The oxidation process determines the tea's colour, taste and strength.
First, the leaves are put in troughs or laid out on tables. Then, they're left for between 30 minutes and two hours, at a temperature of about 26°C.
During this time, enzymes inside the leaves react with the air around them, changing the leaves' colour from green to beige, to a rich, deep brown. The colour indicates how oxidised the tea is and what its flavour will be like. To make a tea with a lighter taste, the oxidation process is stopped when the leaves are light brown. For a stronger tea, the leaves will remain in the warmth until they're rich and coppery.
Drying or firing
Once the leaves have been oxidised to the right level, they're passed through hot air dryers. This further reduces their water content to about 3%, leaving them ready to be sorted and packed