Dietitians Share How Banana Ripeness Affects Flavor, Sugar, and Gut Health

My husband and I agree on a lot of things, but determining when a banana is ripe is unfortunately not one of them. I like to wait until the skin of the banana is speckled with brown spots, which is when I know it has gone from starchy to sweet. At this point, my husband won’t touch it; he prefers bright-yellow bananas that still have a tinge of green on their skin, and definitely no spots.

So, spots or no spots? To settle the debate, I asked Anar Allidina, M.P.H., R.D., C.D.E., Stephanie Crabtree, M.S., R.D. and Stephanie Militano, M.S., R.D., C.S.S.D. Here’s what they told me—plus, everything you need to know about buying and storing bananas.

When Is a Banana Ripe?

First things first—how do you know when a banana is ripe? Our experts agreed that a banana is ripe when its peel is yellow, it feels slightly soft to the touch, and it has a sweet smell. “A perfectly ripe banana is bright yellow, soft to the touch, and usually smells sweet,” Crabtree says.

Should You Pick the Bananas with Spots?

When shopping at the grocery store, should you choose bananas that are green, bright yellow, or speckled? In short, it depends on how and when you want to eat them.

• Green bananas last the longest and are best if you plan to ripen them for a few days before using
• Firm, bright yellow bananas are ripe and can be eaten right away
• Yellow bananas with spots are even more ripe; they're sweeter and can be eaten raw or baked

“If you’re eating bananas right away, choose bananas that are yellow. These are ripe, sweet, and soft,” Allidina says. “If eating in a few days, look for bananas that are mostly yellow with a hint of green at the stem. If storing longer, look for green bananas, which will ripen over several days at room temperature."

How Does a Banana Change as it Ripens?

As you probably know, bananas will change in color as they ripen, from green to yellow to yellow with brown spots to, eventually, brown. And as the color of a banana changes, so does its flavor, texture, and nutrition profile.

Flavor

Ever wonder why your favorite banana bread recipe calls for brown bananas? That’s because very ripe bananas—which are speckled with brown spots or even completely brown—are naturally sweeter than their green or yellow counterparts. “As bananas ripen, their starches (complex carbohydrates) turn into natural sugars so the browner the banana, the sweeter the bite!” Militano says. “Green bananas are more fibrous and less sweet, while ripe bananas bring extra sweetness.”

Texture

Overripe bananas are also ideal for banana bread and other baking projects because they’re softer than less ripe bananas. As a banana ripens, its texture changes from firm and starchy to soft and creamy.

Nutrition Profile

There’s a scientific reason a banana with spots is sweeter than a yellow or green one. Green bananas are high in resistant starch, which converts into simple sugars (glucose, fructose, and sucrose) as they ripen. Generally speaking, green bananas are higher in fiber and brown bananas are higher in sugar.

“Green bananas contain more resistant starch and less sugar, which acts like fiber and digests slowly,” says Allidina, who notes that this makes them great for gut health and better blood sugar control. “Yellow bananas offer a balance of sugar and starch, are easy to digest, and have slightly higher antioxidant levels. Spotted or brown bananas are the sweetest, with the most sugar and softest texture, and also contain the highest levels of antioxidants—perfect for baking or blending into smoothies.”

While spotted bananas have higher sugar content and a higher glycemic index, that doesn’t necessarily make them less nutritious than firm green or yellow ones. “While they have more sugar, spotted bananas can contain higher levels of antioxidants,” Crabtree says. “Each stage offers different benefits depending on your health needs.”

Signs of Spoilage in Bananas

While some brown on a banana is perfectly fine, there is a point of no return. If your bananas have any of these signs of spoilage, it’s time to toss them:

• A strong fermented or sour smell
• Liquid leaking from the peel
• Large dark brown or black patches
• Visible mold on the skin or peel
• Soft, mushy, or slimy texture

How to Store Bananas

Whether you prefer your bananas with or without spots, you’ll want to follow a few key storage guidelines to prevent them from spoiling. Store bananas at room temperature out of direct sunlight and keep them away from other fruits, as they release ethylene gas. Some tricks to slow down ripening and prevent bruising include separating bananas from the bunch, hanging them from a hook, and wrapping their stems in plastic wrap to prevent the release of ethylene gas.

If you don’t plan to use your bananas right away, you can also peel them and store them in the freezer to throw in a smoothie or bake into banana bread later.

How to Use Overripe Bananas

If you can’t stomach the idea of eating a raw banana once its skin turns speckled, you still don’t have to toss it. Overripe bananas are ideal for baking, mixing into batter, and freezing for smoothies and other frozen treats. Try using your overripe bananas in one of these recipes:

• Banana bread 
• Muffins
• Cookies
• Smoothies
• Ice cream
• Pancakes
• Waffles