Blast Chillers & Shock Freezers for the Catering Industry: The Guide
A blast chiller (shock freezer) lowers the core temperature of cooked food in the shortest possible time – and is thus much more than a fast refrigerator: It is HACCP-relevant, improves quality, and reduces food waste. This guide explains the difference between blast chilling and shock freezing, why the cooling curve is crucial, and how to choose the right GN capacity.
Blast Chilling or Shock Freezing – the Difference
Both methods pass through the critical temperature zone particularly quickly. The difference lies in the target temperature – modern devices can do both.
| Method | Temperature Range | Time | Purpose |
|---|---|---|---|
| Blast Chilling | +90 °C → +3 °C | approx. 90 min | Fresh keeping, pre-production |
| Shock Freezing | +90 °C → -18 °C | approx. 240 min | Freezing without quality loss |
Why a Blast Chiller? HACCP & Quality
Between +65 °C and +10 °C germs multiply the most. A normal refrigerator takes hours to pass hot food through this zone – a blast chiller does it in minutes. This brings several advantages:
- HACCP-compliant: fast, documentable passing of the critical zone
- Longer shelf life: cooled food remains fresh and usable for several days
- Pre-production (Mise en place): precook, cool, portion – eases service pressure
- Less waste: small ice crystals during freezing protect cell structure, hardly any weight or quality loss
The Right Size (GN Capacity)
Blast chillers are measured by the number of GN 1/1 shelves. Plan according to your largest production run – better to choose one size bigger than constantly running multiple batches.
| Device | Capacity | Ideal for |
|---|---|---|
| SF 3 | 3 × GN 1/1 | Café, small kitchen, entry level |
| SF 5 | 5 × GN 1/1 | Restaurant, medium utilization |
| SF 8 | 8 × GN 1/1 | Canteen, high utilization, catering |
What to Look for When Buying
- Core temperature probe: a needle probe measures inside the product and ends the cycle temperature- instead of time-controlled
- Programs: "soft" for sensitive foods, "hard" for dense/large pieces
- Defrost function & hygiene: rounded inner corners and removable guides facilitate cleaning
- GN standard: compatibility with your existing GN containers and trays
- Installation: plan sufficient ventilation of the refrigeration unit
Frequently Asked Questions
What is the difference between a blast chiller and a shock freezer?
Blast chilling cools food to +3 °C (fresh keeping), shock freezing to -18 °C (freezing). Most devices – like the KBS-SF series – can do both.
How fast does cooling have to be?
The HACCP guideline is: from +90 °C to +3 °C in a maximum of 90 minutes to quickly pass the germ-critical zone.
Can I freeze with it as well?
Yes. Shock freezing creates only small ice crystals through fast freezing – the cell structure remains intact, and thawing results are much better than with slow freezing.
Why not just use a normal refrigerator?
A refrigerator is intended for holding cold goods, not cooling hot food. It would be too slow, goods stay too long in the bacteria zone, and quality suffers.
Blast Chillers at Gastro-Nik
- KBS SF 3 Blast Chiller / Shock Freezer – 3 × GN 1/1, entry level
- KBS SF 5 Blast Chiller / Shock Freezer – 5 × GN 1/1, restaurant
- KBS SF 8 Blast Chiller / Shock Freezer – 8 × GN 1/1, high performance
- KBS SF 5 Pro Blast Chiller / Shock Freezer – 5 × GN 1/1, extended programs
Which blast chiller suits your kitchen?
We advise you on capacity, programs, and HACCP documentation.
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Last updated on 2 September 2026.