I bought rock-hard avocados for guacamole on a Tuesday and needed them ready by Wednesday. Four different times I tried the counter method and ended up either waiting a week or cutting into one that was somehow both hard and brown.

Then a produce manager told me about the paper bag trick, and I have not gone back.

How it works

Avocados ripen because of a gas called ethylene that the fruit gives off. Trap that gas in a bag and you speed the whole thing up dramatically.

• Put the avocado in a paper bag, not plastic
• Add a banana or an apple to the bag
• Fold the top closed and leave it on the counter
• Check after 24 hours

The banana is the secret weapon. Bananas are ethylene machines, and they will push a hard avocado to ripe in about a day instead of four.

The mistakes I made

Do not use a plastic bag. It traps moisture and the skin can get damp and moldy before the inside ripens. Paper lets the fruit breathe while still holding the gas.

And check it daily. The jump from “not ready” to “overripe mush” happens fast once it gets going. Give it a gentle squeeze near the stem. If it yields a little, it is ready to eat.