Postcard from Hawai’i – Dried Bananas

We are attempting to deal with our banana surplus issue.

A bunch of bananas is too much fruit for us to use in the few days before they spoil. A single bunch can yield 50 to 60 bananas. We snack on bananas, we make smoothies, we slice bananas onto our morning cereal, it is still too many bananas. Our standard answer to avoid waste is to give away much of the fruit. Apple bananas are quite popular and quickly accepted when given away to neighbors an co-workers.

Dehydrated Bananas
A batch of bananas in the dehydrator
Still, it is a long time between bunches, feast and famine, and I would like to have bananas around more often. We have tried freezing, but are not entirely happy with the results, and our freezer space is limited.

This time we are trying dried bananas using a recently purchased food dehydrator. A bit of an experiment, I have never done this before. I dimly remember my mother drying bananas when I was a kid, I do remember the results being pretty good.

What is not so clear in my memory is the process needed to obtain good results. Time for Google! Reading a number of online articles about drying bananas and comparing the methods I find a few common hints. It seems bananas should be done slowly, at a little lower temperature, about 65°C. A pretreatment of lemon juice is highly recommended. Dry until tough but not crisp.

More Bananas
Another bunch of bananas ready for harvest
Lemons? None on hand. Our lime tree has no fruit at the moment, but I do have plenty of grapefruit. So I use grapefruit instead, squeezing a few to make a bath for the banana slices. The grapefruit adds a tart taste and does prevent browning, a successful substitution.

Temperature? I have no idea what the low-medium-high settings on the new machine might actually mean. Get out a thermocouple to monitor. Hmm, been a while since I used it, the thermocouple amplifier is in need of a new battery and a calibration check… done. A kitchen offers both ice-water and boiling water, accurate calibration standards. It appears setting the dehydrator to medium is the right answer, giving about 63°C at the exhaust of the heater unit. High gives about 75°C, a little hot for bananas if the online sources are to be believed.

If you check the image above you will see the thermocouple amplifier attached to a digital meter. The sharp eyed my also note the Kill-A-Watt power meter on the cord. This is measuring the power used by the dehydrator. It looks like it takes 4-5kWh to dry a batch of fruit, a couple dollars worth of electricity, quite acceptable. Yes, I am a nerd.

The results? Pretty good so far, just finishing up as I write this. I need about one or two hours more. Looking forward to having bananas to munch on for the coming month. The next bunch from the banana patch is at least a month out, perhaps two.

Author: Andrew

An electrical engineer, amateur astronomer, and diver, living and working on the island of Hawaiʻi.

3 thoughts on “Postcard from Hawai’i – Dried Bananas”

  1. Interesting that you have a watt hour meter and thermo probe handy. But no moisture meter to check the water content of your banana chips as they are drying, for optimal results? What kind of nerdy engineer are you? (just kidding)
    I usually just snack on the chips, or add them to cereal or trail mix. Some people cook and bake with them too.

  2. I have had better luck cutting the bananas into wedges, usually just quarters, unless it’s a really fat banana, rather than chips. The texture is nicer. Enjoy!

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