“Some fruits (like these nectarines) really do ripen faster in a paper bag. Lori Sparkia/Shutterstock
Whether or not you are a fruit aficionado, you’ve probably heard that you should keep unripened fruit in a brown paper bag to speed up the ripening process. But do paper bags really help fruit ripen? And if so, how?
The answer depends on the fruit.
It’s Not the Color of the Bag — It’s the Material
It’s true, some fruits pass gas — ethylene gas to be exact. It’s released by the growing tips of roots, flowers, damaged tissue (a.k.a. bruising) and during ripening. This hormone is responsible for several plant effects, one of which is ripening. When fruit ripens, ethylene converts the starch in the fruit’s flesh into sugar, creating a sweeter, tastier fruit.
When an ethylene gas-producing fruit is placed in a closed environment like a paper bag, the gas begins to accumulate around it, essentially giving it a hearty dose of ripening elixir. And thus, the fruit ripens faster. You can even add a ripened piece of fruit to an unripe one for an additional ethylene boost.
Plastic bags can trap ethylene gas as well, but they are not breathable. So, they also trap moisture which can cause the fruit to rot before it ripens. Paper bags — whether they are brown or white or any color in between — are ideal because they promote airflow. But they aren’t the only ideal ripening container. You can also store ripening fruit in other breathable materials such as cotton cloth or even bowls of rice (though this option isn’t ideal for softer-skin fruits like peaches).
Which Fruits Ripen After Picking?
There are two classifications of fruit in the ripening realm — climacteric and non-climacteric. In short, climacteric fruits produce ethylene gas and continue to ripen after they’ve been plucked while non-climacteric fruits do not and thus should only be picked when fully ripe.
Climacteric fruits include:
- apricots
- avocadoes
- bananas
- kiwis
- mangoes
- nectarines
- peaches
- pears
- plums
- tomatoes
Non-climacteric fruits include:
- apples
- coconuts
- cherries
- grapefruit
- grapes
- oranges
- pineapples
- strawberries
- tangerines
- watermelons
The optimal time to eat a fruit, of course, is when it’s ripe because it’s at its peak flavor and texture profile. But climacteric fruits are picked and sent to the supermarket before they are ripe. That’s because many soften as they ripen, which makes them susceptible to bruising and rotting. Harvesting them when they are still firm and unripe helps minimize damage during shipment and extends shelf life. When you bring these home, let them ripen for a few days before eating.
Non-climacteric fruits, on the other hand, will not continue to ripen nor become sweeter once they are taken off the plant. Thus, they need to stay on the plant until they reach full ripeness and eaten shortly soon after.
Now That’s Good to Know
When you bring home climacteric fruits, be sure to put them in a breathable sack (like a paper bag), leave out at room temperature and only refrigerate after they ripen. Warmth stimulates the ripening process while cold inhibits it.
