One way to prolong the shelf life of fruit and vegetables is to dry them. If they are dried until crisp and brittle, they will keep for a very long time indeed. If they are partly dried, but still remain pliable, they should still keep for at least 2 months or so.
Drying can be done in an oven with the door partly open (110 Centigrade, Gas Mark 1/4). That should take around 8 hours for apple rings. But it can also be done in an airy room, in which case it takes several days.
This year, the apple drying season happened to coincide with replacing a noisy computer fan. In an inspired piece of recycling, the old fan was connected to an unused phone charger, and used to blow warm air from the radiator over the aple rings. The charger provides enough power for the fan to be effective, but it turns slower than in the computer, so it runs smoothly and quietly. The new fan assisted drying seems to reduce the drying time by at least a day.
Discolouring of fruit, like apples, can be prevented by dipping in either lemon juice (3 Tablespoons in 1/2 Litre water) or Ascorbic acid solution (1 Tablespoon crystals in 1/2 Litre water) before drying.
So the steps to making dried apple rings are:
Thanks to Rich and Christopher for showing how apparently redundant computer and phone parts destined for landfill can actually be used simply for something useful. Add a solar array and it would be sustainable as well. I have a cunning plan for using this system to help some paint dry – should be worth watching