There are a variety of containers to store our food, but when it comes to kombucha you must be cautious, since the materials approved by a margin of safety are quite small.
Containers suitable for food use and indicated for fermented foods are a great option, even so, it is necessary to know better which of these meets the necessary characteristics to withstand the acid fermentation of kombucha, in addition to protecting it from microbial contamination.
Contents
What would be the ideal kombucha containers?
Glass containers suitable for food use are best suited for fermentation and storage of kombucha, they are able to withstand pH changes without being affected and without altering the components of the beverage unlike other containers. Larger bottles are ideal for better SCOBY development. [1] [2]
Of the materials used to ferment or store kombucha such as stainless steel, high-density polyethylene (HDPE) and propylene (PP), glass materials are the only ones that do not represent a biological hazard as they are not affected by the acidity of kombucha, since the low pH can corrode the metal or generate leaching of the toxic constituents of the other containers. [1][3]
As for the dimensions, large wide-mouth bottles are recommended, ideally vases, they can be glass or ceramic without lead glaze. These characteristics are suitable for the formation of a new SCOBY during fermentation to leave a greater surface area in relation to the volume allowing a greater uptake of oxygen for its growth. [4]
What types of bottles can you use?
When you are going to choose a bottle, in case you are going to carbonate the drink, avoid that they are square or angled since they are made to store liquids without gas being more prone to explode, and do not use glass jars since they are designed to seal under vacuum and not to withstand pressure.
The amber bottles prevent the contents of the bottle from being seen, but favor fermentation if the place is exposed to sunlight. In other cases you can reuse commercial bottles of kombucha, it can be comfortable for beginners having the opportunity to try different brands, styles of bottles and caps.
There are bottles that come with screw caps, some can be very useful for carbonation, conical lids of LDPE plastic or foam core made with LDPE film are effective, although the latter need a very tight seal, but they are cheaper. [5]
Personally, I use bottles of wine with screw caps for the harvest of kombucha, although I also use them if I am going to carry out a second fermentation.
For carbonated beverages
For the first fermentation you can use the type of bottle already mentioned, but in case you are going to carbonate the kombucha with a second fermentation it is necessary to use hermetic bottles, those of the grolsch type or with mechanical cap are effective for closing very well and having the ability to release excess pressure safely.
Inexperienced people can use small bottles of 400 to 500 ml.
Bottles can explode due to carbonation, becoming dangerous and very disastrous, which is why containers must be made of quality glass made to withstand pressure or you can use food-grade plastic bottles, something we talk about in the guide on how to carbonate kombucha.
When the secondary fermentation is finished, it must be transferred to glass bottles and kept at a low temperature to avoid fermentation. [5]
Can Mason-type jars be used?
Transparent mason glass jars are also recommended, they are considered ideal for fermented. These Mason bottles are varied, ideal for many types of fermented, the 4 liters are very good for both experts and beginners, they are excellent to follow the fermentation process. [5]
In fact, I use containers like these mason-type jars, which you can see in my photograph, with the exception that it has a valve to remove the liquid at ease.
When are steel containers used?
They can be used for preparation or storage as long as these are made of stainless steel, are considered the most suitable and almost mandatory to prepare kombucha after glass containers, as well as being useful for preparing kombucha at industrial levels. [6]
Metal containers should not have scratches or cracks that may harbor pathogenic microorganisms. In addition, it is necessary that they are made of stainless steel, since, otherwise, they can react with the acid of the kombucha dissolving the metal and leaking into the drink, therefore, they can present a strange color or flavor with these containers. [7]
Commercially produced kombucha is prepared in high-quality, very large stainless-steel containers, yet it has been believed that kombucha should not approach any metal containers, including stainless steel ones. This is misunderstood because low-quality metal can corrode in the presence of strong acids.
While this is true, it does not apply to stainless steel, it also only represents a problem when it is a prolonged time in contact with the acid as a storage container, but if it is good quality stainless steel with a grade equal to or greater than 304 it is perfect for fermentation, mainly in industry. [5]
What risks exist depending on the container used?
While the physical risks are lower in making homemade products compared to commercial ones, there may still be some physical or contamination hazard. For example, alcoholic fermentation can increase the risk of explosion of bottles and cans used for storage. [8] [9]
When kombucha is to be carbonated, if the proper container is not used there is a possibility that the bottle will explode, causing physical damage to the individual who handles it and damage to property. It is possible to reduce the risk by using a resistant material and by cooling the product slowing down the second fermentation.
It is possible that reusing containers of other types of fermented beverages can generate cross-contamination, an example would be craft beer and strong cider. That is why in industries an investment must be made to have containers exclusively for kombucha, you must use non-reusable glass or stainless-steel containers for sale. [2]
Inspection of the bottles to be used.
A visual inspection of the storage container to be used for any food is necessary, verifying that the structure is intact, the appropriate lids must also be used to properly seal the container. [5] [8]
For storage, the ideal is to only use glass bottles because they reduce the risk of chemical contamination, even so, you must ensure that they are not defective (chipped, cracked, broken, etc.) due to the high probability of breaking during storage or preparation of kombucha. [8] [10]
You should check that they are bottles with thick glass, texture and a narrow diameter, these bottles are less likely to break. As for screw caps, you should use plastic caps, completely avoid caps made of aluminum or any other material capable of deforming under pressure. [5] [10]
What precautions should be taken with the used container?
You must follow the prevention measures indicated for the fermentation of kombucha, which some involve the safety and stability of the container used, avoiding risks of explosions or damage to the material due to acidity. [5] [10]
Bottled kombucha that is going to be aged should not have more ingredients added (sugar or fruit) because they explosively increase carbonation. It is also dangerous if you shake the bottle, they must remain in low temperature places, such as the refrigerator, reducing the fermentation rate, where if it is going to be stored for a long time, you must open it from time to time to release the CO2. [10]
Also keep them in closed and secluded places decreases the risk of being affected by the environment, any blow that can damage the bottle or cause it to fall off the shelf, in any way, it is better to prevent and have several clean jars available, they are useful to separate the SCOBY from the liquid already fermented in case of any accident. [5]
Why is it dangerous to use ceramic containers?
Ceramics and other containers may contain lead or other toxins which can leach due to the high acidity of some beverages, contaminating them and causing poisoning problems in consumers, even causing death. [4] [11]
Kombucha can cause leaching of ceramic components due to the high concentration of acetic acid that increases the acidity of the beverage. Lead is at very low levels, so it is not dangerous unless it is immersed for a long time in the acid of the kombucha reaching to dissolve large amounts of lead in the liquid. [12]
Cases of elevated blood lead levels have been found where samples taken showed that they came from kombucha with a content of 173 mg / kg of lead, which subsequently immersed in a ceramic pot was able to reach 329 mg / kg, when only less than 0.2 mg / kg of lead is allowed in food. [11]
For this reason, avoid problems and use thick glass containers, and goodbye to problems.
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