Depending on which study you read and whose analysis you accept as true, the amount of caffeine in your teacup can vary greatly or not at all. Nevertheless, several constants do exist that affect the stimulant intensity of our cups of tea.
CAFFEINE CONSTANTS SPECIFIC TO THE FRESH LEAF
The caffeine content of fresh leaf manufactured into the different classes of tea from the same base leaf is theoretically the same, all other conditions being equal. The leaves of all varieties of the Camellia sinensis plant are infused to brew tea. This infusion can be from any of the traditional classes of tea—black, oolong, green, and white, or such minor manufactures as jasmine. An example of this would be a tippy black tea and a budset spring green tea, both made from the same Camellia sinensis plantings in Yunnan Province, picked during the same season, and then manufactured into their respective tea styles.
The choice of leaf that is plucked partially determines the caffeine content of that leaf. As with herbs and most flowering plants, the emerging bud (the budset) contains a larger proportion of the lifeblood of a plant than do the other leaves. Therefore the budset of the tea plant has more caffeine. As one moves down the pluck, the amount of caffeine decreases incrementally. Spring green budset teas that have a large amount of “down” (the tea bush’s natural pollen) still clinging to them may have an additional source of caffeine in this down. The down is trapped within the budset and remains dusted on it in the spring, when the bud emerges (similar to the green dusty haze released by some conifers). Although it is not scientifically demonstrated in contemporary studies, this influence has been noted in earlier empirical evidence. Any potential variation because of the presence of down varies tremendously from tea to tea, whereas the difference between the budset and the lower leaf is constant.
The age of the plucked leaf has an influence on the amount of caffeine in the leaf. The age of the fresh leaf (the amount of time the leaf has been on the plant) has an effect on the amount of caffeine present. The younger the budset or leaf being plucked, the higher the amount of caffeine, because the “juice” of the plant disperses downward as the plant matures, carrying with it some of the caffeine. The fourth leaf (also known as a coarse plucking) may have 30 percent less caffeine than the same branch’s budset.
The period during the plant’s growth cycle when the leaf is plucked also affects the caffeine content. The amount of caffeine present in the pluck can be influenced by the specific time during the season at which the harvest occurs. Following a hard pruning (for rejuvenation or shaping), severe winterkill, maintenance pruning, or wind damage, for instance, the tea bush is known to increase the amount of nutrient sent to the emerging growth. This also increases the amount of caffeine. This factor is somewhat untraceable but is another variable that may explain why a certain tea may, for no other reason, have a noticeable kick to it. Even prior plucks can increase the caffeine content of leaf picked from the same plant later that season.
REDUCTION OF CAFFEINE BY THE QUICK RINSE METHOD
After thirty seconds of extraction it is reasonable to expect a reduction in the caffeine content of black leaf tea by 50 to 70 percent. This is not decaffeination, as that term implies (and legally requires) the removal of 97 percent or more of the caffeine that was originally present in the leaf. But it is a significant reduction in caffeine and may be enough for those wishing to moderate their caffeine consumption.
Although the speed of extraction from different leaf styles may make a minor difference in this phenomenon, the premise is sound. A good rule of thumb is the same as that used for the steeping times for teas that permit multiple infusions: the greater the surface area exposed, the faster the soluble solids release from the leaf. This caffeine reduction method only works with fully oxidized black tea.
BREWING TECHNIQUES AND THE RELEASE OF CAFFEINE
Different types of tea require different brewing techniques, each of which affects the release of caffeine into the liquid tea. Below are the variables specific to the brewing techniques.
The temperature of the brewing water used affects the amount of caffeine extracted from the tea leaf. One can inadvertently alter the caffeine extraction from the different styles of tea by using water that is either too hot or too cool for the type of tea being brewed. Any such change alters the normal extraction of caffeine usual for that style of tea. Using water that is hotter than is required extracts more caffeine than desired from the tea leaves, and using water that is too cool extracts less caffeine. This variation is most noticeable when brewing green tea.
The amount of time the tea leaf is allowed to brew affects the amount of caffeine in the liquid tea. This is one of the most critical elements of tea brewing. In addition to the goal of correctly brewing one’s cup of tea to develop optimal flavor, the length of steeping time affects the amount of caffeine extracted. It cannot be said whether this is more or less significant when using one style of tea or another. Every style of tea has a specific brewing tradition that should be observed; however, the rate of caffeine extraction relative to the length of time that any particular tea leaf is steeped remains constant, so tea from the same source, steeped according to two different cultural traditions, may vary in caffeine content.
When tea leaves are steeped longer than five minutes, there may be a reduction in stimulant from the brewed tea. This phenomenon is due to one of two reasons: First, the leaf is being brewed multiple times (as with white, green, oolong, and pu-erh teas). As this leaf will have already been infused for a short initial brew or two and the liquor subsequently poured off once or twice (along with the majority of the caffeine), this five-minute marker would only occur during a second, third, or even fourth infusion (for which there is less caffeine remaining to be extracted from the leaf).
