<Tr> <Td_colspan="2"> <P> Brassica oleracea Capitata Group </P> </Td> </Tr> <P> Brassica oleracea Capitata Group </P> <P> The red cabbage (purple - leaved varieties of Brassica oleracea Capitata Group) is a kind of cabbage, also known as purple cabbage, red kraut, or blue kraut after preparation . Its leaves are coloured dark red / purple . However, the plant changes its colour according to the pH value of the soil, due to a pigment belonging to anthocyanins . In acidic soils, the leaves grow more reddish, in neutral soils they will grow more purple, while an alkaline soil will produce rather greenish - yellow coloured cabbages . This explains the fact that the same plant is known by different colours in various regions . Furthermore, the juice of red cabbage can be used as a home - made pH indicator, turning red in acid and green / yellow in basic solutions . It can be found in Northern Europe, throughout the Americas, in China and especially in Africa . On cooking, red cabbage will normally turn blue . To retain the red colour it is necessary to add vinegar or acidic fruit to the pot . </P> <P> Red cabbage needs well fertilized soil and sufficient humidity to grow . It is a seasonal plant which is seeded in spring and harvested in late fall . Red cabbage is a better keeper than its "white" relatives and does not need to be converted to sauerkraut to last the winter . </P>

Colour of red cabbage in acid and base