0.2 µm vs 0.45 µm Membrane Filters: Understanding LRVs in Beverage Filtration

When selecting a final membrane filter for a beverage process, it can be tempting to assume that the smallest pore size will always deliver the best result. In practice, the right choice depends on the product, the microbial risks involved, the required level of control and the performance expected from the filtration line.

Both 0.2 µm and 0.45 µm membranes have an important role in beverage production. Understanding their differences, together with the Log Reduction Values behind their validated performance, helps producers select a membrane that protects product quality without placing unnecessary restrictions on production.

What Does a Membrane’s Micron Rating Tell Us?

A membrane’s micron rating refers to the pore size used to classify the filter. A 0.2 µm membrane has a smaller stated pore size than a 0.45 µm membrane, but pore size alone does not establish how effectively a filter will retain a particular microorganism.

Performance can also be influenced by membrane construction, filter material, operating conditions and the organism used during validation. This is why two filters with similar stated micron ratings may not provide the same retention performance.

For more detail on how construction, porosity ratings and retention efficiency affect filter performance, read our article: Choose The Right Filter For Your Application.

What Is a Log Reduction Value?

A Log Reduction Value, or LRV, describes the reduction in the number of microorganisms achieved under defined test conditions.

The percentage reduction increases with each log level:

• 1-log reduction: 90%
• 2-log reduction: 99%
• 3-log reduction: 99.9%
• 4-log reduction: 99.99%

These percentages are outlined in the Australian Drinking Water Guidelines (National Health and Medical Research Council, 2025).

A higher LRV indicates a greater demonstrated reduction. However, the result must be considered alongside the microorganism used, the initial challenge level and the conditions under which the filter was tested.

An LRV is not a universal score that applies equally to every microorganism. When comparing membrane filters, producers should review validation results for the organisms relevant to their product and process.

How Do 0.2 µm and 0.45 µm Membranes Compare?

In wine production, membrane filters are commonly used as a final filtration stage after clarification and pre-filtration to remove smaller microorganisms before packaging (Australian Wine Research Institute, n.d.).

A validated 0.45 µm membrane may provide the required control for relevant yeast and bacteria in many wine and other beverage applications.

Bottled water presents different considerations. Unlike wine, which contains alcohol, or beverages that use carbonation, preservatives or additional treatment processes, bottled water may have limited or no residual antimicrobial protection after filling. This places greater importance on validated bacterial retention and hygienic filling conditions.

A validated 0.2 µm membrane may therefore be appropriate for bottled-water applications where tighter bacterial control is required. In some cases, where a specific challenge involving smaller bacteria has been identified, an even tighter 0.1 µm membrane may be considered. Selection should always be based on organism-specific validation data and the requirements of the process.

Organism-specific validation results provide more meaningful insight than pore size alone. As one example, published technical data for a beverage-grade membrane in BHF’s range lists the following results:

• Escherichia coli: greater than 9 LRV for both 0.2 µm and 0.45 µm
• Lactobacillus brevis: greater than 9 LRV for both grades
• Saccharomyces cerevisiae: greater than 7 LRV for both grades
• Brettanomyces: greater than 6 LRV for both grades
• Serratia marcescens: 9 LRV at 0.2 µm and 8 LRV at 0.45 µm
• Brevundimonas diminuta: 6 LRV at 0.2 µm, with no corresponding result listed for the 0.45 µm grade

These results illustrate why the target microorganism should guide membrane selection. A tighter membrane may provide additional protection where smaller bacteria present a specific risk, but it is not automatically required for every beverage application.

Selecting the Right Membrane

Choosing between 0.2 µm and 0.45 µm should begin with the product and process requirements. Producers should consider:

• The microorganisms relevant to the product
• The required LRV
• Other microbial protection measures within the product and process
• Shelf-life and packaging requirements
• Required throughput and batch volume
• Product viscosity and filterability
• Existing clarification and pre-filtration
• Cleaning, sanitisation and integrity-testing procedures

Other microbial protection measures may include alcohol, carbonation, preservatives, low pH, thermal treatment or hygienic packaging conditions. These factors can influence the level of microbial retention required from the final membrane.

Effective pre-filtration is also important because surface membrane filters gradually block as retained material accumulates. AWRI advises that prior depth filtration or sacrificial filtration with a larger pore size is normally required to help prevent membrane clogging (Australian Wine Research Institute, n.d.).

The BHF Perspective

At BHF, we work with beverage producers across Asia Pacific to assess the complete filtration process rather than selecting a membrane based only on its pore size.

“Choosing between a 0.2 µm and 0.45 µm membrane is not simply about selecting the finer option. It requires understanding the microorganisms relevant to the product, reviewing the validated LRV data and ensuring the membrane can still deliver the throughput and filter life required by the process.” says Devan Wesley, National Sales Manager at BHF.

BHF’s beverage membrane range includes BEVPOR PH, BEVPOR PS and SupaPore VPWS, with 0.2 µm and 0.45 µm grades, among other ratings, available for different beverage applications.

Explore our full membrane filtration range here to view alternate options or for a more tailored review or your current filtration requirements, contact your local team.