea, I performed three roasts on it over the course of three weeks.
In our next blog, we will introduce the charcoal roasting process!