Traditionally, kombucha is cultured using a continuous brewing system. Continuous-brew systems are easy to set up and have a number of benefits.
- A continuous-brew system is less maintenance. Adding fresh sweet tea to an existing jar already containing the starter tea and scoby is easier than starting with a new container.
- Maintaining the ecosystem created during the fermentation process provides the best defense against the development of mold and invasion by transient yeasts and bacteria.
- A continuous-brew system provides the healthiest environment for the scoby. Rather than disturbing the ecological environment through moving to new containers and regular cleaning cycles, the continuous brew allows the yeast and bacteria to develop relatively undisturbed with a consistent supply of new food.
- A continuous-brew system provides a more consistent supply of kombucha for your family. A specific amount can be harvested regularly.
Setting Up a Continuous Brewing System
Choosing Equipment. The only difference between a standard system and a continuous brewing system is the container used for brewing.
Size. A continuous brew container should hold between 1 and 5 gallons.
Material. Kombucha should be brewed in glass or porcelain. Avoid ceramic, plastic, crystal, and metal. Click here for more information on choosing the best material for your brewing vessel.
Spigot. A continuous brew container should have a spigot located near the bottom of the container so kombucha can be drawn off without disturbing the contents at the top of the container. Do not use a container with a spigot that has metal on the inside of the container.
Cover. A cover serves two purposes. It should allow the gases created during the fermentation process to escape while keeping out transient yeast and bacteria as well as pests such as fruit flies and ants. If the container does not have a built-in cover, use a tight-weave cloth or coffee filter, secured with a rubber band.
Cleaning. Clean everything thoroughly prior to setting up the brew system. Avoid anit-bacterial soap, and rinse with vinegar to remove soap residue.
Prepare the Kombucha Mixture. Prepare the sweet tea mixture according to this chart of ingredients, ratios, and instructions. Once the sweet tea is completely cooled and the starter tea or vinegar has been added, pour the mixture into the Continuous-brew container and add the scoby. Do not overfill the container. Only 80% of the vessel should be filled with liquid to allow space for the mother scoby, development of the new scoby, and circulation of gases.
Ferment the Kombucha. Ferment the kombucha for the desired period of time (Click here for more information on kombucha fermentation periods.)
Harvesting the Kombucha. Once the kombucha has fermented, remove the portion of the kombucha you wish to consume for the week and bottle the kombucha. Leave at least 20% of the kombucha in the vessel to act as starter tea for the next batch.
Feeding the Brewing System. Prepare new sweet tea using the normal ratios. Allow the tea to cool thoroughly, then slowly pour the solution into the top of the brew system to feed the system for the week. Again, only fill the container to 80% capacity.
Timing Harvesting and Feeding. Harvesting and feeding can be done every 3 to 14 days. We suggest weekly, to maintain a regular routine. If you wish to draw off kombucha to drink daily but only feed the mixture weekly, be aware that kombucha drawn off at the beginning of the week is likely to be sweeter than kombucha drawn off later in the week.
Controlling Sugar Content. It is a bit more challenging to control the sugar content of the kombucha when using a continuous-brew system. If low sugar content is an important factor for you, draw off all the kombucha you will require first before adding the fresh sugared tea. Allow the fresh sweet tea an adequate fermentation period prior to the next draw.
For example, if you require kombucha with a low sugar content, draw off 2 to 3 weeks' worth of kombucha from the brew system prior to adding fresh tea. Wait 2 to 3 weeks before the next draw, to ensure the batch has fermented sufficiently.
Ongoing Cleaning of the Brewing Vessel and Spigot. Cleaning the vessel and spigot is required only if the spigot becomes clogged with yeast particles or if too much yeast builds up in the bottom of the container.
To clean the system, remove the kombucha and scoby and set aside in a safe container. Clean the system thoroughly using white vinegar and warm water. Once the system is clean, add the kombucha and scoby back to the vessel, add fresh sweet tea, and resume the process.
The Large Scoby. One side effect of the continuous brewing system is the development of very large scobys. The primary issue with large scobys is that after some time they grow very thick and take up valuable space in the container. Reduce its size periodically, to allow more efficient fermenting. A very large scoby can be torn or cut up using a non-metal utensil, and pieces distributed to friends for making their own kombucha. Or, check out our list of ideas for using extra scobys.