What is the difference between green and black tea? To begin with nothing at all, both come from the same camellia sinesis bush. However it is how the tea is then processed which creates the difference.
After plucking and undergoing partial withering, green tea is heated almost immediately at about 200 degrees Celsius to prevent fermentation. The tea is then rolled to give it shape before being heated again. In contrast, black tea is processed in a different order: it is withered then rolled before any heating takes place. The tea is then left to ferment for some time where it takes on the brown/black colour and develops its flavour before being heated again to stop the process.
It is therefore the fermentation reaction that causes the key differences between the two types of tea. Both types of tea contain high levels of polyphenolic antioxidant compounds. In green tea these are mainly catechins. In contrast, the fermentation of black tea causes enzymes to convert these catechins to therabugins and theaflavins.
