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Kombucha: A Tea Guy’s Perspective
Several times in the last couple of years, people have come in to the tea bar and asked if we have kombucha. The first time, I did a quick Google search, looked at the process required to brew it, and said no. After the third time, I figured I should look a bit deeper into this phenomenon. Conveniently enough, the Healthy Beverage Expo was held in Las Vegas alongside the World Tea Expo (the largest trade conference in the tea business) , so I was able to sign up for a kombucha seminar to go along with all of the tea seminars I was taking.
I learned quite a bit in the seminar, although virtually none of what the instructor covered was applicable to a tea shop serving freshly-brewed drinks. Almost everything she talked about applied to RTD (ready-to-drink) bottled beverages, which really doesn’t interest me. We don’t serve bottled tea or soda — or even bottled water — so RTDs didn’t really interest me much. I was there to learn about fresh beverages.
Following the seminar, I did some further research and made an informed decision about selling kombucha in my tea shop. Here is my thought process:
What is kombucha?
Kombucha is a fermented drink made from a fairly heavily sweetened black tea (about 1 cup of sugar per gallon of tea), although other types of tea can be used as well. A symbiotic culture of bacteria and yeast known by the acronym “SCOBY” is placed on top of the tea blend. It grows into a gelatinous mass on top of the tea as it ferments the sugars in the tea mixture. After a week or so, the freshly grown bacteria/yeast mat can be separated out into a new SCOBY for the next batch, and the liquid can be drawn off to drink.
It’s really good for you, right?
First of all, I don’t select teas based on health claims. I select teas that taste good. At times, those goals align, but I’m frankly underwhelmed at the amount of hard data backing most herbal health claims, and I’m not going to pass on health claims to my customers unless they are backed up by honest-to-goodness, peer-reviewed, reproducible studies — preferably with double-blind clinical studies.
Sitting in the kombucha seminar, I was struck by the PowerPoint slide titled “Health Benefits.” It listed every imaginable ailment from cancer to Alzheimer’s, heart disease to diabetes. The list was absolutely stunning. Before I had a chance to react, someone else in the audience asked what the basis was for this list. The instructor informed us that she had recorded everything her friends, family, and customers had told her. If someone told her they drank kombucha and their gout got better, she’d put gout on the list.
In other words, all of these health benefits were unconfirmed hearsay with no scientific basis whatsoever. A short amount of digging brought me to an article on kombucha by the American Cancer Society. I think one quote from that article sums it up really well:
Available scientific evidence does not support claims that Kombucha tea promotes good health, prevents any ailments, or is works to treat cancer or any other disease. Serious side effects and occasional deaths have been linked with drinking Kombucha tea.
Not exactly a ringing endorsement.
Logistics of kombucha
In a tea bar environment, I have dried leaves with a shelf life measured in months. The few fresh items I need, such as milk, boba pearls, and lemon slices, can either be purchased on a moment’s notice at the grocery store, or made in a matter of minutes. Kombucha requires at least a week to brew, which means if you want to serve it fresh, you need to be very good at predicting demand a week in advance.
If you wish to store and keep it, you have to bottle or keg it, and that takes me back to the RTD issue I opened this article with. If I’m going to serve a bottled beverage, I’d might as well buy it from someone else instead of trying to ferment it myself.
Fermentation leads to another issue as well. The yeast in the SCOBY does exactly what yeast does in beer or wine: it consumes sugars and excretes alcohol and carbon dioxide (CO2). The CO2 provides carbonation, most of which is allowed to escape. The alcohol is another issue. The Federal government puts strict controls over alcohol content in beverages. If you wish to sell fresh-brewed kombucha, you must carefully control and measure the amount of alcohol.
Not only can we not sell beverages to children if they contain more than a fraction of a percent alcohol, but without the proper licenses, we can’t produce alcoholic beverages in the tea bar anyway.
