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Are Kiwis Supposed to Be Sour?

The bright green (sometimes gold) kiwifruit is one of the fuzziest fruits in the grocery store. When you hold one in your hand, you’ll notice the outer skin feels a little frizzy, but the inside is soft, juicy, and an enticing shade of green.

Kiwifruit was once known as the Chinese gooseberry. It became popular in Western culture in the early 1970s after New Zealand kiwi exporters changed this fuzzy fruit's name from Chinese gooseberry to kiwifruit. It became an instant sensation!

What you might not realize is that kiwifruit is packed with nutrition, with more vitamin C than an orange.

The Sweet and Sour Story of the Kiwi

Are kiwis supposed to be sour? Some people gravitate toward fruit with a bright green interior because they enjoy its sweet taste. But kiwis can also be sour. How sweet or sour a kiwifruit is depends on how mature it is.

Younger, unripe kiwifruit have a distinctively sour and slightly astringent taste. Some people even describe the taste of unripe kiwifruit as bitter. But if you bite into a mature kiwifruit, it's more likely to taste sweet.

What's the Deal with Underripe Kiwifruit?

If a kiwi is underripe when you bite into it, it will taste sour. At the other end of the maturity spectrum, it may also have an unpleasant taste if it’s too ripe. This doesn’t mean it's spoiled; rather, it's just part of the natural ripening process and should not deter you from enjoying the fruit's many benefits.

Kiwis are usually sweetest when they're riper but not so ripe that they’re mushy. You can pick kiwis when they’re still unripe and immature and they'll continue to ripen after you take them home. Once it no longer feels hard and has a little “give” when you squeeze it, it’s ready to enjoy. You can eat it while it’s still hard and immature, but it will likely be sour.

A ripe kiwifruit should have a sweet aroma, like that of a pineapple. If it smells like vinegar or is mushy, it’s probably past its prime and won’t give you a satisfying experience when you bite into it. It will likely be mushy at this stage too. If you squeeze it and it feels like mush, it’s too ripe.

If you happen to purchase an overripe kiwifruit, there’s still hope. You can use a mushy one to make smoothies or jams. Kiwis ripen quickly once you cut them open. So, store your kiwis at room temperature on the countertop until they are ready to eat so that their flavor develops fully.

Other Ways to Enjoy Kiwifruit

  • Make a fruit salsa using kiwi, pineapple, and mangoes.
  • Bake kiwi into muffins or cakes for a sweet treat.
  • Use kiwi slices as a garnish on salads and other dishes
  • Add sliced kiwi to green smoothies or fruit salads.
  • Use fresh kiwis to make homemade jam or preserves.
  • Use juice from canned kiwis as an ingredient for lemonade.
  • Puree some fresh kiwis with yogurt or milk to make a smoothie base; add honey if needed for sweetness.
  • Kiwi slices look beautiful on top of cakes, pies, puddings, and ice cream sundaes.
  • Use kiwi juice as a replacement for vinegar. When you're making salad dressings or marinades, substitute half of the vinegar with kiwi juice instead. It will add some sweetness to your dish and give it an extra kick of vitamin C.

As you can see there are lots of ways to use kiwifruit and get a healthy dose of vitamin C and potassium too. The fruit is also a good source of fiber and antioxidants.

Be aware that some people experience mouth itching when they eat kiwi and certain other types of fruits. This is likely a condition called oral allergy syndrome and you should avoid eating kiwi in the future.

The Bottom Line

Are kiwis supposed to be sour? You may get a sour-tasting kiwi occasionally, but don't assume that's how they all are. Kiwis are like people: they aren't all alike. Some kiwis are sourer than others. The best way to avoid the sour ones is to choose ones that have the right degree of ripeness, are not too immature, and are not too ripe.

There are over 40 types of kiwis and each one has its own unique taste—so don't be afraid to try something new and bite into a kiwifruit!


"History of the Kiwi Fruit."

Ma T, Lan T, Geng T, Ju Y, Cheng G, Que Z, Gao G, Fang Y, Sun X. Nutritional properties and biological activities of kiwifruit (Actinidia) and kiwifruit products under simulated gastrointestinal in vitro digestion. Food Nutr Res. 2019 Apr 8;63. doi: 10.29219/fnr.v63.1674. PMID: 31007652; PMCID: PMC6458959.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.