Additives and Herbal Teas
or "If it ain't broke don't fix it"
A Letter to a Kombucha Tea Grower
By Norbert Hoffmann
Hi Ari,
you asked my opinion about adding acidophilus bacteria or other additives to Kombucha Tea. First of all, there are no long-term studies of the
effects of additives or use of substrates other than black or green tea on K.T. and, furthermore, we don't have any easy comprehensive test instruments available that would tell us that we have a good healthy culture.
Measuring pH and ketones plus our observations - does it look, taste and smell OK, did I get sick from it the next morning - is about all the average K.T. user can do. We don't even know for sure which the essential
components are. Many say that glucuronic acid is the most important factor while others believe that acetic acid plays a role also. We know of a number of other components but we are not sure exactly what they contribute to
the effectiveness of K.T. It is quite possible that several of the factors have to be present at the same time to make K.T. the beneficial remedy it is - similar to the way many medicinal plants work.
Since we are lacking long-term studies and tests, it is my strong opinion that we should always have an ongoing culture using the standard
recipe and that any experimentation should be done parallel to that. Since we don't know what adding new bacteria like acidophilus, substituting or supplementing black or green tea with other teas having high amounts of
essential oils or using flavoring agents like ginger will do to the culture long-term, we can only go by what we know about microorganisms and their behavior.
Whenever several different populations of microorganisms co-exist, you often have survival of the fittest or survival of the ones that get
along the best. Many times there is a rather delicate balance between the different organisms and the environment. Change any of the factors and the individual populations of the various organisms may be affected -
temporarily or permanently.
To give an example: There are approximately twice as many microorganisms in and on our body than there are body cells. Usually they live
together happily and harmoniously without causing any harm. Some of them are opportunistic microorganisms that may be dangerous if they were given free reign. But the environment including our body defenses and other
microorganisms hold them in check. In our mouth there is a large number of different organisms all the time: various types of streptococcus, lactobacillus, actinomyces, bacteroides, fusobacterium, treponema,
corynebacterium and last not least candida. Pretty scary when you see the list for the first time. But these microorganisms in our mouth usually live there without harming us. But we all know what candida can do when it
goes unchecked. Other bacteria may do damage to the teeth enamel if the environment changes - for example a change in acidity. The situation is very similar in most other places of our body, the intestinal tract, urinary
tract, respiratory systems etc. (Tortora et al)
Sometimes, when certain microorganisms come together damaging or even deadly effects may result. One extreme example is the mycoplasma
fermentans, the smallest bacteria that is capable of existing outside of cells. When this bacteria infects cultured cells along with the HIV virus, the cells have been found to die more readily compared with cells infected
by the virus alone. (Tortora et al) In this case it is a virus and a bacteria working together, in other cases it may be various types of bacteria or yeasts. There have been a lot of discoveries made in the field of
microbiology over the years but much more remains to be learned.
We know that essential oils retard the growth of microorganisms. If we use teas with high content of these oils the population of some of the
microorganisms may actually be reduced. This is probably OK for a while. If we would continue to use these as growth media over a long period of time, the culture might get changed permanently as a result. Perhaps the
bacterium glucuronicum might get extinguished. We don't really know for sure. Adding the acidophilus bacteria may be quite harmless or even beneficial - or it may have a damaging effect. Another factor influencing the
growth of microorganisms are the essential building blocks we provide through the tea in addition to the sugar, the water and its trace elements. Black or green tea is high in certain organic compounds containing nitrogen
and other important elements needed for microorganism growth. Some herbal teas may have considerably less.
Reiss experimented with various substrates. Using black tea resulted in 2.25 grams of gluconic acid per liter (~quart) after 2 weeks of
fermentation, while peppermint tea resulted in only 0.04 grams. (quoted by Frank G.) In other words, the culture with black tea produced 54 times more gluconic acid. Now, note that this is not glucuronic acid but gluconic
acid. Nevertheless, it still shows the effects of an herbal tea with a high content of essential oils on the amount of an organic acid being produced. And from the significantly smaller amount of organic acids produced with
peppermint tea, we can conclude that the microorganisms producing them are severely affected either by the high essential oil content of the tea or by the smaller amount of critical building blocks or both. It is probably
OK to continue using peppermint tea (or other herbal teas for that matter) for a few weeks. Change back to black tea and the organisms probably bounce back. Günther Frank always says that K.T. is pretty robust. But do it
for a longer period of time and some of the strains might get weaker and weaker and eventually die out. As a result you probably no longer have Kombucha Tea.
Originally, Günther was a strong opponent of using teas with high essential oil content. He has since modified his opinion to some extent and
doesn't see it quite as narrowly as he used to as long as herbal teas are added to black or green tea and not substituted (in a personal communication about 1 1/2 years ago). For example, Günther's wife Rosemarie
makes delicious K.T. with lemon balm in summer. I had the opportunity to sample it several times during my visits. But, on the other hand, he and his wife always use the standard mixture for ongoing cultures and any
experimentation or variations are done in parallel like I suggested above.
Well, I hope this lengthy comment helps. Let me know if you have any questions or feedback.
Have a nice day.
Norbert
Sources: