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Part One - Kombucha FAQ

Frequently Asked Questions

About Containers

© Copyright  1995 -  2000 Colleen M. Allen.







Miscellaneous (part 1 of 2 -  6.1 - 6.50 )

Miscellaneous (part 2 of 2 -  6.51 - 6.96)

Kombucha Colony



Kombucha FAQ Home Page




4.1 What type of container should I use to ferment my Kombucha Tea?

To ferment the tea some people use stone crocks but everybody can't get those. You can also use gallon size glass pickle jars, or glass Sun-Tea jars, or a round glass fish bowl. If you use a gallon jar, do not use the metal lid that may come with it. Some people like to use a container that has more width than height, such as large glass mixing bowls, enamel roasters, crock pots, etc.

Be sure the container you use is large enough to hold at least one gallon of liquid. Remember to allow for space that is taken up when you add your Kombucha colony. Do not fill the container all the way to the brim, leave several inches between the tea solution and the top of the container. Avoid metal, or metal-containing materials. You should stick with stone, glass, or #1 or #2 food-grade plastic, which is suitable for acidic foods. The glaze on some ceramics may contain trace amounts of lead, so unless you are certain that this in not the case, avoid ceramics as well. Acidic beverages will leach the lead out of the glaze. Crystal may contain lead also, so it's not advisable to use any type of crystal container.

4.2 Can I use a plastic container to ferment my Kombucha Tea?

Yes, But if you do use plastic, be very sure that it is a good quality food grade plastic that is recommended for acidic wet foods.

4.3 What do the code numbers on the bottom of plastic containers indicate?

The Society of the Plastics Industry, Inc., has created a coding system for plastic containers. They began phasing it in on July 1, 1988. The code numbers (1-7) inside the three arrows on the bottom of plastic containers are used to distinguish the different type of plastic resins for recycling purposes. Many people use plastic containers to store and ferment their Kombucha Tea without knowing the type of plastic used in their containers or even if they are safe to use for foods. When using plastic containers to store food products, or for fermenting your Kombucha, it is vital that you know about the safety of the plastic container you are using. Not knowing this vital information can turn out to be a dangerous practice. Any plastic containers having a number higher than #2 are not safe to use for fermenting your Kombucha Tea or for storing it. In fact any plastic which has a number higher than #2 should not be used for any type of food storage. The following information will give you a better idea of the types of plastic and their use.

4.4 What type of pot should I use to boil the water for Kombucha Tea?

You can use non-magnetic stainless steel pots, Corning Ware™, Pyrex™, or any other heat-proof glass.

4.5 Can I use an aluminum pot to boil water to make Kombucha Tea?

No. Never use aluminum for any part of this process as tea is acidic by its very nature and will leach aluminum into your tea -- NOT what you want to happen! Even plain water will leach aluminum out of the pot and into the water. Water corrodes aluminum, and the higher the temperature, the greater the corrosion.

4.6 What type of cover should I use to cover my fermenting Kombucha Tea?

Never cover your fermenting tea with a metal or any solid lid. It is best to use a tightly woven cloth, disposable unbleached coffee filters, unbleached paper towels, or similar type covers. Do not use cheesecloth, as it has too loose a weave--this allows dust and vermin (fruit flies, ants etc.,) to enter the fermenting container.

4.7 Why do I need to cover the fermenting Kombucha Tea containers?

You need to cover the fermenting Kombucha Tea with a cloth, or unbleached paper covering, to prevent air-borne dust (which may be laden with mould, bacteria and wild yeast spores) from getting into your fermenting Kombucha. These covers will also allow oxygen to reach the colony, and allow carbon dioxide gas to escape. To stop fruit flies etc., from crawling in under the cover, make sure the edges are held tightly to the container with an elastic or rubber band.

4.8 Can I use pottery, crystal, or painted ceramic containers to store or ferment my Kombucha Tea?

The FDA advises people not to store Kombucha in painted ceramic containers or vessels made of lead crystal, because the ferment is extremely acidic and could cause harmful levels of lead to leach into the fermented tea.

4.9 Can I use Tupperware™ to ferment my Kombucha Tea?

According to Günther Frank, Tupperware is a high-grade synthetic material of the polyolefine group, e.g., polyethylene (PE), or polypropylene. Wine or cider which has a pH value similar to that of Kombucha, is also stored in containers of this food-grade material. However, you should avoid containers made of polyvinyl chloride (PVC), or polystyrene. Sterol is damaging to one's health and can pass from containers made of this material, into the liquid undergoing fermentation.

