Defrost in minutes,
not days
Radio frequency defrosting tempers frozen food from the inside out — no drip loss, no bacterial growth, no quality damage. Here's how it works, and why food processors are switching to it.
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.
How RF defrosting works
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.
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.
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.
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.
The benefits
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.
What can be defrosted?
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.
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.
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.
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 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 kW | Air | 0.6 m | 150–200 kg/h | 250–300 kg/h |
| 20 kW | Air | 1.4 m | 400–600 kg/h | 800–1000 kg/h |
| 40 kW | Air or water | 1.4 m | 800–1200 kg/h | 1500–2000 kg/h |
| 85 kW | Water | 1.8 m | 1500–2000 kg/h | 3000–4000 kg/h |
| 105 kW | Water | 1.8 m | 1500–3000 kg/h | 3000–5000 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.
Ready to defrost smarter?
See the full specification, models and brochure for the Stalam COLDWAVE+ RF defroster.
View the Stalam COLDWAVE+ defroster