Anyone buying avocado in shops told 'eliminate the risk' by following 1 rule

are one of the most versatile and nutritious you can buy. Packed with fibre, healthy fats, and key nutrients, they're perfect in everything from and to toast and .

But while they might be delicious and healthy, picking the perfect can be a real challenge. Luckily, have now shared a simple tip that could save shoppers money, and help avoid disappointment.

According to , the number one rule when buying avocados is simple: never purchase ripe avocados.

The site explained: "Regardless of which variety you choose, the one inviolable rule of purchasing avocados is to only buy them totally unripe. You want them greenish and rock hard. That enables you to eliminate the risk of bruising."

That's because ripe or partially ripe avocados are far more likely to have already been squeezed, handled or dropped, something that leads to bruising inside the fruit.

Even small bruises can lead to brown rot spreading as the avocado ripens.

"People tend to squeeze avocados at the market to test ripeness, and that's all it takes to cause bruising," the Vegan.com guide added.

By buying only hard, green avocados, shoppers can avoid this. And while it means a short wait before eating, the result is often a far better piece of fruit.

To ripen avocados at home, experts recommend storing them at room temperature, ideally in a fruit bowl.

If you want one to ripen more quickly, you can place it in a paper bag with the top rolled shut. This usually speeds up ripening by a day.

The key is checking them regularly, at least twice a day, because there's only a short window when an avocado is perfectly ripe.

The guide added: "Figure it takes about a day for a not-quite-ripe avocado to perfectly ripen.

"Then less than another day until it starts going downhill. If you wait too long, it'll often have developed disgusting hairlike brown fibres running through the fruit."

To test ripeness, squeeze gently and look for softness. But experts warn against opening it too early.

If the inside is still stuck to the pit or won't mash properly, it's not ready, and the whole fruit may be wasted.