RF Tempering & Defrosting

Defrost in minutes,
not days

Global Food Technology is the UK and Ireland supplier of Stalam industrial radio-frequency thawing and tempering equipment for meat, poultry, fish, seafood, fruit and other frozen food products.

The technology

What is RF defrosting?

Radio frequency (RF) defrosting is a thermal-processing technology that dissipates electromagnetic energy inside a frozen product.

Unlike air, water or conventional methods — where heat is transferred from the surface inwards by conduction, convection or irradiation — an RF field generates heat directly and instantaneously throughout the entire product mass. This is why the mechanism is described as "endogenous" or "volumetric" heating, and it is what allows a rapid, uniform and accurately controlled defrost regardless of the product's size, weight, shape or thermal conductivity.

Stalam COLDWAVE+ radio frequency in-line defrosting system
The Stalam COLDWAVE+ RF defroster — product passes continuously through the RF tunnel on a conveyor belt.
Step by step

How RF defrosting works

01

Product enters the RF field

Product travels on a conveyor belt continuously through the RF tunnel, between an upper and a lower metal plate. These plates form an electrical capacitor, and the product between them becomes the dielectric element.

02

The field reverses millions of times a second

The plates connect to an RF generator oscillating at 27.12 MHz. The polar water molecules in the frozen product vibrate and rotate as they try to align with the rapidly reversing field polarity.

03

Heat is generated inside the product

That molecular friction generates heat rapidly and uniformly within the whole mass at once — not from the outside in. Because water is highly polar, RF heats frozen, water-bearing food extremely efficiently.

04

The process is precisely controlled

Heat and defrosting time are controlled accurately through the voltage on the plates and the conveyor belt speed, so product reaches exactly the target temperature for the next process.

Why processors switch

The benefits

8%
higher yield by eliminating the drip loss of conventional defrosting.
Typical payback: 6–12 months

Minutes, not days

Even large blocks temper in minutes — and can be defrosted still inside their packaging.

No degradation

Speed and uniformity prevent bacterial growth and preserve texture, colour and quality.

In-line & just-in-time

Continuous operation integrates into the line, with flexibility for sudden or changing orders.

Less floor space

A fraction of the footprint of defrosting rooms, with no energy lost to ambient air.

Applications

What can be defrosted?

Radio frequency defrosting of frozen meat

Meat & Poultry

Blocks and individual cuts, bone-in or boneless, lean or fat, naked or packaged — beef, pork, lamb, chicken and turkey. Tempered ready for grinding, slicing, dicing, forming, tumbling or marinating.

Radio frequency defrosting of frozen fish and seafood

Fish & Seafood

IQF and blocks, whole fish, fillets, portions and minced fish, flat and round, with or without packaging. The gentle process preserves the physical, biological and nutritional integrity of fish and shellfish.

Radio frequency defrosting of frozen vegetables

Fruit & Vegetables

All kinds of frozen fruit and vegetables — IQF or in blocks, bulk or packaged. RF tempering minimises drip loss so produce keeps its texture, flavour and freshness. Carrots, peas, spinach, strawberries and more.

Bottles of milk and dairy products

Ready Meals, Dairy & Liquids

Ready meals for catering and retail, butter, margarine, soft cheese, liquid egg, fruit purées, juices and vegetable soups. Even delicate packaged products defrost evenly and gently, ready for the next step.

See RF defrosting in action

Real Stalam COLDWAVE+ installations defrosting frozen product by radio frequency.

Meat blocks

Fish & seafood (frozen prawns)

The range

The Stalam COLDWAVE+ range

Global Food Technology supplies the Stalam COLDWAVE+, the market-leading in-line RF defroster. With more than 2,600 Stalam RF machines in operation across 70+ countries, the COLDWAVE+ is available from compact 7 kW units to high-capacity 105 kW systems. The latest COLDWAVE+ 2.0 generation adds a 5-position mobile upper electrode for greater versatility, an improved hygienic design for easier cleaning, energy-saving stand-by, and advanced on-board diagnostics.

Model Cooling Belt width Throughput to -3/-1°C Throughput to -6/-4°C
7 kWAir0.6 m150–200 kg/h250–300 kg/h
20 kWAir1.4 m400–600 kg/h800–1000 kg/h
40 kWAir or water1.4 m800–1200 kg/h1500–2000 kg/h
85 kWWater1.8 m1500–2000 kg/h3000–4000 kg/h
105 kWWater1.8 m1500–3000 kg/h3000–5000 kg/h

Throughput varies with product type, weight and target temperature. Figures based on 90% vl beef trimming blocks (55×35×18 cm, 27 kg) at -18°C. Multiple modules can be combined to increase capacity as production grows.

Radio frequency defrosting FAQ

Straight answers to the questions food processors ask most often about RF defrosting, tempering and equipment.

What is radio frequency (RF) defrosting?

Radio frequency defrosting uses electromagnetic energy to generate heat directly inside frozen food. A high-frequency alternating field makes water molecules within the product vibrate, producing gentle internal warming that thaws or tempers large blocks in minutes rather than hours or days, without cooking the surface.

How long does RF defrosting take?

RF defrosting typically reduces thawing and tempering times from one to three days down to a matter of minutes. Exact times depend on product type, block size and target temperature, but the process is continuous and predictable, which makes production planning far simpler.

Does RF defrosting damage the product?

No. Because RF heats the whole block evenly rather than transferring heat slowly from the surface inwards, there are no hot edges or frozen centres. Products retain their texture, colour and structure, and there is no surface cooking or case hardening.

How much drip loss does RF defrosting cause?

Drip loss is substantially lower than with conventional thawing. Rapid, uniform heating minimises the temperature difference between the outside and core of the block, so products retain far more of their original weight, directly protecting yield and profitability.

Is RF defrosting hygienic?

Yes. RF defrosting is a clean, contact-free process that avoids the prolonged warm, moist conditions of traditional thawing rooms where bacteria multiply. The rapid, controlled heating keeps product within safe temperature ranges throughout.

What products can be defrosted with RF?

RF systems handle meat, poultry, fish, seafood, fruit, vegetables, ready meals and other frozen products. They suit solid blocks, cartons and IQF products, and are commonly used ahead of slicing, dicing, mincing, forming, cooking or further processing.

How much space does an RF defroster need?

Far less than a conventional thawing room. RF systems are compact in-line units that replace large refrigerated thawing areas, recovering valuable factory floor space. Multiple modules can be combined as production grows.

Who supplies RF defrosting equipment in the UK and Ireland?

Global Food Technology is the UK and Ireland supplier of Stalam industrial radio-frequency thawing and tempering equipment, providing sales, application advice, installation and ongoing support.

Ready to defrost smarter?

See the full specification, models and brochure for the Stalam COLDWAVE+ RF defroster.

View the Stalam COLDWAVE+ defroster

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