As kombucha production moves from home brewing and small-scale trials to commercial production, filtration becomes an increasingly important part of the process.
Many people think that filtration is mainly used to make kombucha look clearer.
In commercial production, however, filtration has another important purpose: removing unwanted particles and protecting downstream equipment.
During fermentation and flavoring, kombucha may contain SCOBY pieces, yeast, fruit pulp, fruit fibers, tea particles, and other suspended solids. If these particles enter pumps, pipes, valves, or filling machines, they may cause blockages and unstable operation.
At the same time, more filtration is not always better.
Very fine filtration may affect the natural flavor, color, and mouthfeel of kombucha. It can also increase filter consumption and production costs.
So, how should a small commercial kombucha producer choose the right filtration method?
In this guide, we will introduce several common filtration options and explain where each one can be used.
Part 1: Why Does Kombucha Need Filtration?
Kombucha is a fermented beverage, so its composition is different from that of a typical soft drink or clear juice.
Depending on the recipe and production process, kombucha may contain:
- SCOBY pieces
- Yeast and yeast clusters
- Tea or plant particles
- Fruit pulp
- Fruit fibers
- Fermentation sediment
- Other suspended particles
For some kombucha products, a certain level of natural haze is part of the product style.
Therefore, the goal of filtration is not necessarily to make kombucha completely clear.
Instead, the goal is to remove unwanted particles while maintaining the desired flavor, appearance, and mouthfeel.
There is also another important reason for filtration:
- Filtration can protect downstream equipment.
Large SCOBY pieces, fruit pulp, or other particles may cause:
- Blocked pipes
- Blocked valves
- Unstable pump operation
- Blocked filling nozzles
- Filling machine downtime
- Rapid filter blockage
For this reason, a well-designed filtration system should consider not only the product, but also the entire production line.
Part 2: Bag Filters: A Practical First Step
Bag filters are one of the simplest and most practical filtration options for small commercial kombucha production.
The working principle is straightforward:
Kombucha enters the filter → the liquid passes through the filter bag → larger particles are retained by the bag.
Bag filters are therefore mainly used for coarse filtration or pre-filtration.
2.1 What can a bag filter remove?
Depending on the filter specification, it can help remove:
- SCOBY pieces
- Fruit pulp
- Tea particles
- Larger yeast clusters
- Larger suspended solids
This makes bag filtration especially useful for kombucha containing fruit, fruit pulp, or other solid ingredients.
2.2 Advantages of bag filters
Bag filters offer several practical benefits:
- Simple construction
- Easy operation
- Easy filter bag replacement
- Relatively low operating cost
- Different filtration grades are available
- Good protection for downstream filtration equipment
For example, a production line may use:
Fermentation Tank → Bag Filter → Buffer Tank → Fine Filtration → Filling Machine
The bag filter removes larger particles first, reducing the load on the finer filter downstream.
2.3 What are the limitations?
- Bag filters are mainly designed for larger particles.
- They are not normally intended to remove very fine yeast, colloids, or microorganisms.
Therefore, if a clearer product is required, additional filtration may be necessary.
Part 3: Plate Filters: For Further Clarification
Plate filtration, also known as plate and frame filtration, is a well-established filtration method used in beverage and brewing applications.
The liquid passes through filter sheets or filter media between the plates, while suspended solids are retained.
Compared with a basic bag filter, plate filtration can provide a higher level of clarification.
3.1 What can plate filters remove?
Depending on the filter media, they can help remove:
- Fine suspended solids
- Yeast
- Flocculated particles
- Smaller solid particles
For this reason, plate filters are often used for clarification.
A typical process could be:
Fermentation → Coarse Filtration → Plate Filtration → Filling
Or:
Fermentation → Bag Filtration → Plate Filtration → Fine Filtration → Filling
3.2 Advantages
One major advantage is flexibility.
Different filter sheets or filter media can be selected according to the required filtration level.
