The Filtration Focus: October 2026 Edition

A tank might be hygienically designed, regularly cleaned and filled with a high-quality product.

But every time that tank fills or empties, it has to exchange air.

And that creates a potential contamination pathway.

When liquid enters a tank, the displaced air needs somewhere to go. When the tank is emptied, air is drawn back in to replace the lost volume.

The question is: what comes back in with it?

A correctly specified vent filter can help prevent airborne particles and microorganisms from entering the vessel while still allowing the tank to breathe freely.

It's not simply about choosing a 0.2 µm filter.

There are several things that need to work together:

💧 Hydrophobicity

Condensation, humidity and steam can wet a membrane. A wetted vent filter can significantly restrict airflow, which is why hydrophobic membrane materials such as PTFE are commonly used for sterile air and tank vent applications.

🌬️ Airflow

The filter has to cope with air moving both into and out of the tank. Restricting airflow can create pressure or vacuum conditions within the vessel.

📉 Pressure Drop

A filter that looks appropriate on paper may not be appropriate at the required flow rate. Filter area, membrane construction and housing design all influence pressure drop.

♨️ CIP / SIP Exposure

Where steam sterilisation is involved, the filter needs to be suitable for the temperature and sterilisation regime. Steam cooling and condensation can also create significant vacuum conditions within a tank.

🦠 Microbial Retention

For hygienic applications, the filter isn't simply stopping visible dust. The required level of microbial retention needs to be considered alongside the application and validation requirements.

🔬 Integrity Testing

For critical sterile applications, the ability to verify filter integrity can become an important part of the overall process.

Pall highlights that incorrect vent-filter sizing can restrict airflow and, in extreme cases, contribute to filter collapse, rupture-disc activation or tank deformation. Other sterile filtration manufacturers similarly specify hydrophobic PTFE membranes for their resistance to wetting and suitability for repeated sterilisation.

So, when did you last review your tank vent?

Not just the cartridge.

• The airflow.

• The pressure drop.

• The tank volume.

• The fill and draw-down rate.

• The CIP/SIP conditions.

And what happens when the filter starts to load.

Because sometimes the right filter isn't the one with the smallest micron rating.

It's the one correctly matched to the whole application.

Water is becoming an increasingly important production consideration for food and beverage manufacturers.

It's not simply about reducing the amount of water used.

The bigger question is becoming:

Can water that would previously have been discharged be treated and safely reused somewhere else in the process?

Recent European work has been looking directly at this challenge. The EU-backed AccelWater project investigated water recovery and reuse across food and beverage applications, combining technologies including clarification, membrane filtration, reverse osmosis, polishing, disinfection and biological treatment.

Its reported demonstrations achieved up to 95% water recovery and 93% wastewater reuse, alongside improvements in overall water and resource efficiency.

Meanwhile, the US EPA's 2026 Water Reuse Action Plan specifically includes developing a decision-making framework for water reuse in food and beverage production.

What does this mean for filtration?

Water reuse isn't one filtration step.

A reuse system could involve several stages:

Process water

↓

Prefiltration

↓

Membrane / RO treatment

↓

Storage

↓

Polishing

↓

Disinfection

↓

Reuse application

Different points in the process require different filtration strategies.

For example, filtration might be required to:

• Protect downstream membranes
• Reduce suspended solids
• Protect pumps and equipment
• Polish recovered process water
• Protect RO systems
• Remove organic contaminants through carbon
• Improve water quality before reuse
• Control microbiological contamination where appropriate

The opportunity isn't simply "more water treatment."

It's better filtration throughout the water cycle.

As manufacturers look at water availability, operating costs and sustainability together, filtration specialists can play a role much earlier in the conversation — helping determine where filtration adds the most value, rather than simply supplying a replacement cartridge.

Could water currently leaving your process have another useful destination?

Low and no-alcohol beverages continue to create opportunities for breweries, wineries and beverage manufacturers.

But removing alcohol also removes one of the hurdles that can contribute to product stability.

That changes the filtration challenge.

Alcohol-free and low-alcohol products can require careful management of:

• Microbiological stability

• Clarity

• Colloidal stability

• Shelf life

• Flavour and product character

Current industry guidance highlights the role of upstream clarification alongside validated final membrane filtration for maintaining stability in alcohol-free and low-alcohol wine.

The same principle can apply across beverage production:

Clarification → Prefiltration → Membrane Filtration → Sterile Gas → Tank Venting → Final Protection

The important point is that filtration shouldn't be considered as one isolated step at the end of the process.

It can form part of a series of contamination-control and product-quality barriers.

For breweries in particular, filtration considerations can extend from raw water and utilities through clarification and final filtration, with air, gas, water and CO₂ all representing potential contamination routes if not appropriately managed.

Less alcohol doesn't necessarily mean a simpler process.

It can mean the opposite.

As one protective hurdle is reduced, the rest of the process has to work harder.

A filter blocks.

The first reaction is often:

"We need a higher micron rating."

But what if the filter isn't actually the problem?

A cartridge reaching high differential pressure unusually quickly could be telling you something about the process.

Before changing the filter, ask:

Has the incoming particle load changed?

A change in raw materials, water quality or upstream processing could increase the load reaching the filter.

Has the flow rate increased?

More flow can mean greater pressure drop and faster loading.

Has production changed?

A process that originally ran at one throughput may behave very differently after a capacity increase.

Is the prefiltration doing enough?

A final membrane or polishing filter shouldn't necessarily be expected to handle a particle load that could have been removed upstream.

Has the product changed?

Viscosity, solids concentration, formulation or temperature can all affect filtration performance.

Is the micron rating actually appropriate?

Going finer isn't automatically better. A smaller pore size can provide greater retention, but may also increase pressure drop or reduce service life.

This is where filtration becomes an engineering question.

Instead of:

"Which filter do you normally buy?"

Ask:

"What is happening before the filter?"

Pressure drop and flow data are increasingly being used to understand filter loading and support predictive maintenance approaches. Research and recent developments are looking at using these parameters to identify obstruction and estimate when a filter may require maintenance or replacement.

That doesn't mean every filtration system needs sophisticated monitoring.

Sometimes the answer is much simpler:

• Look at the process.

• Look at the filter history.

• Look at the differential pressure.

• Look at the flow rate.

• Then change the specification.

• The best filter isn't always the finest filter.

It's the filter that performs reliably within the process it's actually being asked to handle?