Editors Note: This plantation is at a lower altitude than a number of other Darjeeling plantations. Processing times and activity lengths can vary from factory to factory, especially given higher altitudes have less oxygen in the air. Oxygen is necessary for oxidation to occur — the process may take longer at higher altitudes. Also, the withering process takes longer in colder temperatures, so higher elevation factories could be affected more likely than those below.
The process will change depending on the season. Later seasons harvest require longer processing time.
The most important things in black tea are withering and oxidizing the leaf.
Mar 25th, 2018: One of the purposes for my travel is to get a better understanding of how my teas are produced. I want to know exactly what goes into creating that delicious brew in my cup. And in doing so, I created Tea The World (@TeaTheWorld) to document this journey and share it all with you!
Well, this week I had the very fortunate opportunity to get a behind the scenes look at the production process for Darjeeling tea. I was visiting the Longview Tea Estate and they granted me behind the scenes access to their factory and expansive fields so that I might get a better understanding of exactly what goes into making Darjeeling tea.
The process starts in the field where the pluckers handpick the leaves from the top of the tea bush (tea table). When plucking they look for the soft and supple leafs, which are a light green color at the top of the bush. Looking at the bush, it is easier than I would have thought to see what you want to pick — there is a noticeable difference between the new leaves and that of the base of the tea table (a darker forest green color).
After the leaves are plucked, they are brought to a central spot where the bags of leaf are weighed and recorded. From there they are collected in larger bags, placed in the back of a tractor, and transported to the nearby factory. I was told that this process takes place at three different times each day.
Once the tractor reaches the factory, the bags of leaves are taken inside the “withering room.” In this room there were four giant trough like structures (I later discovered that there were four additional troughs on the other side). These troughs are about 60-75 feet in length and 4-5 feed in width. Looking inside the trough, there is a recessed metal screen which the leaves rest on as they are withering. The leaves are spread out evenly over the trough at a 2-3 inch thickness. From there, a large blower fan at one end of the trough is turned on pushing air into the cavity underneath the screen and the air is pushed upwards through the leaves causing them to dry.
The withering step lasts approximately 16-20 hours. The objective is to reduce the moisture content in the leaves to 40%.
Once the leaves reach a ~40% moisture content, they are again collected in giant bags and taken off to be loaded into a giant machine called a rolling table machine. The rolling table machines in this factory are located on a lower floor, so the leaves are pushed through a medium sized hole in the ground. This hole feeds into a long shoot where at the bottom someone is waiting to feed the leaves into the rolling table machine.
The leaves will remain in the rolling table machine for approximately 4-5 minutes. The objective of this step is to break the cell wall of the leaf causing the oxidation process to start to occur.
After the 4-5 minutes required in the previous step the leaves are spread out on the ground (its a clean surface) exposing them to as much air as possible and the oxidation process begins. (This process is referred to here as fermentation — from everything I have seen and read, this is not an uncommon reference in Asia.) The leaves will then be in this state of oxidation for approximately 4-6 minutes.
** Quick note: I witnessed the process for the First Flush of Darjeeling tea. The factory manager informed me that the 2nd – 4th flushes require longer oxidation (fermentation) periods ranging from 30 minutes to 2:30 hours. This will also vary based upon the elevation of the factory — higher elevation = less oxygen in the air, lower elevation = more oxygen in the air.
The leaves are then collected after the 4-6 minutes are up and loaded into a large drying machine. Think of this as a giant oven, say the size of a small RV/Motorhome with a multiple levels of conveyer belt twisting around on the inside. There are blowers pushing hot air into the drying machine at a temperature of roughly 115-118 degrees celsius (239 – 245 F) and coming out at about 75 degrees celsius (167 F). This heat will stop the oxidation process.
23 minutes later, the leaf will come out dried… and will now be considered “made tea”.
From there the leaf was moved on to the sorting and grading step. This is done via a three step process.
The leaf coming off the line will be placed on a large vibrating table-like machine called an Middleton Machine. This machine is designed to separate the overly large leaf from the batch. This “overly large” leaf will then be taken to a “Breaker Machine” which is designed to do exactly what its name suggest, break the dried leaf into a smaller size. It will then be placed back upon the Middleton sorting machine.
If the leaf is the right size, it will fall through the screen onto a conveyer belt where it will be fed into the final machine, the “Arnott” machine. This machine is designed to pick up any metallic elements via a giant and powerful magnet that may have been inadvertently introduced via any of the steps previously. The leaf passes under this magnet and any metallic elements are collected. (I will admit this surprised me to learn, but given the use of all of this metal machinery, I guess it is realistic that metal could somehow end up in the the batch — it acts as a safeguard.)
The leaf is then again sorted on this machine via and additional “grader” screen which will separate the larger leaf (the best grade), the medium/small leaf (the secondary grade), and the fannings/tiny leaf particles (lowest grade — used for teabags). There are three different places on this machine where the three different grades of leaf come out and fall into the collection bags below.
The last step of production is the packaging. Here the leaf is sorted into 20 kg bags where it will then be sold to a buyer. The buyer will then decide how to package it in smaller batches and sell to the broader public.
The FINAL and most important step is when you get it home and brew it in your cup: enjoyment.
There you have it.. the complete process from plant to cup for Darjeeling tea.