Plate filtration can therefore be a useful option for kombucha producers who want a cleaner and more consistent appearance.
3.3 What should be considered?
If the kombucha contains a large amount of fruit pulp or other large particles, it is usually better to remove these particles before plate filtration.
Otherwise, the filter media may become blocked quickly.
This is why coarse pre-filtration is often an important step before plate filtration.
Part 4: Cartridge Filters: Fine Filtration Before Filling
Cartridge filters are another common option for small commercial kombucha production.
Their main advantage is that they provide a clearly defined filtration rating.
Depending on the process, common filtration levels may include:
- 1 μm
- 0.45 μm
- 0.2 μm
The appropriate rating depends on the product, process, and requirements of the downstream filling equipment.
4.1 What is cartridge filtration used for?
Cartridge filters are generally better suited for removing smaller particles that remain after coarse or clarification filtration.
They should not normally be used as the first filter when the kombucha contains a large amount of fruit pulp or SCOBY material.
A practical combination can be:
Bag Filter → Cartridge Filter → Filling Machine
The bag filter handles the larger particles, while the cartridge filter provides finer filtration.
4.2 Is finer filtration always better?
No.
A finer filter may provide a clearer product, but it can also result in:
- Higher filter consumption
- Faster blockage
- More product loss
- Possible changes in flavor or mouthfeel
For example, a 0.2 μm filter is not automatically “better” than a 1 μm filter.
The correct filtration level should be selected according to the actual product requirements.
If a kombucha brand wants to keep a natural appearance and character, excessive filtration may not be the best choice.
Part 5: Diatomaceous Earth Filtration
Diatomaceous earth filtration has been widely used in beer and beverage production for many years.
Diatomaceous earth forms a porous filtration layer that can capture fine particles from the liquid.
It can provide good clarification and is suitable for relatively large processing volumes.
However, for small commercial kombucha production, its suitability should be evaluated carefully.
Factors to consider include:
- Production capacity
- Equipment investment
- Operating complexity
- Filter media consumption
- Waste handling
Used diatomaceous earth also needs to be handled and disposed of properly.
For many 500 L or 1,000 L-class commercial kombucha systems, a combination of bag filtration, plate filtration, or cartridge filtration may already meet the production requirements.
Therefore, a diatomaceous earth system is not necessarily required for every kombucha production line.
Part 6: Other Filtration and Separation Technologies
Larger industrial beverage plants may also use more advanced separation technologies.
6.1 Depth Filtration
Depth filters use a thick filtration medium to capture particles throughout the depth of the filter.
They can be used for clarification or as a pre-treatment step before finer filtration.
6.2 Centrifugal Separation
Centrifugation is not technically a filtration method. Instead, it uses centrifugal force to separate yeast and solid particles from the liquid.
It can be useful for large-scale, continuous beverage production where high throughput is required.
For small commercial kombucha systems, however, such equipment may not always be necessary.
6.3 Membrane Separation
Large industrial beverage plants may also use membrane technologies such as microfiltration or ultrafiltration.
These systems can provide very fine separation, but they also require higher investment, careful membrane cleaning, and good control of upstream filtration.
For small commercial kombucha production, the benefits should be evaluated against the additional cost and complexity.
Part 7: Comparing Different Kombucha Filtration Methods
| Filtration Method | Main Purpose | Typical Target | Typical Application |
| Bag Filter | Coarse filtration | Fruit pulp, SCOBY pieces, large particles | First-stage filtration |
| Plate Filter | Clarification | Yeast, flocs, fine suspended solids | Clarification |
| Cartridge Filter | Fine filtration | Small suspended particles | Final filtration / filling protection |
| Diatomaceous Earth | Deep clarification | Fine suspended solids, yeast | Larger commercial production |
| Depth Filter | Clarification / pre-filtration | Fine particles | Pre-treatment before fine filtration |
| Centrifuge | Solid-liquid separation | Yeast and larger solids | Large industrial production |
Part 8: How Should You Choose a Filtration System for Kombucha?
