Supermarket shoppers buying avocados have been hit with a 'five-day warning'.

Unlike most fruits like bananas, apples or pears, it is very difficult to tell the ripeness of an avocado just from the way it looks on the outisde - so shoppers are advised to apply a strict five day rule to their purchases. Experts at Fresh Avocados - Love One Today warn that if you are buying an avocado for a specific occasion or event, then you should always buy it exactly five days in advance. The fruit also needs to be green in colour and feel firm to the touch.

The experts say it takes around five days on average for firm or green fruit to ripen at room temperature, meaning buying five days in advance should guarantee your avocados will be fully ripe in time for your event.

The nutrition website explains: “Unripe, firm green avocados can be purchased four to five days ahead of an event. Ripe fresh avocados that yield to gentle pressure should be eaten within a day or two. For events that are four to five days out, purchase firm avocados instead. Unripe, firm or green fruit can take four to five days to ripen at room temperature, perfect for celebrations that are a few days out. 

“Just be careful to watch the fruit to make sure the temperature in your kitchen does not cause them to ripen too quickly. If they begin to yield to gentle pressure, place them in the refrigerator to slow the ripening process.”

Fresh avocados that are almost ripe will feel less firm, be darker in colour and won’t quite yield to gentle pressure. When avocados are at this stage it is advised that you wait one to two days to allow the fruit to fully ripen, otherwise the flesh inside will be hard and difficult to mash.

If avocados are almost black in colour with just a hint of green, and yield to pressure, this is when they are at their ripest and should be eaten right away.

The colour of the fruit can vary depending on the variety you choose. For example, Fuerte, Ettinger, Reed, and Sharwill avocados stay green when ripe so it’s best to go by firmness, as well as colour, to determine if the fruit is ready to eat.

If an avocado feels mushy to the touch and has deep indentations, with darker yellow or brown coloured flesh, then it is overripe and best avoided.