Blast Chillers & Shock Freezers for Catering: The Guide
A blast chiller (shock freezer) lowers the core temperature of cooked food in the shortest time – making it far 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 processes pass through the critical temperature zone very quickly. The difference lies in the target value – modern devices can do both.
| Process | Temperature Profile | 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 most rapidly. A normal refrigerator takes hours to pass hot food through this zone – a blast chiller does it in minutes. This brings several benefits:
- 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): precooking, cooling, portioning – reduces pressure on service
- Less waste: small ice crystals during freezing protect the 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 batch – better to choose a slightly larger size 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 volume |
| SF 8 | 8 × GN 1/1 | Canteen, high volume, catering |
What to Look for When Buying
- Core temperature probe: a needle probe measures inside the product and ends the cycle temperature-controlled instead of time-controlled
- Programs: “soft" for delicate foods, “hard" for dense/large pieces
- Defrost automatic & hygiene: rounded inner corners and removable guides make cleaning easier
- GN standard: compatibility with your existing GN containers and trays
- Installation: plan sufficient ventilation for 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 quickly must cooling be done?
The HACCP guideline is: from +90 °C to +3 °C within a maximum of 90 minutes, so the germ-critical zone is passed quickly.
Can I also freeze with it?
Yes. Shock freezing produces only small ice crystals due to rapid freezing – the cell structure remains intact, and the thawed result is significantly better than with slow freezing.
Why not just use a normal refrigerator?
A refrigerator is intended to store cold goods, not to cool hot food. It is too slow, the food stays too long in the bacteria zone, and the 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.
Last updated on 11 July 2026.