My conclusion
I used to do a lot of homebrewing. I really enjoyed making and drinking my own beer. If I still had all of my equipment set up for the beer, I’d probably brew up a batch of kombucha just for fun. I’m not, however, going to make it in the tea bar because the logistics are complex, it doesn’t fit the business model of freshly-brewed tea, and the health benefits are unsubstantiated.
Teas, Tisanes, and Terminology
Foliage of a Camellia sinensis bush — the plant that “real” tea is made from.
Language evolves. I get that. Sometimes changes make communication easier, clearer, or shorter. Sometimes, however, the evolution of the meaning of a word does exactly the opposite. The subject of this blog is a good example.
The word “tea” refers to the tea plant (Camellia sinensis), the dried leaves of that plant, or the drink that is made by infusing those leaves in water.
The word “tisane” refers to any drink made by infusing leaves in water. Synonyms include “herbal tea” and “herbal infusion.”
Technically speaking, all teas are tisanes, but most tisanes are not teas.
In today’s culture, however, practically anything (except coffee and cocoa) that’s made by putting plant matter in water is called a tea. What’s my problem with that? It makes communication more difficult, less clear, and less terse.
- There is no other single word that means “a drink made with Camellia sinensis.” If we call everything tea, then we have to say “real tea” or “tea from the tea plant” or “Camellia sinensis tea” or something similarly ludicrous every time we want to refer specifically to tea rather than to all tisanes.
- There is a perfectly good word for “leaves infused in water.” There is no need to throw away “tisane” (or “herbal tea” or “infusion”) and replace it with a word that already has another meaning.
“But Gary,” I hear you cry, “people have been calling herbal infusions ‘tea’ for a long time!”
That’s true. I sometimes slip and call rooibos a tea myself. “Herbal infusion” is even an alternate definition of tea in the OED. I still maintain, however, that it makes clear, precise communication more difficult when trying to differentiate between tea (made from the Camellia sinensis plant) and drinks made from chamomile, honeybush, and willow bark.
Rooibos
Other words that go through this process are forced through it. Rooibos, for example, is the name for a specific tisane and the plant it’s made from (Aspalathus linearis). The word is Afrikaans for Red Bush. Despite the longtime use of the term in South Africa (the only place the rooibos plant grows), it was almost unknown in the United States in 1994 when Burke International of Texas registered “rooibos” as a trademark. This meant that in the United States, only Burke and its subsidiaries could use the common name of the plant. Had Burke not surrendered the trademark after starting to lose lawsuits, people would have been forced to come up with a new word.
Unfortunately, that wasn’t a decisive victory, as the South African Rooibos Council is being forced to repeat the process now with a French company.
As more people in the U.S. discover green rooibos, the name “red bush” becomes more confusing anyway. Rooibos, in my humble opinion, should remain the generic term here.
Oxidation vs. fermentation
There are other words in the tea industry that suffer from ambiguity and questionable correctness. You will find quite a bit of tea literature that refers to the oxidation of tea as “fermentation.” I had a bit of a row with Chris Kilham — The Medicine Hunter on Fox News — about this subject (it starts with “Coffee vs. Tea: Do your homework, Fox News” and continues with “Chris Kilham Responds“).
Fermentation and oxidation are closely related processes. That’s certainly true. But oxidation is the aerobic process that is used in the production of black and oolong tea, and fermentation is the anaerobic process that’s used in the production of pu-erh tea. Using the word “fermentation” to describe the processing of black tea may fit with a lot of (non-chemist) tea industry writers, but it makes it difficult to explain what real fermented tea is.
Precision matters
In chatting with friends, imprecise use of words doesn’t matter. If someone asks what kind of tea you want and you respond, “chamomile,” it’s perfectly clear what you want. But you’re an industry reporter, medical writer, or marketing copywriter, your job is to communicate unambiguously to your readers. Using the most correct terminology in the right way is a great way to do that.
Book Review: 20,000 Secrets of Tea
I read a lot about tea (what a surprise, eh?), and try to carry a decent selection of tea books in my bookstore. When somebody recommended the book 20,000 Secrets of Tea: The Most Effective Ways to Benefit from Nature’s Healing Herbs by Victoria Zak, I decided to give it a look. I confess I was put off by the subtitle, because it sounds more like a book of herbal medicine than a book about tea. Then I flipped the book over and took a look at the back cover. There I saw this:
“An Ancient Chinese Legend: Once there was a man who knew 100,000 healing properties of herbs. He taught his son 80,000 secrets. On his deathbed, he told his son to visit his grave in five years, and there he would find the other 20,000 secrets. When the son went to his father’s grave, he found, growing on the site, the tea shrub…”
Okay, that’s more promising. Especially this line in the next paragraph: “A simple cup of tea not only has the power to soothe and relax but to deliver healing herbal agents to the bloodstream more quickly than capsules, tinctures, or infusions.” That line indicates that they know the difference between tea and infusions/tisanes, and that this book is going to be about tea.
Oh, my, was I wrong.
Page one starts out with a description of the legend of the origin of tea. Chapter one continues on, repeating the story from the back cover and then providing some of the history of tea as a drink. Within five pages, it has transitioned to herbal infusions, and that’s pretty much the end of discussion of the tea plant (Camellia sinensis).
I flipped through the next 220 pages looking for more information about tea (after all, the next 20,000 secrets are all about the tea shrub, right?) and I all found was descriptions of various herbs along with multitudinous health claims about each (more on that in a moment).
I went to the index looking for tea. The index is 15 pages long, normally a good sign in a reference book. Under “tea” I found reference to pages 1-4, mentioned above. Under Camellia sinensis, nothing. Flipping through the alphabetical collection of herbs, tea isn’t even listed. I checked under “black tea” and found a two-page spread in the middle titled “Green, Oolong, Black: the legendary teas.”
Zak begins by repeating the origin legend from page 1, and then proceeds to talk about fermentation (none of those teas are fermented, although black and oolong are oxidized) and rates the three styles in order of “medicinal strength: (green, then oolong, then black). Nowhere does she mention white or pu-erh tea, and nowhere does she define what “medicinal strength” actually means. Obviously, when there’s so little information, it leads to gross overgeneralization. When you use up that little bit of space with statements like “Green tea’s polyphenols are powerful antioxidants are reputed to be two hundred times stronger than vitamin E. It has anticancer catekins (sic), which protect the cells from carcinogens, toxins, free radical damage, and help to keep radioactive strontium 90 out of the bones,” there’s no room left to describe the differences between tea styles, how to properly steep a cup, or any of the other subjects that I expected this whole book to be about.
Incidentally, none of those rather incredible health claims are footnoted, no studies are cited, and no backup data is provided.
All in all, this book is tailor-made for herbalists — especially those that don’t worry much about the scientific basis of their health claims — but pretty well useless for tea enthusiasts.
A Tea Tasting and Class
This article first appeared in the May 2010 issue of the Local Rag newspaper, describing a tea tasting and class I held at our bookstore before we added the tea bar.
When I was a kid, tea was something that came in bags with a little tag that said “Lipton.” Visits to a Chinese or Japanese restaurant introduced me to the “other” kind of tea: green tea. The first time I ordered tea in a nice restaurant, I encountered the fancy presentation box, containing exotic varieties of tea like chamomile, Earl Grey, English breakfast tea, and Constant Comment. In high school, I drove a delivery truck for an office supply store in Boulder, Colorado, and one of my stops was Celestial Seasonings.
By that time, I was probably a typical American tea consumer. I classified teas into herbal, green, medicinal, and “ordinary.” Not until quite some time later did I discover just how much I was missing, and in an April tea tasting at Red Lodge Books, I tried to pass on a bit of what I’ve learned. This article is a distillation of the talk I gave that day.
