Shipping Fish Chilled: What Really Matters

Fish is the most demanding of all perishable products. Every degree counts immediately, and meltwater makes the problem bigger instead of smaller. Here's how to approach it.

Start with fish that's already at temperature

A box insulates, but doesn't cool. Fish that has already warmed up won't come back to temperature, no matter how much coolant you add. Pack in the cooled area, not on the loading dock.

Choose a box with drain holes

Fish releases meltwater. Without drain holes, that moisture stays in the box and affects quality. For whole fish and fillets, choose a version with drain holes. Only for vacuum-packed products, or when the recipient must not receive any moisture, choose a sealed version.

Coolants on top

Cold sinks. Place cooling packs or cooling sheets on top of the product, not underneath. For flat products such as fillets, sheets work better than thick packs: they lie flat across the entire surface.

Wall thickness based on transit duration

For a same-day trip, thin-walled is sufficient. If the shipment travels overnight or it's warm weather, choose thick-walled. Plan for the longest possible transit time, not the average.

Fill the box

A full box holds temperature considerably longer than a half-full one. Choose a smaller size that gets filled rather than a large one with air inside.

Air freight

If the fish goes into the air on a pallet, a thermal cover goes over it. The vulnerable moment isn't the flight itself but the hours on the platform.

In practice

The salmon box, a long narrow box, is specially made for whole fillets. That fit isn't a detail: less dead space means less warming and less shifting during transport.