Why use brown bananas for baking?
I’m usually pretty particular about my bananas, preferring a slight green just at the stem for less sweetness and a firmer bite. But when it comes to baking, the browner the better. It may take some patience—the bananas I got to make these muffins took a full week and a half on the counter to reach the generous speckle stage—but it’s worth it.
Eat a green banana beside a fully yellow one and it’s hard to believe they’re even the same fruit. Bananas, along with avocados, pears, and tomatoes, store their energy in starches. Because these large molecules are just long, sometimes branched chains of glucose, breaking them down leads to a softer, sweeter fruit. As the banana ripens, that’s exactly what happens: an enzyme (the worker bee of cellular machinery) chops the starch into individual sugar molecules. Other enzymes control reactions that create flavor molecules and color change, giving us visual clues of when the fruit reaches its most delicious point.
Bananas show one of the highest conversions of any fruit, which is why the stage of ripening has such an impact. In green fruit, starch outnumbers sugar 25 to 1, but that ratio flips in a ripe banana, where sugar outnumbers starch 20 to 1.
Thanks, as usual, to McGee.