Cardboard solar dehydrator
By Karin Weijers
My dear friends Helder and Karen asked me to write an article about dried food, like fruit and vegetables. The main reason to dry your fruit or vegetables is because your garden is producing more than you can use at that moment. Of course there are other methods preserving your crops for a longer time period. Why drying, it is easy to do yourself, you can dry nearly everything, it keeps the vitamins and minerals in the original state (if the temperature is not above 41 degrees Celsius), if you use a self-made solar dehydrator it does not use external energy like gas or electricity, easy to store and it will stay for a long time.
Before you want to use dried food it is better to soak it in water, it returns to the original shape. After this you can eat or prepare a healthy meal. Of course you can eat the dried food without soaking but I suggest you drink some water and chew very good. Some more facts about dry fruit you will find in this interesting link
You can make banana, apple, beetroot, carrot, sweet potato, cassava as chips or even mushrooms or soak your favorite vegetables in a marinate and dry them so that you can get a nice flavour.
Kale chips recipe
1 large bunch kale, any variety
2 - 3 teaspoons extra-virgin olive oil
3/4 teaspoon salt
Strip the leaves away from the leafstalks and tough midribs (if you dry the whole leaves, the midribs end up with the consistency of twigs - not tasty!). Compost the leafstalks or save for soup stock.
Wash the kale leaves and dry well in a salad spinner or by gently rolling the leaves in a clean dishtowel.
Tear the washed and dried leaves into just slightly larger than chip sized pieces; they will shrink slightly as they dry. Toss the kale in a large bowl with the extra-virgin olive oil and the salt. Massage the leaves well with your clean hands. All of the leaves should be more or less evenly coated with the oil. If you like spicy flavors, add a dash of cayenne pepper. Nutritional yeast will add a cheesy flavor.
This link gives you some does and don'ts while drying fruits
And now the design for our homescale project
Made from two cardboard boxes, some clear plastic wrap, and a little tape. You can build a nearly free solar dehydrator.
Set it on a stool or chair and face it's solar collector towards the sun, and you have a functional food preservation machine for little work and even less money.
The above picture almost says it all. Using a long thin cardboard box for the collector and a taller, nearly square, cardboard box for the drying box.
If you use spray paint or other toxic paints, let the collector bake in the sun for a day or two before use.
To increase the efficiency, you may want to cover the sides and bottom of both boxes with fiberglass or styrofoam insulation.
Drawing courtesy of: Mother's Energy Efficiency Book Copyright 1983 ISBN 0-938-43205-2
TESTS FOR DRYNESS:
Rely on appearance and feel to judge dryness.Cool a test handful a few minutes before deciding whether the food is done.Consider fruit dry when no wetness can be squeezed from a piece which has been cut - it should be rather tough and pliable.Consider vegetables dry when brittle.
PRE- AND POST-DRYING TREATMENTS FOR FRUITS & VEGETABLES:
Steam blanching is safe pre-treatment which can prevent spoilage - especially of low acid foods such as vegetables.
Important post-drying treatments are:Conditioning - i.e. leaving in open air for long periods to equalize moisture content.Pasteurizing - i.e. exposing the dried foods to high heat to eliminate harmful organisms
Ensure food is thoroughly cool before storing.Store in small quantities in glass or food-grade plastic.Check supplies frequently for contamination or dampness.Keep in a dry, cool place (between 4 C/40 F and 21 C/70 F).
PREPARING FOR EATING:
Fruits - cover with boiling water in saucepan and simmer the fruit covered for 10-15 min.- sweeten to taste at the very end of cooking.- remove from heat and cool still covered Vegetables.- soak all vegetables except greens in cold water until they are nearly restored to their original texture.- use only enough water to cover and always cook in the soaking water.- cover greens with enough boiling water to cover and simmer until tender.