How IQF freezing works
The science and engineering that turn loose pieces of food into free-flowing, individually frozen product.
The principle of individual quick freezing
IQF freezes each piece separately in a fast-moving stream of sub-zero air instead of freezing a whole block. Because every piece is surrounded by cold air, it freezes quickly from the surface inward, forming small ice crystals and staying free-flowing for easy weighing, packing and portioning.
What IQF does better
Individual, free-flowing pieces
Pieces stay separate after freezing, so they are easy to weigh, portion and pack without defrosting or breaking a block.
Smaller ice crystals
Fast freezing produces many small crystals instead of a few large ones, protecting cell structure, texture and juiciness.
Lower dehydration loss
A rapid surface freeze seals in moisture, keeping dehydration low and improving yield.
Better colour and flavour
Short freezing times preserve natural colour, aroma and nutrients better than slow block freezing.
The three-stage freezing process
Pre-cool
Product is cooled rapidly toward freezing point to remove sensible heat without freezing.
Surface freeze
A high-velocity bed freezes the surface to around 0 °C, preventing pieces from sticking together.
Deep freeze
Dwell time completes the freeze to the core, reaching a stable -18 °C outlet temperature.
Key engineering factors
| Air velocity (fluidized bed) | Up to ~30 m/s to suspend small pieces |
|---|---|
| Air velocity (tunnel / spiral) | 3 – 8 m/s for larger or packed products |
| Working temperature | -35 to -40 °C |
| Typical dehydration loss | Below 2% on a well-tuned IQF line |
| Outlet temperature | -18 °C |
| Drip loss after thawing | 3 – 8% (IQF) vs 10 – 20% (block frozen) |
Figures are indicative and depend on product type, piece size, inlet temperature and line tuning. We confirm them for your product during engineering and commissioning.
Freeze your product the right way
Send us your product and capacity and our engineers will define the freezing time, airflow and line layout.
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