“Experimentally it is found that infusions of tea and coffee are strong enough when the former contains 0·6 per cent. of extractive matter, and the latter 3 per cent., so that a moderate-sized cup (5 oz.) should contain about 13 grains of the extract of tea, or 66 grains of coffee. These proportions will be obtained when 263 grains of tea (about 21⁄2 teaspoonfuls) or 2 oz. of freshly-roasted coffee are infused in a pint of boiling water; and the amounts of the several constituents dissolved are about as follows:—
| “Constituents. | Tea. grs. | Coffee. grs. |
| Nitrogenous matters | 17·2 | 44·0 |
| Fatty matter | — | 3·0 |
| Gum, sugar, and extractive | 31·7 | 103·2 |
| Mineral matters | 9·1 | 22·8 |
| ——— | ——— | |
| Total extracted | 58·8 | 173·0 |
“So that tea yields, to a pint of fresh water, about 22 per cent. of its weight, and coffee about 20 per cent. Lehmann found that only 151⁄2 per cent. of tea was dissolved by water, whereas Sir Humphry Davy estimated it at 331⁄2 per cent. No doubt the quality of the water, as well as that of the tea, affects the results, for cold distilled water will extract from 40 to 44 per cent. of black tea, and nearly 50 per cent. of green; but, for all this, about 22 per cent. is a good average with boiling water.”[226]
[226] Letheby, ‘Lectures on Food.’ Longmans.
Dr Edward Smith has shown in the following table that, when the usual custom of measuring tea into the teapot by the spoonful is followed, very varying weights of tea are employed. Thus he found that the weight of a spoonful of tea was for—
Black Teas.
| Oolong | 39 | grains. |
| Congou (inferior) | 52 | ” |
| Flowery Pekoe | 62 | ” |
| Souchong | 70 | ” |
| Congou (fine) | 87 | ” |
Green Teas.
| Hyson | 66 | grains. |
| Twankay | 70 | ” |
| Fine Imperial | 90 | ” |
| Scented Caper | 103 | ” |
| Fine Gunpowder | 123 | ” |
The attempt to make good tea will prove a failure unless the water employed is boiling. Previously to making the infusion, the teapot should always be warmed up by means of boiling water. The kettle should be filled from the tap, and not the boiler. It should also be borne in mind that neither good tea nor coffee can be obtained if they are made with water that has been in the kettle for many hours. The tea is ready to be drank after the boiling water has stood on it for five minutes.