Many Rivers Books & Tea weblog

On Saturday November 22 Stuart and I conducted our monthly Many Rivers tea tasting on the topic of “Tea for Digestion.” We had a great crowd, an excellent discussion of a lot of research on the topic, and we tasted what may have been the most diverse flight of teas we’ve ever done in over five years of conducting tea tastings. Here is the list:

• White: Silver Needle
• Green: Emerald Sencha & Kukicha
• Oolong: Cold Summit Tung Ting
• Pu-erh: Silver Needle Beencha & Imperial Pu-erh
• Herbal: Tulsi Ginger

Several interesting principles emerged from the research that we did in preparation for this tasting. Following is an outline of the subjects discussed, which can be summarized in two points:

• Camellia sinenis (tea) is recognized both at a general level as an aid to the digestive processes of the body
• Specific types of tea have been recognized as having special properties that support and enhance digestion

Although we didn’t structure the actual discussion this way, in preparing for the event I had organized the research on tea and digestion into three more or less distinct perspectives, followed by an outline of the topics covered in the discussion on each perspective:

•  Traditional Chinese Medicine (TCM)
• Alternative Western Medicine
• Western Scientific Studies

  Traditional Chinese Medicine
  In TCM, food and drink are understood to be medicinal in nature. Proper digestion is key because the body has to be able to absorb the beneficial substances that we ingest. As a widely appreciated remedy in the context of TCM, tea is understood to have the following properties:

  • Tea helps to regulate & promote healthy movement of qi (chi), i.e., life-force energies
  • Tea helps with the digestion of fatty foods 
  • Tea is often taken immediately after meals as a digestive aid
  • Pu-erh tea invigorates the Spleen, disinhibits dampness, reduces stomach heat, moves stomach qi downwards, counteracts & flushes alcohol toxins – in fact, pu-erh is widely used as a remedy after drinking too much alcohol

    Alternative/Holistic Western medicine
    In alternative Western medicine, our research identified three principal assertions related to tea and digestion: Acid/Alkaline balance of body tissues; Diuretic properties of tea; “Adaptogens” in tea. Here are the summarized points:
     

    Alkalinity/Acidity
    • Tea assists digestion by neutralizing excess acidity and preventing fermentation and putrefaction in the stomach; moreover, more acid body tissues are less healthy than more alkaline tissues, so ingesting more alkaline substances is beneficial for the body. Example: Alkalization of mouth, throat and stomach reduces halitosis
    • Tea leaves freshly picked are maximally alkaline. Processing increases acidity, so whites are more alkaline than greens, greens are more alkaline than oolongs, and black teas may well be acidic rather than alkaline.The acidity/alkalinity of tea may be due in large part to the pH of the water used to brew the tea – ideal water for tea should be slightly alkaline
    • Overbrewing tea, whether from too long an infusion, or using water that exceeds the ideal temperature for the kind of leaf (esp. green teas), can make the brew more acid because more tannic compounds are incorporated in overbrewed teas
    • Since blood and tissue acidity promotes calcium loss from bones & teeth, daily consumption of alkaline teas reduces osteoporosisTea is a diuretic that flushes toxins from the body antioxidant and alkaline properties of tea remove toxins from tissues that are then excreted

    Tea contains “Blood Adaptogens”

    • Adaptogens are medicinal compounds alleged to regulate blood pressure, balance blood sugar, and prevent thickening of the blood
      

    Scientific Studies
    Results of new scientific studies of the benefits of tea for the body are regularly reported in the scientific and popular media. Many of these studies are relevant to the subject of tea and digestion. As Stuart pointed out at the tasting, it is important to recognize that the nature of scientific inquiry and investigation means that studies are generally constructed to answer more narrow questions than those addressed in TCM and alternative, holistically-oriented western medicine. None is “better” than the others; each approach simply has its own different strengths.

