On the scale, 2.3 g of leaf: the amount per 100 mL of water when the composition tables measured hojicha infusion [calculated; 2.31 rounded]. Beside it, 16.7 g of gyokuro fills a small dish. Level the water at 100 mL and set them together: under the same word, leaf, one is a pinch and the other a handful.
Can figures measured under different conditions be laid out for comparison?
Two ways. Take only what was measured under identical conditions, or convert to a per-gram-of-leaf basis. Either way, hojicha stays towards the top of the table.
Two groups were measured under identical conditions
In the 2023 supplement to the eighth revised edition, two groups were measured under exactly the same conditions. One runs on hojicha's own conditions (15 g of leaf, 650 mL of water at 90°C, 0.5 minutes): bancha, hojicha, genmaicha and oolong tea. The other on sencha's (10 g of leaf, 430 mL at 90°C, 1 minute): sencha and kamairicha. Published values compare as they stand only inside each group.
In the group of four: bancha 10 mg and genmaicha 10 mg against hojicha 20 mg and oolong tea 20 mg. In the other: sencha 20 mg against kamairicha 10 mg. On the table, hojicha sits on the higher side (figure below).
At the precision of the composition tables, the two cannot be told apart
The thing to watch is the number of places. The values in this column run to two decimal places, too coarse for the gap between 10 mg and 20 mg to be read as “twice”. For the same reason, hojicha and sencha cannot be called equal either. What can be written is this: at the precision of the composition tables, the two cannot be told apart.
Converting to a per-gram-of-leaf basis
Gyokuro's 160 mg is eight times hojicha's 20 mg. The leaf going into 100 mL of water, though, is 7.2 times as much [calculated]. Per gram of leaf, the eightfold gap shrinks to about 1.1 times (table below). Gyokuro comes out strong because it is brewed strong.
Figure 1-2-2Infusion conditions, published values and per-gram-of-leaf figures by type of tea
| Type of tea | Infusion conditions (g of leaf, water temperature, mL of water, time) | Leaf per 100 mL of water [calculated] | Caffeine per 100 mL of infusion (published, mg) | Per gram of leaf [calculated] |
|---|---|---|---|---|
| Gyokuro | 10 g of leaf・60°C・60 mL・2.5 min | 16.7 g | 160 | 9.6 mg |
| Sencha | 10 g of leaf・90°C・430 mL・1 min | 2.33 g | 20 | 8.6 mg |
| Kamairicha | 10 g of leaf・90°C・430 mL・1 min | 2.33 g | 10 | 4.3 mg |
| Bancha | 15 g of leaf・90°C・650 mL・0.5 min | 2.31 g | 10 | 4.3 mg |
| Hojicha | 15 g of leaf・90°C・650 mL・0.5 min | 2.31 g | 20 | 8.7 mg |
| Genmaicha | 15 g of leaf・90°C・650 mL・0.5 min | 2.31 g | 10 | 4.3 mg |
| Oolong tea | 15 g of leaf・90°C・650 mL・0.5 min | 2.31 g | 20 | 8.7 mg |
| Black tea | 5 g of leaf・boiling water 360 mL・1.5–4 min | 1.39 g | 30 | 21.6 mg |
The value for the leaf itself is the lowest on the list
Values for the leaf itself are in the 2023 supplement too. Hojicha leaf is 1.5 g per 100 g — the lowest on a list that runs gyokuro 3.5, matcha 3.2, black tea 2.9, sencha 2.3, bancha 1.9. Low as a leaf, level with sencha once brewed: both hold at once. What cannot be done is divide the leaf value by the infusion value for an extraction rate. The national table does not say the two were measured on the same sample.