Fruit – How to know if a black banana is too old to be eaten

It likely depends on what 'turning bad' means ...

If you have a couple in the bag starting to sprout, but the rest haven't, you can roast or bake the ones that haven't sprouted, let them cool, then store then in the fridge so you can pull them out to use them in something later in the week. (eg. home fries, patatas bravas or a hash).

For those that have started to sprout, but are still firm, you can cut away the sprouted bits (this time of year, you might even be able to plant them), peel them, and then boil them and turn 'em into mashed potatoes (which you can then vary for the next couple of days ... you can mash 'em with other stuff to make a sort of potato salad; you can add cooked greens to make colcannon or bubble and squeek; you can use as a topping for a cottage pie (the technically correct term for shepherds pie when you're not using mutton or lamb)

Some of these freeze well ... I've made up cottage pies and frozen 'em in oven-proof containers; you could likely do the same with just mashed potatoes -- I see 'em for sale in the grocery store all the time.

If you're looking for something to cook that just uses a lot of potatoes (in a non-whole state, in case you need to cut away parts) ... potato salad, potato bread, potato curry, latkes, potato soup, tortilla de patatas ... the list goes on.

... and if they're soft and squishy, or oozing liquid ... pitch them. They're rotting, and not worth getting sick over.

1. Turn the oven down by about 25-50F. Quite often, ovens just blast the heck out of baked good, especially smaller apartment ovens. Larger, more expensive ovens tend to be better calibrated and will produce the proper 350F temperature usually required for banana bread. A cheap oven, which is still fine for banana bread, will overshoot the temperature and kill your banana bread. Turn the oven down a bit, and if necessary cook for longer. I have even turned my oven cooler AND cooked it for 15 minutes less time than the recipe required.

2. Check at 2/3 time. Don't let the bread run through the entire cooking time before checking it. Always check early. For some recipes, I take the banana bread out at 2/3 recommended time!

3. Don't over-beat the mixture. Despite being called banana "bread" it isn't a bread, it is a cake insomuch as it is made from a batter, not a long-kneaded dough. If you start mixing and it seems already too dry - STOP - and add a few tablespoons of milk to loosen the mixture up. If it's too dry in the initial stages, it will certainly be dry later, but a dry mixture also causes you to push harder, thereby causing the gluten to harden.

4. Don't cut down on butter/fat. This is really what prevents it drying out. Use creme fraiche, more butter, a bit less flour...