Andrade Peptone Water w/ HiVeg™ Extract No. 1 is a basal medium for studying fermentation reactions, particularly of members of the Enterobacteriaceae. This medium is the most commonly used media for carbohydrate fermentation. Desired carbohydrate is added to the medium, which is inoculated with the test organism. If the test organism metabolizes the added carbohydrate, acids are produced, thereby lowering the pH of the medium. This causes a subsequent colour change of the indicator, from colourless to pink to red. If the added carbohydrate is not metabolized, the medium remains pale tan to straw coloured. Gas produced during fermentation is collected in the Durhams tube.