OCR Text |
Show Colors of Grapes. The dark-red color of certain grapes' is due to a compound of tannin which all varieties of the vine contain. The color seems to depend on the combined com-bined action of the air, light and heat. The change in color Is produced naturally nat-urally in the vine by means of a specific spe-cific ferment whiph carries the oxygen oxy-gen of the air to the grape. These lerments are often the agents of coloring col-oring in vegetable substances, as they are often seen In apples and In potatoes pota-toes which have been cut open and thus exposed to contact with the air. The grapes that are white on maturity matur-ity owe the absence of coloring to the absence of this ferment. Harper's Weekly. |