All “true” tea comes from the same plant: Camellia sinensis. There are three major variants. The China bush (var. sinensis), the Assam bush (var. assamica) from India, and the Java bush (var. cambodi). Within those broad categories are over 1,000 individual subvarieties. Just as red climbing roses and yellow tree roses are both roses, all of these subvarieties are still Camellia sinensis, the tea plant.
There are six generally-accepted ways to process Camellia sinensis leaves, which produce white, yellow, green, oolong, black, and pu-erh. Yellow tea is so rare that I decided not to cover it. All “true” teas have caffeine, including the delicate whites and greens. Red tea (a.k.a. African rooibos), which I’ll discuss next month, is made from a different plant that does not have caffeine.
White Tea
White tea is the least-processed, and generally lightest and sweetest-flavored tea. It is typically more expensive than black or green teas, and is recognized as having significant health benefits. It is brewed at a lower temperature, and steeped for a short time. The leaves can be re-used, to make 2-3 cups of tea from one teabag or container.
The white tea we tasted at the bookstore was Rishi’s organic Silver Needle (Bai Hao Yin Zhen), from the Fujian province of China. This tea was voted the best tea in the world at the 2008 World Tea Championships, and the best white tea in 2009. The taste is very light and subtle, and there is a wonderful jasmine-infused version available as well.
White teas start out as young budsets (an early bud with or two leaves). After picking, they are “wilted” indoors to get some of the moisture out, and then baked or panned. After a light rolling of the leaves, they are dried and packaged for shipment.
Green Tea
Green tea is the traditional tea of China and Japan. It has long been lauded for its healthiness, and intricate ceremonies have been developed around its preparation. People study the Japanese Tea Ceremony for years before performing it publicly. Like white tea, it is brewed at lower temperatures, and can yield 2-3 infusions.
The green tea we tasted was an organic Sencha from the Kagoshima Prefecture of Japan; voted the best green tea in the 2008 championships. It is a very traditional green tea, grown in volcanic soil, yielding a deep almost grassy flavor.
After picking, the leaves are steamed or panned, rolled, and then dried. Sometimes, they’ll be formed into balls or other shapes before drying.
Oolong Tea
Oolong is a very highly-processed tea; one of the most complex to produce. It is generally flavorful and rich without the bitterness often associated with black teas. Unlike green and white teas, the leaves are partially oxidized, which darkens the color and intensifies the flavor.
We tasted an organic Wuyi Oolong. The Wuyi Mountains in Northern Fujian are where oolong tea was first produced, and this variety has a roasted aroma, complex flavor, and sweet finish.
To make oolong tea, the freshly-picked leaves are first wilted (partially dried) in the sun, and then again indoors. They are tossed in a basket to bruise them, and then partially oxidized (typically anywhere from 30-70%). After oxidation, the leaves are baked or panned, and then rolled. The final steps are drying and firing, which produces the smoky aroma.
Black Tea
By far the most common type of tea in Europe and India, black tea is usually brewed hot and strong. Many cultures serve it with milk, sugar, or both to mitigate its inherent bitterness, and it is often flavored with lemon, orange, or other spices (Red Lodge Books has a fascinating vanilla black tea). Black tea flavored with bergamot is known as “Earl Grey.” Black teas are also the basis of English and Irish breakfast tea. Unlike white, green, and oolong teas, black teas are generally only infused once: use the leaves and discard them.
At the tasting, we had Rishi’s organic fair-trade China Breakfast, which won “best breakfast blend” at the 2009 World Tea Championships. It’s rich, malty, and robust; great for the first cup of the morning.
Black teas are usually made with an indoor wilting, followed by a cutting or crushing step. This can range from a light crush to a full “CTC” (crush-tear-curl). This exposes more of the leaf’s insides to assist in oxidation. Black teas are 100% oxidized, yielding higher caffeine content and stronger flavor. Following oxidation, leaves are rolled and dried.
