2024 marks 100 years since Clarence “Captain” Birdseye, made a discovery that was to revolutionise the food industry – the invention of a commercially-viable method for quick freezing seafood. Since then, frozen seafood has become a household staple and Birds Eye a household brand.

Many consumers, especially those who grew up in urban areas of northern Europe, early seafood experiences will be closely linked to the figure of Captain Birdseye, also known as Captain Iglo, – the jovial seafarer whose familiar face beams out from the packaging of child-friendly seafood staples such as fish fingers. But only a small proportion will appreciate that Birdseye, while not a real captain, was a real man.

Born in New York City in 1886, the sixth of nine children, Birdseye is widely considered the founder of the modern frozen food industry – having invented a series of cooling techniques, which culminated in the double belt freezer, which he unveiled in 1925.

This ingenious method, which is still widely used today, consists of two parallel conveyor belts – one containing delicate items, such as fish fillets, while the other runs in the opposite direction. As the belts move, the items are subjected to a blast of cold air. This allows for quick freezing while maintaining the integrity of individual items and also offers flexibility in processing seafood of different shapes and sizes.

The technology was sufficiently impressive to attract the attention of Goldman Sachs, which bought Birdseye’s fledgling company and patents for $22 million in 1929 and, following successful trials with US consumers, by the mid-1930s frozen foods were increasingly mainstream in America, and soon spread across the world.

The importance of frozen seafood

Although freezing technologies have since become more sophisticated, Birdseye helped to make seafood available to the masses, as the frozen version brought a number of significant advantages to the entire supply chain.

Thanks to Birdseye, numerous forms of seafood are available year-round, globally, and can be easily stored for longer periods, making it convenient for consumers to purchase and use when needed. As less tends to be spoiled and wasted, frozen seafood can also be both more environmentally friendly and affordable than its fresh equivalents.

A range of freezing methods

As well as belt freezing, there are three main methods currently used for freezing seafood.

Blast freezing involves rapidly lowering the temperature to -18°C or below within a short period, usually by subjecting it to very cold air or direct contact with a refrigerant. This method ensures quick freezing, which helps to maintain the freshness, texture and flavour.

Plate freezing involves placing the item between metal plates cooled to freezing temperatures. This method is effective for preserving the quality of delicate seafood varieties by minimising damage to their cellular structure.

Cryogenic freezing involves immersing seafood in a bath of liquid nitrogen or carbon dioxide at extremely low temperatures. The rapid freezing process results in the formation of small ice crystals, which helps preserve the texture and integrity of the food.

Defrosting seafood – dos and don’ts

While freezing has many advantages, as covered above, most forms of frozen seafood – other than convenience products such as breaded fish fillets and fish fingers – need to be defrosted before they can be cooked.

Unlike the rest of the steps in the supply chain, this is generally done by the consumer, so here are a couple of useful household tips.

For quick thawing, place the seafood in a sealed plastic bag and submerge it in cold water. Change the water every 30 minutes to ensure it stays cold. This method works well for smaller items like shrimp or fillets and typically takes around 1-2 hours.

Alternatively, you can thaw seafood in the refrigerator overnight – a method that preserves the texture and flavour, but requires good planning.

Avoid defrosting seafood at room temperature, as this can promote bacterial growth and spoilage. Similarly, avoid using hot water or the microwave for thawing as they can unevenly cook the seafood or cause it to become rubbery.

Never refreeze seafood that has been previously frozen unless it has been cooked first.

Birdseye’s legacy

Clarence Birdseye died in 1956 at the age of 69, but since then the frozen seafood sector has gone from strength to strength – in the UK, for example, around a quarter of the seafood in retail outlets is sold frozen – and frozen seafood is gaining credibility as freezing techniques improve.

Not only is it increasingly seen as a means to reduce waste and preserve freshness, but it is also gaining strong sustainability credentials – frozen seafood can be transported long distances by containership, for example, while many fresh products are flown long distances around the world, racking up much larger carbon footprints.

While the world has changed hugely since Clarence Birdseye’s great inventions, as have the advantages of frozen seafood, his work should still be celebrated today.