Freezing vegetables: What you need to know

Frozen vegetables are the ultimate kitchen convenience – why go through the hard yards of chopping vegetables when you can just open your freezer and have them prepared in advance?

But have you ever wondered about the story behind that convenience? It’s far more than just throwing some food in a freezer. There is a refined process for freezing vegetables in order to maintain their freshness, quality and nutritional value.

Where did it all begin?

The concept of flash-freezing produce came from Clarence Birdseye (do you recognise the name?). He lived in the arctic region of Canada and became fascinated with the sub-zero Arctic air, which froze freshly caught fish in an instant.

He noticed that the fish retained its taste and texture when cooked post-freezing. This led to a series of experiments, where Birdseye froze all kinds of produce including meats, fruits and vegetables. These successful experiments in freezing and cooking led Birdseye to believe he was onto an idea of commercial value (he most certainly was) and in 1917 he left Canada with his family and moved to New York.

It was in New York that Birdseye invented his mechanical freezing device. From the day his family moved to America, he devoted himself to the invention and was granted a patent for it in 1923. After the patent came his business – the Birdseye Frozen Fish Company.

It wasn’t initially successful, but it did start off what would eventually become a huge part of the food industry.

How does it work today?

Freezing food has come a long way in terms of technology since 1923 – it’s now a seven-step process, automated by many different pieces of machinery.

Cultivation: Vegetables are grown as per the standards of the food processor in question. These standards have a great deal of research behind them in order to determine which peas freeze the best and how they should be grown to be of top quality, for example.

Harvesting: This can either be by hand or using a machine.

Washing: To remove any dirt, the veggies are washed with an automatic system involving conveyor belts and water sprayers. In the case of vegetables that are chopped up before packaging, this is done post-wash in order for the individual pieces to become properly blanched in the next phase of the process.

Blanching: Blanching is another word for cleaning. The vegetables are briefly put in a vat of boiling water to kill bacteria and also deactivate the enzyme that causes the produce to go bad. They aren’t in there long enough to be cooked.

Inspection: The vegetables are passed by inspectors who sort the good veggies from the bad ones, and also take out anything that shouldn’t be in there (such as rocks that may have made it in from the farm).

Freezing & Packing: The order of freezing and packing varies between processing plants, but they still come out the same at the end. In some cases the vegetables will pass through a tunnel which blasts them with ice-cold air, freezing them prior to packaging. If the veggies are packaged before freezing, the individual packs are loaded onto large trays, and then frozen by cold plates above and below.

Distributing: This is the final phase of getting frozen vegetables to the consumer. Special freight methods such as refrigerated trucks must be used to keep the vegetables frozen as they make their way to supermarkets where they are available for purchase.

So all you need to do is go to your local shop and buy your favourite variety. Out of all the brands that featured in our latest ratings, ALDI’s private label range proved to be the most popular. You can view the full customer satisfaction ratings here.

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