Second, if the leaf is being brewed once (most black teas), a long steeping releases many more soluble solids into the brewed tea than does a short steeping. Although the increase in total soluble solids after five minutes likely reduces the percentage of caffeine, the actual amount of caffeine remains constant. There may, however, be other extractives that act as calmatives (for example, the amino acid theanine as well as an abundance of polyphenols, which are proven to bind to caffeine and can prevent absorption) that might negate some of the influence or absorption of the caffeine when consumed. Teabag users who only quickly dunk often extract more caffeine than they realize, because the caffeine extraction rate is very high initially when brewing tea leaves of the size used for most teabags.
Teas that are infused multiple times release varying amounts of caffeine into the different infusions. Green, white, and oolong tea leaves are normally infused multiple times, for a short period (often a maximum of two minutes each) using water that is cooler than that used for brewing black tea. These individual infusions contain varying amounts of caffeine. Different traditions of tea brewing alter the temperature of the water and the brewing time for these individual infusions, but a rough guide to the caffeine content of three infusions of tea brewed from the same green, white, or oolong tea leaves is thus: first brew 60 percent, second brew 30 percent, and third brew 10 percent (of the caffeine originally present in the dry tea leaves). Although the amount of available caffeine in the dry tea leaves varies depending on the type of tea being brewed, the proportion of caffeine in each infusion should remain consistent with this formula.
Taking into consideration all of these variables, it becomes clear that definitive statements regarding the caffeine content of a cup of brewed tea are almost impossible to make. One must first know a great deal of information about the source of the tea (or have a chemical analysis done on the tea leaf), and then adjust for the brewing technique used. Those who quote definitive caffeine contents or comparisons based on traditional, inaccurate assumptions do a disservice to their readers or customers. That being said, if you have a significant amount of information about the tea in your possession, a learned guess can be made as to whether or not that leaf tea will be in the norm or uniquel
y different from the above guidelines. Then the brewed tea can be prepared so that the caffeine present in that brewed tea will be as expected.
As interest in tea has increased, much more information is being provided about the source of the tea leaf being purchased, so making an educated guess about caffeine content is becoming more possible. Retailers who specialize in source-specific estate teas from identified seasonal harvests can be helpful in assessing the caffeine content of their teas. Studies that have been done on the caffeine concentration in already-brewed tea (ready-to-drink, bottled tea) show a significant variation in the available caffeine.
The other notable factor is that it is not what one consumes but what one absorbs, and every individual’s metabolism and capacity to absorb caffeine and the other components of brewed tea accordingly affects the stimulating and healthful properties of leaf tea. Even what one has or hasn’t eaten recently can influence the absorption rate of the components of beverages.
CAFFEINE QUIZ
Which brew probably has more caffeine? The first infusion of a downy budset green tea brewed from the plucking of a China bush plant on an early spring morning, or a cup of black tea brewed five minutes from an orthodox Assam pluck that was picked in late autumn from a bush that was heavily pruned earlier that spring and fed a hefty dose of organic fertilizer just before monsoon season? The constants are that all the brewing is done with two grams of tea and the same amount of water. The answer: it is impossible to know, as there are several factors involved.
If the downy budset green tea has a caffeine content of 4 percent (very high) and 60 percent of the caffeine is extracted during the first infusion: 2000 milligrams × 4 percent × 60 percent = 48 milligrams of caffeine.
If the downy budset green tea has a caffeine content of 3 percent (moderate) and 60 percent of the caffeine is extracted during the first infusion: 2000 milligrams × 3 percent × 60 percent = 36 milligrams of caffeine.
If the downy budset green tea has a caffeine content of 2 percent (very low) and 60 percent of the caffeine is extracted during the first infusion: 2000 milligrams × 2 percent × 60 percent = 24 milligrams of caffeine.
Now let’s assume that the Assam tea has a caffeine content of 4 percent (very high). After five minutes of brewing, it is safe to assume that at least 80 percent of the caffeine will have been transferred to the brew, so the calculation is: 2000 milligrams × 4 percent × 80 percent = 64 milligrams of caffeine.
Now let’s assume that the Assam tea has a caffeine content of 3 percent (moderate). After five minutes of brewing, it is safe to assume that at least 80 percent of the caffeine will have been transferred to the brew, so the calculation is: 2000 milligrams × 3 percent × 80 percent = 48 milligrams of caffeine.
Now let’s assume that the Assam tea has a caffeine content of 2 percent (very low). After five minutes of brewing, it is safe to assume that at least 80 percent of the caffeine will have been transferred to the brew so the calculation is: 2000 milligrams × 2 percent × 80 percent = 32 milligrams of caffeine.
One can see from these analyses that it is possible that the green tea might have 50 percent more caffeine than the black tea, or the black tea might have two and a half times the caffeine of the green tea. There is no practical way of knowing when you sit down to enjoy your cup of tea.
