Ripening Bananas in The Oven
Look at the picture above. You think that doesn’t look appetizing? Well let me tell you there is nothing better for baking with bananas than a dead ripe banana. Black all-over ripe. Problem is that bananas get shipped green because they ripen after harvesting and also because they will offer purveyors a longer sell time. It is not unusual to come home with bananas that won’t be ready for baking for 5 whole days! If I want banana bread now, that just won’t do.
Thankfully someone (I have no idea who) came up with this technique of baking bananas to “ripen” them. Indeed, after a brief stint in the oven the skin blackens and the flesh sweetens and softens. While this will not work for ripening bananas to slice over your morning cereal, it does work for when you want to bake with them.
When you eat a firm banana that still has green coloration you might have had that experience of an almost puckering sensation. Bananas at this stage are not only firmer but they are mostly starch. They taste less sweet than a riper banana because they are less sweet! During ripening the starches convert to sugar. Amylase is the enzyme responsible for this conversion (and ripening) where the starch is broken down into sugars. Another enzyme called pectinase breaks down the cell walls and makes the banana feel softer. This all translates into a sweeter, creamier experience for us when we eat – and bake – ripe bananas.
To create the “ripe” bananas you see above, place your bananas peel and all on a parchment lined baking sheet. Bake in a preheated 300°F oven for about 30 minutes. Go by look and texture; it might take 5 to 10 minutes longer. They should be very dark brown, almost black all over and be soft to the touch. They should feel a bit full, like they are about to split the skins. Cool and use in any recipe that requires a ripe, mashed banana. I like to cut off them end and squeeze the soft flesh out like squeezing a toothpaste tube. Just squeeze right into your bowl or measuring cup. It is best to bake just the bananas you need and use them right away.
We consulted Harold McGee. If you don’t have his book On Food and Cooking: The Science and Lore of the Kitchen, you should order it right away. The pros turn to Harold and his book when we have questions about food chemistry. He said: “…from the descriptions I see on the web, I’d call this simple cooking and not ripening. The high heat damages the cells and so weakens and softens the structure; and the indiscriminate mixing of cell components probably does mean that enzymes convert some of the starch to sugars, as happens in baking sweet potatoes. The lower the baking temp and the slower the heating, the more starch conversion there will be, since the enzymes are knocked out as the temperature approaches the boiling point.”
He went on to suggest that we try 175°F for a longer period of time. We went back into the Test Kitchen and baked our bananas at 175°F for 3 hours. After a few trials we decided that this approach gave us slightly sweeter bananas, but there was not a huge difference in the finished results (in banana bread, for instance) from baking the bananas at 300°F for a shorter time. Our recommendation is to use the low and slow method if you have time but don’t overlook the 300°F technique. Nothing, however, beats Mother Nature. We still like naturally ripened bananas the best.
Use these for our Banana Bread and Banana Bread Mug Cake or anytime you need ripe bananas. Watch Dédé at Better.tv make the mug cake and talk about this technique.