4.10 Where can I find one gallon glass jars to ferment my Kombucha Tea?

You might try "Subway." They have one gallon glass pickle jars that can be used for the Kombucha Tea. In some cities they give them away to anyone who has a use for them. Some people prefer a wider mouth jar, but you can not beat the price. Also most stores sell gallon "Sun-Tea" jars made of glass that have a built in spigot.

4.11 Where can I find large glass containers to brew Kombucha Tea?

Large glass containers can be purchased through a chemical supply house or sometimes the chemistry stock room of a University. Other possibilities are a glass water-bath or large fishbowls, or glass two-gallon FLAT bowls--the kind you might use to keep turtles in--they have an enormous surface area for the Kombucha and have a nice lip around the opening to fit a rubber band around. Look for glass fish and reptile bowls at a pet shop or supplier for tropical fish and reptiles shops. Do not use glass fish tanks with silicone sealer on the inside of the joints, the silicone may leach into the ferment. Only use glass bowls that are molded or formed in one piece.

4.12 Can I use clay vessels to ferment the Kombucha Tea?

You have to make certain that any ceramic, or clay container you use, does not have a lead-based glaze on it (very common with imported items). Acidic substances cause the lead in the glaze to leach out into the liquid. There are tests kits available to determine whether your container has a lead glaze

4.13 Can I use an enamel pot to ferment Kombucha Tea?

A new or unchipped enamel pot can be used successfully to ferment Kombucha Tea. Just be certain that there are no chips in the enamel, because heavy metals underneath the enamel coating might leach into the acidic Kombucha Tea and cause heavy-metal poisoning.

4.14 Can I use Rubbermaid™ products?

Some people use Rubbermaid plastic containers to ferment and store their finished Kombucha Tea. These must be the hard, clear food-grade plastic containers that are used for storing wet acidic foods in the refrigerator.

4.15 Can I use a rubber container to ferment Kombucha Tea?

No. Do not use any rubber products to ferment and store your Kombucha Tea. Rubber is bad news even when mixed with plastics. It deteriorates easily and is prone to low pH.

4.16 Can I use glass Sun Tea jars with plastic spigots?

Many people use glass Sun-Tea jars with plastic spigots, reporting no deterioration of the spigots, even with continual use.

4.17 Can I use porcelain pots for fermenting Kombucha Tea?

People using porcelain containers should be very cautious. Make very sure there are no cracks, breaks, or chips in the porcelain finish of your pots that may come into contact with the fermenting liquid. In public health circles it has been known for some time that leaving acidic liquids in long-term contact with cracked or chipped porcelain can lead to heavy-metal poisoning. The use of cheaper metal materials under the enamel may contain heavy metals which may leach into the tea by the acids in the fermented tea.

4.18 Can I use a new plastic garbage can to store or ferment my Kombucha Tea in?

No. Do not use this type of plastic container for making or storing your Kombucha Tea. These containers are not food-grade plastic and might leach noxious chemicals (like petrochemicals) out of the plastic to contaminate your tea. If you must use plastic, only use a good food-grade polyethylene container that is suitable for storage of wet acidic foods.

4.19 How can I make Kombucha Tea in a large amounts?

The following advice was contributed by Günther W. Frank of Germany. "When I began to produce larger batches for my family, I bought two large stainless pots of 15 quarts each. However, this is time consuming and expensive to boil, for instance, 30 quarts (I think it is about 7 gallons) for the tea. This brought me to this idea: To avoid boiling such large quantities of tea, make a tea concentrate, and dilute it with normal tap water. For instance, if you want to get 4 gallons of tea, just boil 1 gallon of water, but use the tea quantity for 4 gallons of tea. Thus you get a tea concentrate. Fill up with 3 gallons of tap water, so you get 4 gallons of tea as nutrition liquid for your Kombucha beverage. If you have pretty good, clean water, there should be no concern to use this method."

Please Note: If your water is treated with chemicals or contains bacterial contaminants, do not use tap water without boiling it first.

4.20 Where can I buy food-grade plastics?

Most beer and wine making supply stores sell five-gallon plastic fermenting containers that are shaped like large buckets which have the same height to width ratio as a one-gallon pickle jar. Prolon makes containers of NSF (food grade plastic) of various sizes, with measurement increments (just like on a measuring cup). They can be purchased at "Sam's," or any restaurant supply stores.