Pu-Erh
This is probably the least familiar process to Americans, but it has been around in China for centuries. What differentiates it from black or oolong tea is a fermentation step at the end of processing. Although the term “fermented” is often incorrectly used instead of “oxidizing” for black teas, pu-erh is the only variety that is actually fermented.
A cake of 2009 Tong Qing Tang Pu-erh tea.
If you’ve ever had a mulch pile, you’re familiar with the process: plant matter is piled up wet, and left alone. The inside of the pile grows hotter as it ferments. Unlike most teas, which are served as fresh as possible, pu-erh is often compressed into cakes (sometimes immense bricks) that can be stored for years. Century-old pu-erh cakes are sold at auctions for thousands of dollars.
Pu-erh is brewed in boiling hot water, and can be re-infused at least 6-8 times. I’ve used leaves ten times and still gotten good flavor from the tenth infusion.
At the tasting, we had a classic loose-leaf organic fair-trade pu-erh from Yunnan, China. The flavor was earthy and rich. The description may seem off-putting to some, but it’s definitely worth trying a good pu-erh.
Chris Kilham responds
Chris Kilham (left) and Dr. Manny from Fox News
A few days ago, I posted an admittedly rather snarky article on this blog entitled “Coffee vs. Tea: Do your homework, Fox News.” The main subject of the article was Chris Kilham, the “Medicine Hunter” from Fox News. Chris has responded to the article in email, expressing an interest in carrying on a dialog. Here is what he sent me (verbatim, and in its entirety):
Hi Gary- I saw your mistaken response to my segment on FOX, and thought I’d take time out to reply. Having studied coffee and tea deeply for decades, and having read thousands of pages of science on both, I stand by the claim that coffee is more potently antioxidant ounce per ounce. More Americans do drink black tea rather than green, the fermenting of tea does degrade the antioxidants, and no, the benefits of coffee are not limited to caffeine. I referred to the work of Astrid Nellig, who compiled over 300 human studies on coffee, not the others you noted. And yes, oxidation is in fact “rusting.” The exact same process occurs to cells that occurs to metal, though metal is not living tissue. I see you leave no place on your blog for intelligent feedback. Good idea. Before you rant off on a tangent, you really should get your science together. I have. Point by point I will be happy to go toe to toe. Enjoy.
First, Chris, I hope it was okay to use the thumbnail picture from your Medicine Hunter website. If you would prefer that I didn’t have it on my blog, let me know and I’ll remove it post haste.
Thank you for responding to my post. I appreciate getting feedback direct from the source, and I know you’re busy. Before going through your email point by point, I’d like to start by addressing the very last issue you raise: that there’s “no place on [my] blog for intelligent feedback.” As I said, I actively encourage intelligent feedback. There’s a place on every single blog post for people to leave their comments. If you’re looking at the front page of the site, it’s a link at the end of the post. If you’re looking at an individual article, it’s a section at the end with two tabs: one to see existing comments and one to leave your own. Please feel free to leave your comments on this or any other post on my blog, whether you agree with me or not.
Now, let’s — as you said — go point-by-point, toe-to-toe. I will quote your email, and then respond.
“Having studied coffee and tea deeply for decades, and having read thousands of pages of science on both, I stand by the claim that coffee is more potently antioxidant ounce per ounce.”
I did not dispute this. I said that I was unable to find meaningful studies regarding flavonoid content that covered multiple types of tea and coffee and various ways of preparing them, so I have no way of disproving your claim. What I did say is, “Flavonols aren’t the only basis for measuring the healthiness of a drink.” I will expand that to say that antioxidants in general aren’t the only things that make a drink healthy.
But if you can show me a study comparing antioxidants in coffee with antioxidants in black, green, white, oolong, purple, and pu-erh tea, I would love to see it. Really. I get that question a lot and I don’t have an answer for it.