    Here are some points that emerge from a cursory look at currently available studies on tea and digestion:
     

    • Thermogenic (heat-producing) effects of tea on the body:
    • Higher metabolism rate produced by regular tea drinking (which is the basis of claims for tea promoting weight loss)
    • Higher metabolism of fats in particular produced by drinking tea
    • One of the most important antioxidant compounds in tea, EGCG (Epigallocatechin gallate) also has an anti-inflammatory effect within the gastrointestinal tract
    • EGCG blocks absorption of cholesterol by the body, in addition to the action of tea in removal of cholesterol & sticky plaques from walls of blood ; plus it promotes excretion of cholesterol-containing compounds
    • Black tea has been demonstrated to have anti-ulcerative effects in animal studies
    • Black teas have been shown in animal studies to assist in regulation of serum blood sugar levels; although as yet unproven in humans, black tea consumption may thus help prevent diabetes

    This is just the briefest of outlines of material on the benefits of tea for digestion. We welcome comments on and questions about this posting. Please join the ongoing discussion!

Posted by Rob Schmidt at 07:19 PM | Permalink | Comments (3728) | TrackBacks (0)

There comes a time whenever we do tea tastings at Many Rivers, usually after the third of fourth cup of tea, when the mood discernably shifts. Everyone seems to relax and pool their energy. We go from being a collection of individual tasters to being a coherent group of adventurers sharing a common experience. About that time, I usually joke that the L-theanine has just kicked in.

L-theanine is a major amino acid primarily found in green tea that has been shown to have some interesting psychoactive properties in part because it is able to cross the blood-brain barrier. Animal neurochemistry studies have shown that L-theanine increases brain serotonin, dopamine, and GABA levels. Other studies have shown that L-theanine reduces the body's reaction to mental stress by lowering the heart rate and salivary immunoglobulin A (s-IgA) via a reduction of sympathetic nervous activation. L-theanine has been shown to enhance cognitive abilities, enhance alpha wave production, and improve the body's immune reaction. One recent double blind study (2004) compared the effects of 200mg of L-theanine to 1 mg of alprazolam (Xanax) in reducing anxiety in volunteers. The results showed that L-theanine outperformed alprazolam in showing enhanced relaxing effects for volunteers who were already relatively relaxed, while neither seemed to show much effect for volunteers starting out in an agitated state.

An L-Theanine extract is available through Suntheanine, a Japanese company that holds numerous patents on processes for extracting L-theanine from gyokuro tea leaves. Japanese green teas (e.g. gyokuro, sencha) appear to have the highest concentrations of L-theanine of all common teas. Japanese matcha has by far the greatest concentration of L-theanine of any tea by virtue of the fact that it consists of actual ground tea leaves rather leaves used for infusion. Our own experience of a wide variety of teas, however, is that the relaxing effects of L-theanine can be found in any good cup of tea.

The presence of L-theanine in tea accounts for the vastly different experiences we have of the effects of caffeine when drinking a cup of tea and drinking a cup of coffee. Whereas the oils and alkaloids in coffee tend to promote a stress response in the body that heightens a sense of panic when combined with the effects of caffeine, L-theanine tends to combine with caffeine in tea to produce a calm, relaxed sense of alertness. It is no surprise that tea has long been an ally of Buddhist and Taoist (Daoist) monks in supporting their meditation. In fact the history of the spread of tea and the history of the spread of Buddhism run parallel as monks and traders brought tea and the Dharma along with them on their journeys along the Silk Road.

When you drink your next cup of tea and enjoy that soothing relaxation as the troubles of the world drift away like steam floating over your hot brew, take a moment to appreciate the magic of L-theanine, just one of the many wonderful aspects of this amazing beverage.

Posted by Stuart Goodnick at 10:52 PM | Permalink | Comments (648) | TrackBacks (0)

This Saturday October 25 Stuart and I will conduct our first oolong-only tea-tasting at Many Rivers in quite a while. I’m looking forward to the occasion for many reasons, but principally because oolongs are my favorite class of teas. This personal enthusiasm comes through, I think, in the write-up that I did to advertise the tea-tasting in our October newsletter:

This year’s tea is excellent in its own, quite distinctive way. The difference is most noticeable in the lesser degree of roasting to which these leaves had been subjected compared with the previous year’s tea, which brings more to the foreground the non-roasty flavor elements.

And that’s what I love and appreciate about oolongs. That’s why oolongs inspire such passion. In the western world, the closest comparison to oolong lovers I can think of are with those who seek in the finest red burgundies similar evanescent complexities on the palate. The best oolongs are art on the tongue. Enjoy!