From the believed benefits of ancient times to the demonstrated advantages shown in modern laboratories, drinking tea has proven itself over and over to be a therapeutic life-enhancer. Drink all types of tea, potentially as much as six cups per day. Just remember the advice given by everyone from your mother to Julia Child: eat a varied and balanced diet, with all elements in moderation.
IN THIS CHAPTER WE EXPLORE several of the social and political aspects of tea production and marketing. As with dairy, soy, cattle, cacao, and coffee, tea is a labor-intensive crop to bring to market. Dovetailing with similar movements in other food-producing endeavors, many businesses, individuals, and government agencies are involved in efforts to improve both the transparency of tea distribution and the living and working conditions of those involved in the agricultural production of tea at its source. This chapter examines issues in organic production, fair trade, source identification, and sustainability. We also mention several regulatory organizations and certifying agencies.
Organically Grown Tea
Organic tea production falls into two categories: (1) tea that is certified organic by one of several international agencies, and (2) tea that is grown according to traditional methodology that inevitably follows organic principles but has not been validated by a certifying agent. When a tea is “certified organic,” it has met the conditions set forth by at least one of the regulatory agencies that has established guidelines for organic food production. Only then can the product affix the proper seal and use the appropriate terminology identifying which level of “certified organic” the product has attained. As a general rule, a fee is paid to the certifying agency for this service, and any inspection required is conducted at the time of certification and then repeated periodically. The countries with the strictest organic certification standards are Germany, the United States, Japan, and the United Kingdom; however, the European Union’s Regulation (EEC) No. 2092/91 is the benchmark for the industry.
Though I cannot flee
From the world of corruption,
I can prepare tea
With water from a mountain stream
And put my heart to rest.
—UEDA AKINARI, JAPANESE AUTHOR (1734–1809)
Organic certification was originally conceived as a way that a farmer or merchant could convey that the tea (or other agricultural product) for sale had been grown under time-honored and desirable conditions. It is a validation that became necessary due to the increase of modern farming procedures worldwide, combined with broader distribution of product and differences in standard from origin to origin. Tea that is certified organic today is often inspected and marketed as such because of the potential for a “value-added” economic advantage. Organic certification in the twenty-first century is increasingly the domain of big business and less that of the dedicated back-to-nature types—the rebellious farmers and merchants of the late 1900s. During the agricultural land consolidation years of the 1970s and 1980s in the United States, small farmers of food crops were encouraged to sell their ordinary land to large corporations. Many farmers and landowners whose land qualified for organic certification at the turn of the twenty-first century came under a similar pressure to sell that land to large multinationals, so that those companies could quickly gain organic market share.
Tea gardens are traditionally not owned by small landowners, but rather by large businesses or venerable tea families that provide housing, crop land, and support infrastructure for the garden’s workers. The conversion of the tea gardens to (or the continuation of) organic methodology is thus dictated more by location and the health of the parent company, rather than by the market forces moving most other organic trade. Artisan tea is unique as well, because much of the terrain on which it is produced is at high altitude and remote, and tended by generations of the same families who have been in the same place for decades, even centuries.
In 2000, when we visited the Kai Hua Tea Factory in China’s Zhejiang Province, the largest tea factory in the world, tea was available at any price and every quality. While we toured the facility, we encountered German tea buyers shopping for organic, high-quality specialty tea as well as Sudanese tea buyers looking for some of the cheapest tea on the planet. This is not an atypical scenario, so it is difficult for tea growers to know whether the future market will have as its main criteria quality, organic production, price, flavor profile, or a combination of these elements. In general, tea customers in Canada, the United Kingdom, the United States, Western Europe (Germany in particular), and now members of the emerging middle class in Asia are desirous of drinking high-quality tea, organically grown when possible. For most of the tea-drinking world, however, price
is the major consideration, so cost-ratio will affect any potential increase in organic production worldwide.
When a tea is grown organically simply because of tradition or commitment, it means that the tea has been grown following agricultural principles that have never changed, so this is the traditional and only method known to the tea grower. Organic principles might also be maintained because of location, purposeful dedication, or economic bravado. In the highly competitive tea trade, when fees are not paid, validation not tendered, and subsequent revenue not increased (“value-added” hypotheses don’t always execute), organic practices continue only within the domain of those growers who are committed to organic agricultural doctrine.
Organic tea production is superior for the land, excellent for the grower and processor, and good for the consumer. In the realm of fine tea there are many examples from excellent certified organic production and other superb examples from sourcings that use traditional, centuries-old methodology. A bit of inquisitiveness directed toward your tea supplier should invite discussion about methods used and sourcing of the tea you want to try.
REGULATORY ORGANIZATIONS
The five most visible and highly reputable major regulatory organizations whose logos you will encounter in the marketplace have set standards for organic production (three of these are government agencies and two are private): Regulation No. 2092/91 of the European Union, the National Organic Program (NOP) of the United States, the Japanese Agriculture Standard (JAS), the Soil Association of England, and Demeter-International e. V. of Germany.
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