There is no single “best” filtration method for every kombucha product.
The right solution depends on several factors.
8.1 Do you want a clear or naturally hazy product?
If the product is designed to have a natural appearance, removing only larger unwanted particles may be enough.
If a clearer appearance is required, additional clarification may be necessary.
8.2 Does the product contain fruit or pulp?
If the recipe contains:
- Fruit pulp
- Fruit pieces
- Cold-pressed juice
- Plant ingredients
then coarse filtration becomes especially important.
8.3 What filling equipment will you use?
Different filling machines have different requirements for particles and suspended solids.
For example, fine particles may affect filling valves or nozzles, while larger particles can cause even more obvious blockage problems.
Therefore, filtration should be considered together with the filling system.
8.4 How important is flavor retention?
Kombucha flavor comes from tea, sugar, organic acids, and many compounds produced during fermentation.
The filtration system should therefore not only answer the question:
“How clear can we make the product?”
It should also answer:
“What kind of kombucha do we want to produce?”
Part 9: Practical Filtration Combinations for Small Commercial Kombucha
For small commercial systems, a few practical combinations can be considered.
Option 1: Simple Coarse Filtration
Fermentation Tank → Bag Filter → Filling
Suitable for:
- Naturally hazy kombucha
- Products where only large particles need to be removed
- Simple production processes
The main purpose is to remove unwanted large particles and protect downstream equipment.
Option 2: Coarse + Fine Filtration
Fermentation Tank → Bag Filter → Cartridge Filter → Filling
Suitable for:
- Products requiring lower suspended solids
- Products where filling stability is important
- Applications where larger particles need to be removed before fine filtration
The bag filter reduces the particle load, while the cartridge filter provides finer filtration.
Option 3: Coarse + Clarification + Fine Filtration
Fermentation Tank → Bag Filter → Plate Filter → Cartridge Filter → Filling
Suitable for:
- Products requiring higher clarity
- Commercial products with more demanding appearance requirements
- Applications where filling equipment needs stronger protection
This combination provides step-by-step filtration, from larger particles to finer suspended solids.
Part 10: Filtration Is Not About “The More, the Better”
One common mistake is to assume that adding more filtration will always produce a better product.
In reality, filtration should be designed as a complete process.
If a product contains a large amount of fruit pulp but goes directly into a very fine cartridge filter, the filter may become blocked quickly.
If a plate filter has already achieved the required clarity, adding another extremely fine filtration stage may not provide enough additional benefit to justify the cost.
And if the product is intentionally designed to retain some natural haze and flavor, excessive filtration may change the character of the finished kombucha.
Therefore, a good filtration system should balance:
Product Quality + Flavor + Filling Stability + Operating Cost
The goal is not to make kombucha “as clear as possible.”
The goal is to achieve the right level of filtration for the product and the production process.
Part 11: Conclusion
As kombucha production moves toward commercial scale, filtration becomes an important part of the overall process design.
For small commercial kombucha production:
- Bag filters are practical for removing fruit pulp, SCOBY pieces, and larger particles.
- Plate filters can provide additional clarification when a cleaner appearance is required.
- Cartridge filters can provide finer filtration and help protect filling equipment.
For larger industrial plants, technologies such as diatomaceous earth filtration, depth filtration, and centrifugation may also be considered depending on production capacity and process requirements.
There is no single filtration method that works best for every kombucha product.
The right solution should be designed around the entire process — from ingredients and fermentation to flavoring, filtration, and final filling.
For kombucha producers moving from pilot production to commercial manufacturing, designing the filtration process early can help improve product consistency, reduce equipment blockage, and make daily production more stable.
If you are planning a commercial kombucha production line, share your production capacity, product type, use of fruit or juice, and filling method with us. Our team can help evaluate a suitable filtration solution for your process.
Kombucha Filtration
