Black Tea 101

Tea Of The Empire

Black tea was developed in the 1500’s as a method of extending the shelf life of tea. Black tea’s predecessors, green and white tea, were not suited to withstand the long journey from China, and later India, to European nations.  In China, black tea is often referred to as “red” tea for the amber color of liquor produced when brewed.

Black tea was a favorite of the British Empire and is the most commonly consumed tea in North America.  It’s also the brew of choice for iced, mixed, and chai teas, as well as favorites such as Earl Grey and English Breakfast. The development of black tea created new flavors and unlocked higher levels of caffeine and medicinal compounds like theobromine (which in high levels is used as a bronchodilator in asthmatic medicine). When brewed, black tea produces a dark olive-brown liquor with muscatel-woody notes and is moderately high in caffeine.

Production

Like white, green, and oolong teas, black tea is a product of the camellia sinensis plant and undergoes a high amount of oxidation. Oxidation is important in the formation of many taste and aromatic compounds, which give a tea its color, strength, and flavor.  Depending on the type of tea desired, under or over-oxidation can result in grassy flavors, or overly thick winey flavors.  (Oxidation is how an apple changes color when the flesh is exposed to air.)

The four notable stages of black tea processing are: withering, rolling, controlled oxidation, and drying. The extent of each of these steps varies by region and by producer preferences. The variation or alteration of each step can produce distinctly different tea flavors and textures.

(Shades of black tea left to right: Assam, Darjeeling, and Turkish)

Withering:

After picking, the leaves are spread out bamboo mats and left to wither until water content has been reduced by 50-70%. This process occurs by the natural circulation of air and can take place outside in sunlight or indoors.  

Rolling:

After withering, a rolling machine lightly breaks the leaves, triggering the release of enzymes to promote oxidation.  

Controlled oxidation:

The broken leaves are then laid out for 1-2 hours to oxidize where the tea is carefully watched to maintain a ratio of theaflavins and thearubigins of around 1:10 to 1:121.  

In the final stage of drying, the leaves’ color changes from brown to black.

Note: One misnomer of black tea production to take into account is that black tea is often referenced as “fully oxidized tea”.  This term is incorrect, the oxidation of black tea is a highly controlled process.  Fully oxidized tea, in reality, would more appropriately be termed as stale tea.

Brewing
On average, black teas are brewed at higher temperatures than white, green, or oolong teas.  The rule of thumb is to brew black tea at 210°F for 2-3 minutes.  Depending on the cut of the leaf and the level of processing, however, the brew time may be longer.  For example, chai teas (black tea mixed with spices) are traditionally boiled in milkfor 5-10 minutes.

Health Benefits

Cardiovascular health

Regulation of blood sugar

Improved circulation

Stress reducer

A good source of antioxidants

Trending Scientific Research

- Black tea consumption reduces total and LDL cholesterol in mildly hypercholesterolemic adults.

- Black tea soothes away stress

- The effects of tea on psychophysiological stress responsivity and post-stress recovery: a randomised double- blind trial

 References

1) Spiller, Gene A. Caffeine. Boca Raton, FL: CRC P, 1998. 47.