tea and tisane
What is “tea”?
The definition of “tea” is a hot or cold drink made by infusing the dried leaves or mixing leaf powder of the tea plant, Camelia Sinensis, in water. These “teas” include white tea, green tea, oolong tea, black tea, and pu’er tea. These varieties are created from the same plant, Camelia Sinensis. We’ll talk about what makes the different color, aroma, and flavors in these teas later.
What is “tisane”?
Camelia Sinensis produces green tea leaves which contain caffeine. Many people consider the amount of caffeine intake and look for alternatives. These alternatives are called “Tisanes (tih-zann)”, a French word for “herbal infusion”. Probably the term “herbal teas” is more familiar to many people, instead of “Tisanes”.
- Herbal teas: These teas can be made of botanical elements; leaves, stems, roots, flowers, and/or fruits. Popular herbal teas include Chamomile, Peppermint, Tulsi, etc.
- Rooibos teas: South African native teas. Naturally caffeine free. This red tea offers naturally rich, earthy yet sweet aroma, and blends well with milk and various flavors.
- Yerba mate: South American origin and contains caffeine.
*Difference between fermentation and oxidation in tea making
The term “tea” is technically used for drinks made with a plant called Camelia Sinensis. White tea, green tea, oolong tea, black tea, and pu’er tea are made from the same plant. When you taste each tea’s own characteristic aroma and flavor, it’s hard to imagine all these teas are made from the same bush.
Many conditions during the tea production process contribute to forming the distinctive flavor and aroma in the tea leaves. Fermentation as it is commonly called in the tea industry, or oxidation, is one of the main elements.
The degree of the process is used to categorize teas, such as white tea, green tea, oolong tea, and black tea, in the order of the duration of the fermentation process. Pu’er tea uses a different process of fermentation.
Some of you may say, “You should say “oxidation” not “fermentation,” thinking of the process making beer, wine, etc., in which the sugars are converted to ethyl alcohol, and the chemical breakdown of a substance is caused by bacteria, yeasts, or other microorganisms in the absence of oxygen.
When it comes to tea, “fermentation” doesn’t use microorganisms, except for making pu’er. So, is it wrong to call it ‘fermentation’ but rather, should we call it ‘oxidation’?
The short answer is both, ‘fermentation’ and ‘oxidation’, are correct. However, both terms can use a little further clarification.
Fermentation caused by enzyme
According to Merriam Webster dictionary, the broad definition of fermentation is an enzymatically controlled transformation of an organic compound.
Tea fermentation involves the enzyme called polyphenol oxidase (polyphenol oxidase). This enzyme breaks down catechins in the tea leaf into theaflavins and thearubigins.
Oxidation caused in an organized manner
Even without enzymes, oxidation occurs. However, if leaves are left alone, the “oxidation” doesn’t create a good aroma, but causes a rotten odor, instead. Without deliberate and experienced control of moisture, air, and temperature, the oxidation induces degradation, and creates “decayed leaves.” Only with specific conditions carefully controlled, do the leaves become “tea leaves” that offer wonderful aroma and taste.
After teas are “fermented with enzyme” or “oxidized in controlled conditions”, they can also be “aged”. We’ll talk about that in a separate article.