Littell's Living Age/Volume 130/Issue 1673/Miscellany

The Quantity of Tannin in Tea. — This question has been, with many others in relation to the chemistry of this plant, gone into by Mr. T. Wigner, whose papers have been published in the Chemical News. The number of the C. N. for Nov, 12, 1875, contains the author's remarks on the tannin question. He says that the percentage of tannin in tea is very variable, and there is little doubt that this is in a great degree the cause of the erroneous estimate which English tea-drinkers frequently make of the dietetic value of tea. They prefer tea which gives a dark-coloured infusion, and has some sensible astringency, to those varieties which give a paler and less bitter liquor. This probably accounts, to some extent, for the high estimation in which some kinds of Assam are held for mixing-purposes. The acetate-of-lead process seems more reliable for determining the percentage of tannin than the old gelatine process, and it is certainly easier. I have therefore adopted it. I find that a sample taken from a mixture of six samples of Assam tea gave 45.5 per cent, of tannin, while some of the highest results were —

Per Cent
No. 82.	Moyune young Hyson	30.0
No. 83.	Very choice Assam	32.0
No. 1.	Indian young Hyson	39.0
No. 97.	Assam tea from Dr. McNamara's garden	27.7
No. 75.	Caper (mixed)	42.3

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