“More Americans do drink black tea rather than green…”
I agree with you. In fact, I said “One accuracy point for Kilham” after I verified the claim with FAO’s statistics.
“…the fermenting of tea does degrade the antioxidants…”
Black tea is not fermented. This little piece of misinformation is a pet peeve of mine, and it’s one of the things that prompted me to write the original article. Black tea is oxidized. Fermentation is an anaerobic process. There are fermented teas (a favorite style of mine called shu pu-erh is both oxidized and fermented), but they represent such a miniscule percentage of the tea consumed in the United States that they don’t factor into this discussion. I will continue the discussion assuming you meant to say “oxidized” rather than “fermented.”
I am neither a chemist nor a nutritionist, so you’re going to have to tell me what “degrade” means in this context. You had originally said that they were “lost,” and I responded that “Flavonols aren’t ‘lost’ during oxidation; most (but not all) are converted into different antioxidants called theaflavins, and some convert to thearubigins (which produce the reddish hue of black tea).” Am I wrong?
“…and no, the benefits of coffee are not limited to caffeine.”
Did I say they are? No. I said, “But yes, coffee does contain antioxidants. So, in fact, does tea.” My reference to caffeine was specifically related to your claim that coffee can improve a bad mood. Every study that I found showed that you are absolutely correct. Coffee can improve a bad mood because of the caffeine, which means that tea and Mountain Dew can improve bad moods as well.
“I referred to the work of Astrid Nellig, who compiled over 300 human studies on coffee, not the others you noted.”
I am unfamiliar with Nellig’s work, but if the studies are specifically on coffee, they wouldn’t have pinged my radar (I am uninterested in coffee). If any of Nellig’s studies compare coffee with various types of tea, I’d like to read them, though.
“And yes, oxidation is in fact ‘rusting.'”
This could be an interesting discussion. When I was taking chemistry in school, I would have been smacked for saying that, for example, copper had rusted. Oxidizing was presented as the more general term. All rusting is oxidation, but not all oxidation is rusting. Perusing Merriam-Webster’s dictionary, however, I see that one of the definitions of rust as a verb is “to form rust: to oxidize.” And since the primary definition of oxidize is “to combine with oxygen,” I suppose the first part of your statement is true, based on current dictionary definitions. But do you really want to use “rust” as a synonym for “oxidize” in discussing living organisms? Try this:
Substituting “rust” for “oxidize,” a simplified description of the cardiovascular system would say that you inhale air into your lungs, where oxygen in the air is used to rust your red blood cells. Your arteries and capillaries carry those rusted blood cells to the rest of your body, where the red blood cells “un-rust” as they cause other cells in your body to rust. The de-rusted blood cells then return, via veins, to be rusted once again in the lungs.
Accurate, using those current Merriam-Webster definitions, but it sure sounds strange.
“The exact same process occurs to cells that occurs to metal, though metal is not living tissue.”
Really? To the best of my knowledge, metal is unable to use up oxygen and become un-rusted. Living cells can. It’s not the same process.
The “oxidation vs. rusting” discussion is largely semantic, though, and I don’t want this to turn into a massive debate about free radicals and properties of antioxidants. That wasn’t the point. The point was that your “Q&A With Dr. Manny” article went on a great length about health benefits of coffee without acknowledging that many (all?) of those benefits are shared with various types of tea. The only health benefits of tea that you brought up were antioxidants, and that’s only a single piece of the puzzle.
“Before you rant off on a tangent, you really should get your science together. I have.”
Okay, if you want to call my post a “rant,” I’ll have to agree. It was. But it was by no means “off on a tangent.” It directly addressed your Fox News story, directly on-point. It wasn’t off-topic. And I haven’t seen you call out one single scientific error in what I said (unless you want to call my bullheaded prescriptivism on the definition of “rust” a scientific error).
I am a 
Tea With Gary 