On another shelf in the same shop stand oolong and black tea. Pick up a packet and fire turns up in the wording here too: roasted, baked, hongbei. The leaf is a brown much like hojicha's. A few steps along, and the same words are attached to tea from another country.
What follows looks in turn at where the fire falls, what it is for, how long it takes, and where the aroma ends up.
A second fire, after drying
Pinch the brown leaf and it is light and dry, much like hojicha. Oolong and roasted black tea both meet fire again after they have dried.
Set the processes side by side and both give dried leaf a second fire. Compare the times, though, and the charcoal roasting of rock tea runs orders of magnitude longer than hojicha's. The sources agree on where the fire falls, and not much more. First, the making of oolong from across the sea.
Drying, and drying again
Read a process chart from the top and the word drying keeps coming back. In oolong, the fire returns after the leaf has dried.
The oolong described by a tea research body across the sea is withered, fixed by heat, dried and rolled into balls. Last comes drying and roasting, the same shape as Japanese hiire.
Nor is there only one purpose. The same body lists making the tea keep longer, correcting green or unwanted notes, and giving the tea its own aroma. The sources set out the aims and leave it there. After purpose comes time over the fire.
Fires counted in seconds, fires counted in hours
Descriptions of charcoal-roasted rock tea give the time in hours. Against hojicha, the difference is one of orders of magnitude.
A shop selling the tea says that a single charcoal roast of rock tea takes close to half a day. Repeat it, and the total grows longer still. Hojicha roasting, in laboratory trials, lives in seconds and minutes.
The sources let a shop's account and a trial's figures sit side by side, and no more. After time, the black tea shelf.
Figure 5-3-1Where the fire after drying comes, and how long it takes
| Tea and process | Order of the process | Time taken | Source |
|---|---|---|---|
| Hojicha roasting | sencha or bancha, already fired, is roasted | 40–420 seconds (10 minutes or more in an industry body's account) | Sasaki et al. 2020 / GJTA (an industry body) |
| Japanese sencha hiire | aracha → sorting → hiire → blending | 20 minutes to 5 hours (three types of hiire machine) | Yamaguchi 2006 (process) / Shiono 1974 (time) |
| Taiwanese Dong Ding oolong | sun withering, indoor withering → heat fixation → initial drying → ball rolling → drying and roasting (hongbei) | not stated | Tea and Beverage Research Station, Ministry of Agriculture (Taiwan) |
| Black tea (roasted black tea) | withering → rolling → oxidation → drying → (roasted black tea only) roasting | not stated | Chanomi Tsuruen (process) / Senrei, Makinohara Yamamotoen (product descriptions) |
| Charcoal roasting of Wuyi rock tea (Fujian, China) | not stated | 8–12 hours per roast, up to 36 hours in total over several roasts | Path of Cha (a tea retailer) |
Roasted black tea and the scent of fruit
The black tea shelf has its own packets marked roasted. A scorched smell is not the only place roasting can lead.
Roasted black tea is finished black tea given one more fire. Black tea is already dried with hot air in the making, so this roast is not its first fire. One tea farm roasts summer-picked black tea and speaks of a rich sweetness and a roasted aroma. Another roasts hard and says the result carries a sweet scent like peach and grape.
The reactions belong to the same family as those that make hojicha's aroma. A report on roasting rock tea says the roasted aroma moves towards a floral one while the tea is stored. The cultivars and processes differ, though, so the figures cannot simply be carried across.
What the word roasting means from one shop to the next is taken up in the following chapter. The figures and where they come from are gathered at the end.
The numbers in detail
- Taiwanese oolong
- Dong Ding oolong, as described by Taiwan's Tea and Beverage Research Station, Ministry of Agriculture. Withering, heat fixation, initial drying and ball rolling end in drying and roasting (hongbei).
- Process table
- Where the post-drying fire falls for each tea is set out in Figure 5-3-1.
- Aims of hongbei
- From the same station's account of specialty teas: extending storage life, correcting green and unwanted notes left in the initially processed tea, and giving the tea its own aroma.
- Rock tea times
- The charcoal roasting of Wuyi rock tea (Fujian, China) comes from a tea retailer's account. One roast takes 8 to 12 hours; several total up to 36 hours.
- Hojicha times
- Hojicha roasting ran from 40 to 420 seconds in the Ishikawa trial.
- Black tea drying
- That black tea is dried with high-temperature hot air comes from The Tea Crane.
- Two tea farms
- Senrei, in Kamikawa, Hyogo, roasts summer-picked black tea. Makinohara Yamamotoen roasts Benifuuki hard and describes a peach-and-grape aroma.
- Shifting aroma
- A 2022 report on roasting Wuyi rock tea states that the roasted aroma shifts towards a floral one during storage.