In the pan, warmed sand shifts and folds around the leaf. One tea merchant's record tells of looking for a new way to roast that would keep the taste of sand roasting. An old report on firing machines records another idea: far-infrared heat and hot air in one machine.
What follows reads the two records not as one story running from old tools to new, but through the problem each was trying to solve.
Keeping the taste, not the sand
A dry, toasted smell rises from a sand-roasting pan. What the merchant wanted to keep was not the sand itself but that taste.
An old merchant's company history recalls a time when concern about food safety was rising. It says the company looked for a roasting method that kept the taste of sand roasting without sand getting into the tea. The aim was neither simply to stop using sand nor simply to protect the old tool.
What it wanted to keep was the taste; what it wanted to reduce was the chance of sand in the tea. The record supports only what the company history says. After the sand comes a machine sending heat from above and below.
Infrared above, air below
Leaf travels slowly along a long trough. That firing machine combines two kinds of heat in one unit: far-infrared from above, hot air from below.
An old report in tea research describes a far-infrared firing machine developed by a machine maker. Far-infrared heaters sit above a trough that carries the tea, and hot air is sent up from beneath. Read as a choice between far-infrared and hot air, this design is easy to miss.
The report, though, concerns the final firing of green tea, not a trial in making hojicha. That is as far as the record goes. After the two records comes the question of joining them.
Two records, left unjoined
Set the two documents side by side on a desk and the urge is to draw a line between them by date. These two, though, do not join into one lineage.
The company history and the firing-machine report each record a separate effort. These two alone do not show that one technology passed directly into the other. Join cause to effect by similar words or the order of dates alone, and the history of a technology easily becomes a different story.
The year in the report is when it was published, not necessarily when the machine was born. The record supports only when things were written down. After the records comes the problem a tool solved.
The problem a tool solved
List old roasting machines by name in order and it starts to look like a timeline. The history of roasting, though, is a record of deciding what to change and what to keep.
Keeping the taste while keeping sand out; combining two ways of delivering heat in one machine. Seen from the problem, the reasons tools changed come into view. Company histories and machine descriptions sometimes set down what was troubling people, what mechanism changed, and what taste they meant to keep.
The method names printed on today's packets may hold background that has never been explained. The record supports only what these two documents say. The years and names are gathered below.
The numbers in detail
- The company history
- Maruhachi Seichajo, “From sand roasting to a new roasting method”.
- When
- the Showa 40s (1965–1974), as concern about food safety grew. The company looked for a roasting method that kept the taste of sand roasting without sand getting in.
- The report
- a 1988 report from the Japanese Society of Tea Science.
- The machine's maker
- the far-infrared firing machine in the report was developed by Shizuoka Kikai Seisakusho.
- The design
- far-infrared heaters above a trough conveyor, with hot air sent from below.
- Reading the year
- 1988 is the year the report was published, not necessarily the year of development or release.
- The report's scope
- it deals with the final firing of green tea, not a trial in making hojicha.