Dairy processing imposes consistently demanding requirements on liquid mixing equipment. Products range from low-viscosity fluid milk through to high-fat cream, cultured yoghurt bases, viscous spreadable blends, and reconstituted infant formula — each requiring reliable, hygienic mixing that meets dairy-specific regulatory standards. High shear mixing, which applies intense mechanical and hydraulic forces at a rotor-stator gap, has become the standard across many of these applications because it achieves stable emulsions, consistent particle size distribution, and rapid dispersion in a single pass.
Advanced Packaging Systems (APS) is the New Zealand distributor for Silverson Machines, whose high shear mixer range covers dairy liquid processing from laboratory development through to large-scale industrial production.
Silverson FMX5
How High Shear Mixing Works in Dairy Applications
Silverson mixers operate on the rotor-stator principle. A precision-engineered rotor spins at high speed within a close-tolerance stator. Dairy product is drawn axially into the workhead and expelled radially at high velocity, experiencing intense shear, turbulence, and cavitation as it passes through the stator apertures. The energy delivered at the rotor-stator gap is far in excess of what paddle, anchor, or ribbon agitators can achieve — enabling processes such as homogenisation and emulsification that require genuine mechanical shear rather than bulk fluid movement.
Key Dairy Processing Applications
Milk and Cream Homogenisation
Homogenisation in dairy processing reduces fat globule size to prevent cream line separation and produce a product with uniform appearance and consistent texture. Silverson inline mixers process milk and cream in a single pass through the pipeline, delivering controlled shear conditions that produce a stable emulsion without requiring separate high-pressure homogeniser equipment. For processors running continuous production lines — dairies, co-packers, or ingredient processors — inline high shear processing simplifies the homogenisation stage and reduces equipment footprint.
Yoghurt and Cultured Dairy Products
Yoghurt base production involves the dispersion of milk solids, stabilisers, and thickeners into the liquid phase before incubation. Achieving a smooth, lump-free base is critical — undispersed stabiliser or milk solid agglomerates survive incubation and create texture defects in the finished product. Silverson batch mixers process yoghurt bases rapidly, incorporating stabilisers such as gelatine, starch, or pectin completely into the liquid before culture addition. The BX batch mixer range suits the varied batch sizes and frequent product changeovers typical of yoghurt manufacturing.
Silverson High Shear Lab Mixer
Recombined Milk and Cream Concentrates
Dairy markets outside producing regions rely on recombined milk — whole milk powder or skim milk powder reconstituted into fluid milk for distribution. This process requires rapid, uniform incorporation of powder into the liquid phase without agglomeration. The Silverson Flashmix is specifically designed for this application: powder is drawn directly into the high shear zone at the rotor-stator gap, fully wetted before it contacts the bulk product. This eliminates floating lumps and incompletely dispersed agglomerates associated with conventional agitation. The Flashmix achieves powder incorporation rates of up to 227 kg per minute and is 3-A certified for dairy applications.
Flavoured Dairy Beverages and Nutritional Products
Flavoured milk, dairy-based nutritional supplements, and fortified beverages require consistent dispersion of flavour concentrates, vitamins, minerals, and protein fractions. These ingredients vary widely in solubility, surface chemistry, and particle size — conditions that suit high shear processing. Silverson inline mixers are used on continuous flavoured beverage lines, processing product at throughput rates matched to filling equipment downstream, with consistent quality across extended production runs.
Butter and Spreadable Products
Butter processing and the production of reduced-fat spreads and dairy-based dressings involve the emulsification of water-in-fat or fat-in-water emulsion systems. Silverson mixers produce stable emulsions at the desired droplet size range, controlling texture and mouthfeel in a process that is difficult to achieve by low-shear agitation alone.
High Shear Mixers & Homogenisers.
Inline vs Batch High Shear Mixing in Dairy
The choice between inline and batch configurations depends on production volume, formulation variety, and process flexibility requirements.
Inline high shear mixers are installed directly in the product pipeline. Product passes through the mixer continuously, receiving controlled shear with each pass. For large-volume operations — multi-thousand litre runs of a consistent recipe, such as UHT milk or cream — inline processing delivers consistent product quality with minimal operator intervention. Energy consumption per unit of product is typically lower than equivalent batch processing.
Batch mixers work in process vessels, bringing the mixing head directly to the product. They suit operations with varied formulations, smaller batch sizes, or multi-stage processes where ingredients are added progressively. The Silverson BX range covers batch sizes from pilot scale to multi-tonne industrial production, and is designed for hygienic operation with full CIP validation. Bottom entry mixers provide an alternative for large-volume dairy vessels, operating through the base of the tank and eliminating the need to open vessels during mixing — an advantage in enclosed, temperature-controlled process environments.
Planning a processing or packaging project?
Speak with Advanced Packaging Systems about equipment selection, line integration, and local support in New Zealand.
- Local technical and commercial support in New Zealand.
- Obligation-free advice on equipment and line fit.
- Useful next steps, even if your project is still early-stage.
Sanitary Design and Regulatory Compliance
Dairy processing equipment must comply with hygiene standards governing surface finish, seal design, material selection, and cleanability. Silverson’s dairy-grade mixers are constructed in 316L stainless steel with electropolished product contact surfaces, meeting Ra surface finish specifications appropriate for food and dairy applications. Designs support EHEDG hygienic engineering principles and 3-A sanitary standards — the recognised benchmarks for dairy processing equipment in markets including the USA, the European Union, Australia, and New Zealand.
Clean-in-place validation is achievable with standard Silverson dairy configurations, eliminating the need to dismantle the mixer for routine cleaning. This is a critical operational requirement in facilities running multiple products per shift or operating under strict HACCP and food safety management frameworks.
The Silverson Range for Dairy Processing
The Silverson product line provides options at every production scale. The L5M-A laboratory mixer allows process development, scale-up trials, and formulation validation at bench scale. Pilot-scale batch and inline mixers bridge the gap between laboratory and production. Full-scale production units — the BX batch range, standard inline series, Flashmix, and bottom entry mixers — cover the full range of dairy liquid processing applications at commercial throughput.
For operations requiring hygienic design with full documentation packages — FDA, MPI, or EU food safety compliance — Silverson’s pharmaceutical and dairy equipment lines are available with the appropriate materials certifications, surface finish verification, and CIP qualification support.
High Shear Mixing Equipment in New Zealand
Advanced Packaging Systems is the authorised New Zealand distributor for Silverson Machines, providing equipment specification support, process consultation, spare parts, and local technical service. Contact APS to discuss your dairy mixing requirements.