Posted by Rob Schmidt at 01:34 PM | Permalink | Comments (147) | TrackBacks (0)

Posted by Rob Schmidt at 01:26 PM | Permalink | Comments (51) | TrackBacks (0)

This posting describes an unusual tea-tasting event that we held in the store on Saturday September 13, 2008. We wanted to test the proposition that differently sourced waters can produce vastly different palate experiences in the resulting brews. In the tea world, and in extant literature on tea, the crucial importance of the quality of water  has been accepted wisdom at least since the first great tea sage Lu Yu wrote, some 1250 years ago, a treatise on the twenty best sources of water for tea in China. This was a companion volume to his still highly regarded book The Classic of Tea.

Our own experience prior to this tasting event tended to confirm this point. Nevertheless, we wanted to conduct a rigorous contemporary test, and it occurred to us that one of our monthly tea-tasting events would be a great occasion to do so.What we found, as described below, both confirmed this principle but also produced several surprises. Following is the description of that event that we posted on the “Upcoming Events – Special Events” section of our website:

Tea is Mostly Water: How the Qualities of Water Influence Brewing Tea
We know that water from one source tastes better than water from another source. But few of us actually test how using water from differing sources influences how tea leaves brew tea. In this unusual comparative tea tasting, we will brew several teas using waters from distinctly different sources. Given conditions as identical as we can make them (particularly water temperature, brewing vessel and amount of leaf) except for the differing water sources, we may be amazed to discover that not just taste can be affected by which water we're using; even the color and intensity of the tea liquor may be visibly different. Join us for some fun, comparative science in service of the spiritual art of brewing tea that provides health and tastes sublime.

We decided that it would be best to create a blind testing where our customers would serve as unbiased testers. Tasters were provided with a form to record notes. In the actual event, roughly one dozen people participated. While the tasting was blind to everyone but myself (blind to other Many Rivers staff as well), I did tell tasters beforehand which water sources we were using:

1. Distilled bottled water from the supermarket
2. Sebastopol city tap water
3. Alhambra bottled mountain spring water
4. Untreated local well water from a shallow 30 ft well in my backyard, about 100 ft from an artesian spring on a neighbor’s property

We began by tasting the four waters without making tea – but that morning I boiled a quantity of each of the four samples, and allowed them to cool to room temperature, because I wanted the tasters to try the water just as it would be when used to make tea. This had the benefit of removing the chlorine from the city water sample (boiling removes the chlorine gas added to water to kill disease organisms).Tasters were mixed, but there was agreement that the water that was eventually revealed to be distilled water was very drinkable. Several tasters preferred the distilled water over the other three. Preferences were fairly evenly mixed among all four waters.

Then in the order of waters listed above, we first brewed a green tea (Lu Shan Clouds & Mist), then an oolong (Phoenix Mtn. Single Grove Almond Fragrance), and finally a black (Selimhill Estate 2nd Flush Darjeeling) from each of the four water sources. We took great care to use the same amount of leaf in each case, and used the same temperature water, in identical brewing vessels.

The most notable clear-cut reaction of tasters was their “anti-preference” for the distilled water source for all three teas. This pronounced distaste for tea brewed with distilled water strongly supports the view that dissolved mineral content is crucial for producing tasty teas. We expected this result, and our tasters confirmed it.

The biggest surprise of the tasting was that more tasters preferred the green tea brewed in Sebastopol city water to the other two non-distilled choices! (Although there were preferences expressed for each of these other non-distilled water sources.) I did NOT expect that result at all! As I understand it, this water comes from wells deep under the nearby Russian River, so that it consists of river water naturally filtered by 100 ft of sediments. In any event, with chlorine removed, it was the top vote-getter for green tea in our blind tasting.For the oolong and black teas, preferences were more or less evenly distributed among the three non-distilled water sources.So there you have it! I would summarize the noteworthy conclusions to our blind tasting as follows:

1. Water that tastes good to drink may or may not be good for brewing tea
2. Distilled water does NOT work for brewing tea. Tasters reported a flatness of taste for water brewed with this water
3. Surprisingly, Sebastopol city water makes very acceptable tea

Perhaps in 2009 we’ll conduct another tasting comparing a variety of other waters.

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