This paper was originally written in 1994. The knowledge and understanding
of Kombucha Tea (KT) have evolved since then and continue to evolve. In
this version of the paper, newly added comments which have not yet been
integrated into the paper are printed *** between
asterisks. *** This update is derived from a review of the "Kombucha
FAQ" (Frequently Asked Questions) on the Internet, and from our own
correspondence with some of the 600 members from 43 countries represented
on the Internet Kombucha mailing list.
Kombucha is an ancient tea of Far Eastern origin with immune-sustaining
and broad remedial effects. Kombucha is the product of fermentation by
a "fungus"--actually a symbiosis of yeasts and bacteria--fed
by a proper mix of tea and sugar.
Modern research has examined a variety of folk recipes for Kombucha, fermentation
procedures, dosages and uses, seeking a more exact understanding of the
tea. The information given here has been extracted primarily from two
sources: Rosina Fasching, who reviews the important work of her uncle,
Dr. Rudolph Sklenar, in Tea Fungus Kombucha, The Natural Remedy and its
Significance in Cases of Cancer and other Metabolic Diseases, and Gunther
Frank, who, in his book Kombucha, Healthy Beverage and Natural Remedy
from the Far East, reviews the work of many researchers, from the 20's
to the present, including Sklenar, and presents his current assessment
We secured these books from the Austrian publisher, but as of the Fall
of 1993, they are now available in the U.S. (See Resources)
*** Frank's book is still seen by many as the best
book and is much more widely available as of this writing. ***
We would outline our current information and judgment as follows: (We
do not consider the following information fixed or final in any way, but,
given the current surge in international interest and attention, we would
expect more complete understanding and therefore more specific instructions
to become available in the future.)
Uses and Benefits
While Kombucha has demonstrated a persistent capacity to produce a wide
range of fundamentally important effects, it is a gentle actor. It cannot,
therefore, be expected to overcome effects of continued bad diet and
Recipe and Instructions
The kinds of tea, the kinds of sugar, the balance of tea and sugar, the
length of time allowed for fermentation, and the temperature all affect
the balance of properties and hence the optimum uses of the tea.
For reasons of their serious negative effects in the human system, nutritionists
increasingly recommend against the use of black and green teas and of
refined sugar in any diet. However, all research with Kombucha indicates
that the refined sugar and tea, specifically with high purine (including
caffeine) content, provide the nutrients and the milieu required by the
"fungus" for its most beneficial action. Through a complex sequence
of interacting processes, this action, when executed with optimum tea
to sugar balance, and proper temperature and duration of fermentation,
consumes and/or transforms the sugar (2) and the caffeine.
*** We understand that it is now generally agreed
that caffeine content is not changed by the fermentation. We further understand
that it is quite low, approximately 6 mg. per 4 oz serving (depending
on brewing techniques). A cup of coffee may have about 100 mg. In the
experience of ourselves and others we know who have been markedly sensitive
to caffeine, reaction to KT has ranged narrowly, from none at all to very
Larger batches of Kombucha can be made more efficiently and with better
control. For most people, a one gallon container, which will produce 3-1/4
quarts of tea, is probably the optimum size.
Ingredients you need to make Kombucha in a 1 gallon container: (3)
- One Kombucha "pancake"
- 3-1/4 quarts water (13 cups)
- About 1-1/2 cups finished Kombucha beverage (about 10% of the total
you will be making) (4)
- 307 grams sugar (this amounts to 4 tsp. less than 1-1/2 cups) (5)
- 15.2 grams tea (1 rounded tsp. weighs 3 grams; 1 tea bag weighs 2-1/4
Equipment you need:
- a saucepan (not aluminum)
- a container with as wide an opening as possible (7) (glass, china,
glazed earthenware or plastic--food grade polyethylene or polypropylene;
not PVC or polystyrene)
- a cloth to cover the jar (8)
- a rubber band (9)
- Start the water heating.
- Add the sugar and stir to dissolve. Sugar must be in before water
*** Some instructions now say to boil the water
for ten minutes before adding the sugar. We believe this reflects growing
concern for the purity of our water supply and is not a necessity as
far as the KT is concerned. If you are using chlorinated water, or water
about which you have any question, boiling is doubtless a good idea.
Chlorine could affect the balance of organisms in the culture, and impure
water could introduce unwanted organisms. ***
- When the water boils, turn off the heat, add the tea, and let the
tea steep for 10-15 minutes.
*** Some recipes call for steeping for less time.
This will result in (even) less caffeine; we do not know in what other
ways this may affect the value of the final product. One variation which
aims to produce lower caffeine tea calls for soaking the tea overnight
in cold water in place of steeping in hot water. ***
- Strain off the tea leaves and allow the tea to cool to 98-100 degrees
- Pour the tea into the fermentation container.
- Add 10% Kombucha beverage from a previous fermentation.
- With clean hands, lay the Kombucha culture on top.
- Cover the container quickly and secure it with a rubber band.
- Place the container in a location where it will be warm, (10) can
receive fresh air, and can remain undisturbed. Keep it away from dust,
mold, and mildew. Light is not necessary, and bright sunlight damages
*** Tobacco smoke is potentially lethal for the
culture. Fat droplets released into the air from cooking are also detrimental.
- Depending on the temperature, the ratio of jar opening to volume,
and desired result, allow 8 to 14 days. (11)
- Remove the Kombucha, again with clean hands.
