The world's only vegetable that can't be frozen or canned

When it comes to purchasing vegetables, many of us often opt for frozen varieties, especially when we know we won't be able to consume them all. This can be a cost-effective method, as you can store them in the freezer and use them as needed.

Commonly frozen vegetables include carrots, peas, broccoli, cauliflower and festive trimmings. However, have you ever noticed that one vegetable is never available in supermarkets in a frozen, canned or cooked form?

Lettuce is always sold fresh, and this is due to its texture when frozen or canned.

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Comprising 95% water, lettuce does not freeze well. As explained by Chow Hound, a culinary site for food enthusiasts: "All that water inside the lettuce freezes into ice crystals, and because frozen water expands, those crystals break down the cell walls and overall integrity of the lettuce. This breakdown is why it becomes mushy when you thaw it: All of the "skin" of the vegetable has been ruined."

The high water content also explains why lettuce is not sold in cans - the vegetable wilts easily. If it is canned, it's usually after steaming!

If you're looking to extend the shelf life of your lettuce while preserving its flavour, you might consider pureeing it and then freezing it for use in soups or cooked meals. Alternatively, if you wish to store whole lettuce, a food expert has shared a simple trick to keep salads fresher for longer.

Culinary expert and Live Simply founder Kristin Marr has highlighted lettuce as one of the most "notorious" vegetables for going off too soon, attributing its rapid spoilage to its fragility and particular humidity requirements.

She shared her insights: "Greens need some moisture, but too much moisture is the enemy and will cause the greens to rot prematurely. This is why you don't want to wash delicate greens in advance, only when you need them."

Another factor affecting lettuce longevity is air circulation; excessive damp can build up in the tight confines of plastic wrapping, while the fridge's arid conditions may lead to wilting.

Marr advises an easy preservation method: detach individual lettuce leaves, arrange them in a ziplock bag with paper towels, seal, and refrigerate.