304 ANNUAL OP SCIENTIFIC DISCOVERY 



GREEN TEA, HOW COLORED. 



A FOREIGN correspondent of the London Alhen&um, of Aug. 4, fur- 

 nishes the following information concerning the mode of coloring green 

 teas as practised by the Chinese in the celebrated tea-growing district of 

 Wheychow. The writer, accompanied by an excellent interpreter, was 

 favored with an opportunity of witnessing the whole process, the details 

 of which were noted down with great care. 



The superintendent of the tea-makers managed the coloring part of 

 the business himself. In the first place, he procured a portion of indigo, 

 which he threw into a porcelain bowl not unlike a chemist's mortar, 

 and crushed it to a fine powder. He then burned a quantity of gypsum 

 in the charcoal fires which were roasting the tea. The object of this 

 was to soften the gypsum, in order that it might easily be pounded 

 into a fine powder, in the same manner as the indigo had been. When 

 taken from the fire it readily crumbled down, and was reduced to a 

 powder in the mortar. These two substances, having been thus pre- 

 pared, were mixed up in the proportion of four parts of gypsum to 

 three of indigo, and together formed a light blue powder, which in 

 this state was ready for use. This coloring matter was applied to the 

 tea during the last process of roasting. The Chinese manufacturer 

 having no watch to guide him uses a joss stick to regulate his move- 

 ments in regard to time. He knows exactly how long the joss stick 

 burns, and it of course answers the purpose of a watch. About five 

 minutes before the tea was taken out of the pans the superintendent 

 took a small porcelain spoon and lifted out a portion of the coloring 

 matter from the basin, and scattered it over the tea in the first pan ; he 

 then did the same with the rest, and the workmen turned the leaves 

 rapidly round with their hands in order that the color might be well 

 diffused. During this operation the hands of the men at the pans be- 

 came quite blue. 



The writer took some trouble to ascertain precisely the quantity of 

 coloring matter used in the process of dyeing green teas, and he found 

 that to 14 pounds of tea rather more than an ounce of this indigo and 

 gypsum mixture was applied. So that for every hundred pounds of 

 green tea, which are consumed in England or America, the consumer 

 really introduces into his stomach more than half a pound of this dele- 

 terious dye, which there is little doubt often has Prussian blue substi- 

 tuted in it for the indigo. 



In five minutes from the time that the coloring substance was 

 thrown into the pans the desired effect was produced. Before the tea 

 was removed, however, the superintendent took a tray and placed a 

 handful from each pan upon it, and these he examined to see if they 

 were uniform in color, and if the examination was satisfactory he 

 gave the order to remove the tea from the pans, as the process was 

 complete. But sometimes it happened that there was a slight differ- 

 ence in the color of the samples, and in this case it was necessary to 

 add more dye, and therefore to keep the tea a little longer in the 

 pan. 



On being asked their reasons for thus dyeing their teas, the China- 