4.21 Where can I find large food-grade plastic containers for making Kombucha Tea?

The Beer and Wine making supply stores sells a 5 gallon plastic fermenting container that is shaped like a large bucket that has the same height to width ratio as a one gallon pickle jar.

4.22 How important is it to use a glass container? I've heard that some people use plastic bowls.

Clear glass is the ideal container to use to brew and store Kombucha Tea because of the continuing uncertainty of plastic components leaching into the fermenting liquid. However, if you prefer to use plastic it must be food-grade, suitable for wet acidic foods. Some manufacturers like Prolon have an indicator on the product NSF. If in doubt, you should telephone plastic container manufactures to find out the composition of their product.

4.23 What are Sun Tea jars?

The Sun Tea jar is a one gallon glass jar the same size as a gallon pickle jar. It has a hole in the side about 1.5 inches from the bottom, with a plastic spigot and washer installed in the hole. I'm not sure about the composition of the spigot and washer, however, it is designed for making tea so it is probably food-grade plastic. They can be purchased at "Target," a discount store chain.

4.24 Can I use coloured glass or crystal containers to ferment my Kombucha Tea?

No. Coloured glass (also known as carnival glass or depression glass) contains its own toxins, and crystal bowls may contain lead.

4.25 Can I use Visions Cookware™ with the silverstone bottom?

Corning ™, makes "Visions" silverstone 5 quart glass pots. They have assured people that there is no metal in the coating on the bottom. It is a silicone-based Teflon surface. While it would be safe to use to prepare the tea solution, a plain glass bowl or jar should be used for fermenting.

4.26 Can I use stainless steel to brew my Kombucha Tea?

Only if it's of a high-grade (non-magnetic) stainless steel. If it can attract a magnet, then do not use it because the acidic tea will leach the metal out of it. It is preferable to use a glass container.

4.27 Can I use a Cast Iron pan to ferment my Kombucha Tea?a?

No, never use pots or containers made of cast iron or any other type of  reactive metal to ferment or store your Kombucha tea. KT is very acidic and  will leach iron molecules out of cast iron  and  contaminate your ferment.
The same applies to other pots or containers made of reactive metals such as iron, copper, aluminum, zinc, carbon steel and galvanized metal, etc., because acidic foods and liquids will leach metal molecules from  all of these containers and contaminate your KT.

You should only use non-reactive pots and containers to ferment or store  your Kombucha; some examples of non-reactive containers are, ceramic  (without lead or chips or cracks in the glazing), glass, stoneware pickling crocks, food-grade plastic,  wood,  and porcelain (again,  without chips or cracks only).

4.28 Can you tell me if there is any way to find out if a stoneware crock has lead?

If there is lead in your stoneware Kombucha will probably leach it out.  The best way to determine the lead content in stoneware is by XRF (x-ray fluorescence spectroscopy).  The analysis would cost more than a cabinet full of stoneware.  As Cyril suggested, lead test kits are available.  I have seen them in hardware stores.  For a positive determination you would need a crock that you know has lead in it to use as a control.   Lead can be found in a lot of old ceramic pieces.  Some of them are even radioactive. Don't risk it!

Bubbles and Health,


This Frequently Asked Questions (FAQ) is based, in part, on the personal experiences of the members of the Kombucha mailing list. It should not be regarded as a complete or definitive manual on Kombucha but rather as a collection of practical everyday answers to questions that come up when starting to make Kombucha Tea. This article is provided as is without any express or implied warranty. While every effort has been taken to ensure the accuracy of the information contained in this article, the authors/contributors assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein.

This FAQ may be posted to any USENET newsgroup, or BBS as long as it is posted in its entirety and includes this copyright statement, obligatory disclaimer, and authors name. This FAQ may not be distributed for financial gain. This FAQ may not be included in any commercial collections or compilations or posted on any commercial or non-commercial websites.

Permission is granted to freely copy this document in electronic form, or in print if the publication is distributed without charge, provided it is copied in its entirety without modification and appropriate credits are included. On the WWW, however, you must link here rather than copy it. Any other use requires explicit permission by the author.




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Designed Colleen M. Allen

Copyright 1996 - 2000 Colleen M. Allen  

Maintained by: Bob Williams [E-MAIL]
UpDt: 12/18/2000