Everything You Should Know About Green Tea

5 Mins
August 9, 2017

Hello! I am Bezalel Adainoo, the author of Stay Well Now. My friends call me Bez. As a professional food scientist, I have been asked many questions by people from different walks of life seeking the right information on what food to eat and how that will affect their health.

Tea is a beverage full of aromatic compounds which have a strong impact on the flavour, taste and appearance on the beverage. Originating from Asia, China to be specific, it has permeated many cultures around the globe through trade and cosmopolitan lifestyles. Now, everywhere you go, people are having tea for breakfast or have a tea break on their schedules. There are many types of tea. Among these many types, green tea has gained popularity for its link with certain health benefits which will be examined thoroughly in this post.

How green tea is made

Interestingly, all tea is made from the same plant called the tea plant or tea shrubs. What sets green tea apart from the other types of tea is how much air (oxygen) the leaves absorb during its making; green tea is not allowed to take up as much oxygen as the other types of tea take up.

Also, the delicate flavours of green tea are strongly influenced by how it’s made. By how green tea is made alone, several flavours can be incorporated into it yielding different types of green tea.

To make green tea, leaves from the tea plant are steamed at temperatures above 71°C. This step is crucial to killing bacteria and maintaining the green colour of the leaves. Steaming the leaves also ensures fermentation doesn’t occur, that is why green tea lacks the richer taste black tea has. The steamed leaves are then fired to dry separately or they may then be rolled into small pellets and dried over the the source of heat (normally, fire) till they are crisp. At this point, the tea is still green. It is then packaged while containing less than 3% water content, which is also important for the prevention of fermentation or spoilage of the packaged tea.

The best way to brew green tea

The quality of the water used to brew tea is essential to the quality of the tea. So, it is said that the better the water, the better the tea. Water from different sources has different properties. These distinct properties have a direct effect on the taste and flavour of green tea. This is why green tea aficionados are very particular about the kind of water they use to brew their tea. Tap water very often contains mineral additives like fluorine and some dissolved minerals from metal pipes which could add metallic flavours to your green tea. Spring water has the right properties for brewing green tea. Alternatively, using a home filtration system to treat water that is normally hard will produce good water quality for good quality green tea.

The temperature of the water used to brew green tea is very important. Freshly boiled water is best, but, if the water is too hot, much of the green tea’s aroma will be lost and it will also be very bitter. Generally, the best green tea quality is obtained when the tea is brewed at temperatures between 60°C and 85°C. It may be a bit difficult to tell the temperature of the water you’re using if you don’t have a thermometer to check the temperature. Following the steps listed below will help you to get the ideal temperature for brewing your tea.

  1. Boil water in a kettle
  2. Pour the water from the kettle into a Pyrex cup and allow it to sit for 3-4 minutes. This will help you reach a temperature of about 75°C - 65°C. Alternatively, you could pour the water from the kettle into a cool glass or ceramic cup and pour back and forth
  3. Transfer the water into a teapot and brew the tea for the desired length of time (ideally, 2 – 3 minutes).

NB.: How long you steep the tea in the water will determine whether or not the tea will be bitter and whether or not the tea will have the best flavour balance. The temperature of the water should be matched with the length of time for brewing. Low water temperature would require longer brewing time than high water temperature.

The composition of green tea

Green tea is filled with several antioxidants and contains almost no calories at all when unsweetened. When brewed, a cup of unsweetened green tea (and every other tea) is about 99.5 – 99.9% water. The other 0.1 – 0.5% is made of vitamins, flavour compounds, caffeine, minerals and antioxidants.

Vitamins in green tea include vitamins A, B5, B7 (also known as vitamin H), C, D, E and K. Green tea also contains magnesium, manganese, iron, potassium and sodium.  Nevertheless, the quantities of these vitamins and minerals are too small for green tea to be considered a good source of these vitamins just like in the case of honey.

[Related: Everything you need to know about honey and some facts will shock you]

Green tea contains caffeine as well, though its caffeine content is not as high as it is black tea, coffee and other sources of caffeine. However, at high doses of green tea, the effect of caffeine on a person’s health could be significant. The stimulation effect of caffeine may be mild. Hence, it is advised that pregnant women, breastfeeding women and people with conditions such as heart-related diseases should avoid green tea. This is because the effect of the caffeine may aggravate their sensitive health conditions. There are also some green tea products whose caffeine contents have been reduced by some processing methods (decaffeinated green tea or decaf green tea).

The antioxidant properties of green tea are conferred on the beverage mainly by the polyphenols. The vitamins C and E in green tea also contribute to its antioxidant properties, but to a limited extent. The consumption of these polyphenols is associated with a reduced risk of cancer, inflammations and heart diseases. Also, these polyphenols have been found to prevent the harmful effects of radiations. Can we conclude that consumption of green tea is directly responsible for all the health benefits it is touted for?

Is green tea as healthy as they say?

It has been reported that green tea is effective in assisting with weight loss and treating conditions like cancer, high blood cholesterol, tooth decay, high blood pressure, etc. But are there evidence to support these claims? Let’s take a look at these popular claims.

Caffeine and catechins in green tea are the two components which have a strong impact on the burning of calories (or energy expenditure). Meaning by drinking green tea, you’re going to burn calories and thereby lose weight. However, a study aimed at assessing the efficacy and safety of green tea for weight loss and weight management in overweight and obese adults found the something different. It was found that there were some slight weight losses among the subjects of the study. But the weight loss wasn’t significant. A similar observation was made of the effect of green tea on weight management.

[Related: 4 simple ways to manage your weight in your kitchen]

On cancer, green tea has been suggested in some studies to protect against breast cancer, prostate cancer and colorectal cancer. Yet, a more recent review of studies linking green tea and cancer concluded that the proof for green tea curing cancer is scanty to say green tea prevents or treats cancer.

Among the health claims, the only one that has quite sufficient evidence to support is the effect of green tea on blood cholesterol level. A 2013 review concluded that green tea reduces LDL cholesterol in the blood, though the reduction in LDL cholesterol is short-term.

[Related: Everything you need to know about cholesterol]

Green tea is a safe refreshing beverage you can drink to re-hydrate your body. It contains some vitamins, minerals, antioxidants and caffeine. The caffeine in green tea is not so high but people with sensitive health conditions are advised to stay away from green tea or such people may choose the decaf green tea. 

[Related: Exercise and water what you need to know ]

There are no conclusive evidence supporting most of the health claims associated with green tea. However, you may continue to enjoy green tea as a rehydrating beverage.

Have you had some tangible benefits from drinking green tea? Share your experience or that of someone you know in the comment section. Let the discussion continue on health benefits of green tea continue. Also if you found this helpful share this with friends and family to keep them also informed.