In ‘From Field to Factory’, we told you all about the activity that takes place in the tea garden where the leaves are picked. Now, let’s look at the five key processes which ensure those leaves will taste great in the cup.

Withering

Withering is a process by which the quantity of water or moisture content in the tea leaf is reduced from 100% to 65-70%. Leaves brought in from the field are immediately spread out on clean withering troughs and the fans are switched on. Depending on the direction of the atmospheric wind, the Head Tea Babu will change the direction of the withering troughs’ wind flow. During the withering process, food handlers shuffle the leaves – moving the bottom ones to the top and vice versa – to ensure a consistent wither. Uneven wither will cause inconsistent quality in the final product.

Rolling

At regular intervals the Head Tea Babu will ascertain whether the required withering has been achieved. Once he gives the go ahead, the leaves are sent for rolling, when making ‘orthodox’ teas like loose leaf, or the Crush Tear Curl (CTC) process for tea bag teas. For CTC teas, the leaves are crushed and torn by sharp rollers rotating at high speed, and then put through a rotating tunnel which gives the teas the granular quality needed for tea bags. In the case of rolling, the leaves are rolled under pressure on a rolling table, with the Tea Babu deciding the pressure. It is during this process that tea leaves take on a twisted, curly look. During the rolling, the cells of the leaves are broken and exposed to atmospheric air, which initiates the process of oxidisation, or fermentation, which follows.

Oxidising

To allow the full cup character of black tea to develop, the leaves are taken for oxidisation. This takes place in a room where the ambient temperature is kept cooler with the use of humidification fans, and rolled tea leaves are laid out in batches. Depending on the ambient temperature the process could take an hour or longer. During this process the tea picks up a distinct sweet character, and the colour changes from green to a light coppery brown. 

Drying

The Head Tea Babu will decide if the tea has attained its peak fermentation and should be sent for drying and baking. Fermenting any longer will cause a decline in quality – it is therefore important that the tea is dried at the right temperature and at the right time. Overdrying will remove the tea’s delicate flavour and could make it unpalatable, so the Tea Babu has to keep a close eye on the drying process as well. By the time the tea has been dropped from the drying oven, the moisture of the leaf has reduced from 100% when plucked to below 3%. 

Sorting

After drying, the teas are carefully put through sorting machines containing sieving meshes which segregate the tea into various sizes. Finally, after sorting, the teas are packed in paper sacks or wooden chests and despatched around the globe, ready for the next step of the process.

Part 1: From Field to Factory