When it comes to buying vegetables, many of us often choose frozen options, particularly when we know we won’t be able to eat them all before they go off.

This can be a cost-effective way of shopping, as you can keep them in the freezer and use them as and when you need them.

Commonly frozen veggies include carrots, peas, broccoli, cauliflower and festive trimmings. But 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. Made up of 95% water, lettuce doesn’t freeze well.

As explained by food site Chow Hound: “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 isn’t sold in cans – the vegetable wilts easily. If it is canned, it’s usually after being steamed.

Chowhound added: “But if you put a crisp raw cabbage directly in the freezer, it may come out soft and squishy with a generally unpleasant texture when you thaw it, and would not make for a good slaw or other dish that calls for crisp cabbage.

“But there’s some ambiguity around this question: Frozen raw cabbage may lose all of its crispness and become soft in texture, but it could still be suitable for dishes where it’ll be cooked, especially if it’s dishes with lots of liquid like soups and stews. This way, the softness of the thawed cabbage doesn’t really matter since the cooking process would soften it up either way.”

If you’re looking to make your lettuce last longer while keeping its taste, you might consider pureeing it and then freezing it for use in soups or cooked meals. Alternatively, if you want to store whole lettuce, a food expert has shared a simple trick to keep salads fresher for longer.

Live Simply’s culinary expert, Kristin Marr, has called out lettuce as one of the “notorious” veggies for going off quickly due to its delicate nature and specific need for humidity. She explained in a tip: “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.”

She also noted that lettuce’s shelf life can be influenced by air circulation — too much moisture gets trapped when it’s encased in plastic, and conversely, the fridge’s dry atmosphere might lead to dehydration and wilting.

For longer-lasting lettuce, Marr suggests a simple trick: separate the leaves, layer them with paper towels inside a ziplock bag, seal it up, and pop it in the fridge.