Chilled shipping for fish and seafood
Short answer: ship fresh fish at 0 to 2 °C in a moisture-resistant EPS box with crushed ice or gel packs (at least 50% of the fish weight in cooling), always with a leak-proof inner bag and an absorbent pad on the bottom. Frozen fish requires -18 °C or lower; smoked fish 2 to 4 °C.
Fresh fish is exceptionally sensitive to temperature fluctuations. Under poor cooling conditions, bacteria develop quickly, which affect freshness and cause food safety risks. For the fish processing industry, the right packaging is important.
Temperature requirements
- Fresh fish: 0 to 2 °C (on melting ice)
- Smoked fish: 2 to 4 °C
- Frozen fish: -18 °C or lower
- Seafood (fresh): 0 to 2 °C
The right packaging
For fish shipments we recommend:
- EPS boxes: a good combination of insulation and moisture resistance. EPS does not absorb moisture or odour. View our EPS boxes.
- Ice or gel packs: for fresh fish, crushed ice directly on the fish
- Absorbent pads: important for catching meltwater and leaking fish juices
- Leak-proof inner bag: prevents contamination on the outside
- Film around the fish: choose film that is intended for contact with foodstuffs and ask your supplier for the specification
For commercial fish shippers
Online fishmongers, restaurants that distribute fresh fish and fish wholesalers often work with Cooled Solutions because of:
- Fixed price agreements for volumes
- Fast delivery from stock
- Custom packaging for specific fish species
- Combinations on pallets (mix of cooler boxes + loose components)
Important points of attention
- Always put fish in vacuum or leak-proof packaging before it goes into the EPS box
- Sufficient ice/cooling elements: at least 50% of the fish weight
- ALWAYS use an absorbent pad, otherwise you will get damaged shipments
- Label clearly 'Fish, short shelf life' or 'Perishable'
- Plan shipping preferably Tuesday to Thursday
Crushed ice or gel packs?
Both work, but they behave differently. Crushed ice lies directly against the fish and keeps the product around the melting point. It does melt, however, and so produces water. The box has to be able to withstand that. Gel packs stay closed and do not release meltwater onto the fish, but they make less good contact with the product. For flat products such as fillets, ice pack sheets are a handy variant, because they spread the cold over the surface. Choose on the basis of your product, the journey time and the way in which the recipient unpacks the box.
Packing step by step
- Start cold. The fish must be at the right temperature before it goes into the box. A box with coolant does not cool warm fish back down.
- Place an absorbent pad on the bottom and, where relevant, a leak-proof inner bag as a second barrier.
- Pack the fish in vacuum or in a closed bag, so that fish juice does not get loose in the box.
- Place the coolant around and above the fish. Cold air sinks, so cooling on top works best.
- Fill empty space. Still air warms up faster than a full box.
- Close with the matching lid and tape the box shut. As standard we supply EPS boxes with a matching lid. Loose lids are available on request.
Why things go wrong
- Too little cooling: the 50% rule is a lower limit. In warm weather or on long routes, more is needed.
- Box stands still too long: waiting time in a warm depot or vehicle costs more than the journey itself.
- Leakage: fish juice can contaminate the box and the rest of the shipment. Therefore use an inner bag and an absorbent pad.
- Wrong size: a box that is too large with a lot of air warms up faster. Read choosing the right box size.
Checklist for the fish shipment
- Does the fish have the right starting temperature?
- Is the fish packed in vacuum or leak-proof?
- Is there an absorbent pad on the bottom?
- Is there enough cooling for the journey time?
- Is the box properly closed and labelled as perishable?
- Does the recipient know when the shipment will arrive?
Measuring pays off
On a new route, place a data logger in the box and look at the temperature curve after arrival. The actual holding time depends on outside temperature, filling and the amount of cooling. You will find more background in our article shipping fish chilled: what it comes down to.
Frequently asked questions
May fish lie directly on gel packs?
It can, but watch for freezing of the surface if you want to keep fresh fish at 0 to 2 °C. A layer of film or an inner bag in between is a safe choice.
Can I reuse an EPS box for fish?
We advise against it, because odour and fish juice can remain in the box. For fresh fish, preferably use a clean box.
Is EPS suitable for foodstuffs?
EPS is widely used for packaging and chilled shipping of foodstuffs and does not absorb moisture or odour. We are happy to answer questions about conformity for your application.
Cooled Solutions has supplied customers in the fish processing industry for years. For advice on your specific situation: contact our sales support team.
Order directly
Need the right packaging straight away? View our EPS boxes, cooling elements, absorbent pads and cold chain packaging for the food sector.
