Unripe kiwis ripen best at room temperature, stored between 59°F and 70°F, and you can speed the process significantly by placing them in a paper bag with an ethylene-producing fruit like an apple or banana. Most store-bought kiwis are rock-hard, but with the right storage approach, you can have perfectly ripe fruit in just a few days.
Why Kiwis Ripen After You Buy Them
Kiwifruit is a climacteric fruit, meaning it continues to ripen after being picked. The key player is ethylene, a natural gas that plants produce. Ethylene triggers the conversion of starch in the fruit’s flesh into sugar, which is what transforms a hard, tart kiwi into a soft, sweet one. At room temperature (around 68°F), kiwifruit softens at a surprisingly fast rate. The warmer the environment, the quicker the process. Below 45°F, ripening slows to a crawl, which is exactly why grocery stores and commercial distributors keep kiwis cold during shipping.
This means you have a simple lever to pull: temperature controls the speed, and ethylene controls the trigger.
The Paper Bag Method
The fastest way to ripen kiwis at home is to place them in a paper bag with a high-ethylene fruit. Apples and pears are the strongest ethylene producers among common household fruits, followed by bananas, avocados, peaches, and nectarines. One apple or banana in the bag alongside your kiwis is plenty.
Close the top of the bag loosely (a fold or two is fine) and leave it on the counter at room temperature. The bag traps the ethylene gas around the fruit, concentrating it and accelerating ripening. Paper is the right material here because it’s breathable. It lets moisture escape while still holding ethylene in. Plastic bags trap moisture alongside the gas, which can cause the fruit to rot before it ever ripens.
With a companion fruit in the bag, most kiwis will be noticeably softer within two to three days. Without the companion, expect the process to take closer to four to seven days depending on how firm they were to start.
Ripening on the Counter Without a Bag
If you’re not in a rush, you can simply leave kiwis on the counter at room temperature. They’ll ripen on their own, just more slowly. Keep them out of direct sunlight and away from heat sources like stovetops. This passive approach works well if you buy kiwis at different stages of firmness and want them to ripen in a staggered way so you don’t end up with six ripe kiwis at once.
One thing to watch: don’t leave kiwis sitting next to your fruit bowl if it’s full of apples or bananas, unless you want them ripening faster than expected. Ethylene from nearby fruit will do the job even without a bag.
How to Tell When a Kiwi Is Ripe
Gently press the kiwi with your thumb. A ripe kiwi yields slightly under light pressure, similar to a ripe peach or avocado. If it’s still hard with no give at all, it needs more time. If it feels mushy or the skin looks wrinkled and sunken, it’s past its prime.
Ripe kiwis also have a faintly sweet, fragrant smell near the stem end. Unripe kiwis have almost no aroma. The skin color doesn’t change much during ripening, so touch and smell are your most reliable indicators.
Storing Ripe Kiwis in the Refrigerator
Once your kiwis reach the ripeness you want, move them to the refrigerator immediately. Cold temperatures slow ethylene production and dramatically extend shelf life. Ripe kiwifruit will keep for five to ten days in the fridge. Very firm, unripe kiwis stored in the refrigerator can last up to a month, which is useful if you’ve bought in bulk and want to ripen them in batches.
Store ripe kiwis away from apples, bananas, pears, avocados, and tomatoes in your fridge. Even at cold temperatures, the ethylene from those fruits can push your kiwis past their peak. A separate crisper drawer or a loosely closed container works well. The ideal humidity for stored kiwis is high, around 90 to 95%, so a crisper drawer set to the high-humidity setting is the best spot. This prevents the skin from shriveling and drying out.
Freezing Kiwis for Long-Term Storage
If you have more ripe kiwis than you can eat within a week, freezing is a practical option. Peel the kiwis first, then slice them into rounds or chunks. Spread the pieces in a single layer on a parchment-lined baking sheet and freeze until solid, usually about two hours. Transfer the frozen pieces to a freezer bag, pressing out as much air as possible. This prevents the slices from clumping into a solid block.
Frozen kiwi works best in smoothies, sorbets, or as a topping for yogurt. The texture softens considerably after thawing, so eating a frozen-then-thawed slice on its own won’t give you the same experience as fresh fruit.
Quick Reference by Situation
- Need ripe kiwis in 2 to 3 days: Paper bag on the counter with an apple or banana, loosely closed.
- Need ripe kiwis in 4 to 7 days: Counter at room temperature, no bag.
- Want to delay ripening for weeks: Refrigerate unripe kiwis immediately. They’ll keep up to a month and ripen within a few days once you bring them back to room temperature.
- Already ripe, eating soon: Refrigerate and use within five to ten days. Keep away from ethylene-producing fruits.