- Pour off the Kombucha into bottles. (12)
- You may leave the yeast sediment in the bottom, which will speed
the next batch. (The fermentation container should be cleaned with hot
water every four weeks or so.)
- Leave 10% of the liquid in the jar (or if you are washing out the
jar, save it and pour it back in afterwards).
- Wash the Kombucha culture carefully under cold running water. Parts
of the culture that seem to be turning brown should be removed and discarded.
- Your Kombucha pancake will continue to grow and multiply.
- New growth is on top, old on the bottom. Remove parts from the bottom
as they become old and brown.
- You'll have excess culture that you can give to your friends. It
can be divided by cutting sections (with sharp scissors) or by removing
Any piece of Kombucha that you don't mean to discard should be kept
submerged in Kombucha beverage.
- If covered with tea and kept in a cool place, the Kombucha culture
will keep for long periods of time.
How much to use and
Recommended maintenance dosage for a healthy person is about 1 1/2 cups,
preferably taken 1/2 cup at a time, three times a day. Because the effects
are different when taken before and after meals, preferred times are in
the morning on an empty stomach, 10-15 minutes before breakfast; before
or after the midday meal, and in the evening sometime before going to
bed. For a person with cancer, Dr. Sklenar recommends 3 cups a day (24
ounces), up to a quart.
*** Many recipes are now cautioning people to start
with only 1/2 cup per day for the first week, and then to increase to
1 cup for another week before going to the 1 1/2 cup amount. ***
(1) See Resources
(2) Using currently available information, the best estimate we can make
of the caloric content and makeup of Kombucha is as follows. In well made
Kombucha, the 100 grams of sucrose (refined white sugar) per liter are
used and hence transformed, by the yeasts and bacteria, into the beneficial
metabolic products--gluconic acid and acetic acid--and perhaps 30 grams
of fructose, a form of sugar which puts less stress on the metabolic regulatory
system. The recommended daily maintenance dosage (11 oz.)
can be expected to supply about 40 calories, or about as many as in half
(3) Besides the fact that one gallon batches are much more efficient to
make and more consistent in their performance than smaller ones, the longer
storage that is likely to result is actually advantageous. Kombucha stored
at a cool temperature actually improves with age, especially if stored
in smaller containers so that the length of time any container is open
during use is shortened. Refrigeration is not necessary either during
storage or use.
*** We have never refrigerated our stored KT, and
have never had any problems, though we have kept it for many months. Nevertheless,
we should note that many recipes now urge refrigerated storage. ***
(4) The addition of finished Kombucha improves the environment in which
the new process begins, by acidifying it.
(5) For the recipe which we are recommending, what we have been able to
learn from the literature and from our own trials would indicate that
less sugar may not sustain the process to maximum utilization of all the
ingredients. On the other hand, it would seem that use of more sugar increases
the likelihood that the process will end with more sugar remaining unused.
(6) This is at the rate of 5 grams tea per liter. It has been our experience
that this amount of tea, in combination with 100 grams sugar, makes a
drink with the most "activity." Everything we read indicates
there are only two kinds of tea that work well, and they must not be compromised:
green (e.g., organic Bancha), or black (organic Oolong preferred).
*** According to the Internet FAQ, black or green
tea are recommended, but are not the only teas which will work. Black
tea, of course, will give you more caffeine. ***
At this time, only Kombucha made with black tea has been tested for glucuronic
acid content. When serious ailments are being treated, such as cancer,
some would advise sticking with the black tea until the efficacy of the
green tea can be tested.
*** We now understand that KT has no glucuronic
acid content. The green tea, known for its native efficacy with regard
to cancer seems the clear choice for the cancer patient. ***
(7) The ratio of air exposure to volume of liquid is important--the larger
the opening the better!
(8) Panty hose or cheese cloth with tight enough weave to prevent entry
of omnipresent and persistent fruit flies, open enough to permit free
entry of oxygen.
(9) Without tight closure with a rubber band, the fruit flies will get
in. Leaving the jar open for more than seconds risks fruit fly entry,
the laying of eggs and subsequent arrival of larvae on the pancake. Any
eggs or larvae must be removed by picking them off and washing.
(10) The temperature should not fall below 64 nor rise above 86 degrees
F. For balanced growth of the yeasts and the bacteria, we have settled
on 77 F. as an optimum. An even temperature is preferable. The fermentation
will proceed more quickly at higher temperatures.
(11) For maximum conversion of sugar and caffeine and hence to maximize
the variety of benefits, we have settled on a ten day period at 77 F.
This produces a Kombucha that is clearly acid (pH 3) but not vinegary.
(12) Use a sieve if desired. The white stringy material is not harmful,
but pieces which have turned brown are best removed.
Warren Stetzel and Chris Joyner
54118 Crum Road
Beallsville, Ohio 43716
February 14, 1994
Revised May 13, 1998
-- RESOURCES --
Frank's book is available from the US distributor:
PRO NATURA Inc.
6211-A W. Howard Street
Niles, IL 60714, USA
Phone (800) 555-7580
Fax (800) 588-0918
Distributor in the USA.
Both retail and wholesale
The Kombucha Journal: <http://www.kombu.de/english.htm>
Kombucha FAQ: <http://w3.trib.com/~kombu/FAQ/index.shtml>
Kombucha mailing list: <http://w3.trib.com/~kombu/FAQ/mailist.html>