How to Make Leaf Powder with a Solar Dryer

People are becoming more aware of the health benefits of eating more leafy greens. Unfortunately, fresh greens have a very short shelf life. This is a real obstacle to them becoming a more important part of the diet, especially among people without refrigerators or freezers. Some dried greens, like molokhaya or jute, have long been marketed in the Middle East and Africa for use in soups. More recently powders made from other nutritious leaves have begun to come into health food markets. These are handy but can be expensive. A more economical options for low-income families is to make your own leaf powder.

Here is how:

Harvest the leaves
Wash in clear water
Drain.
Cut the leaves into pieces no more than 2 inches long.
Blanch the greens for 3 minutes in steam or in a microwave oven. This kills surface bacteria and improves the flavor of dried greens when they are stored for several months. This step is often skipped. If you choose to skip the blanching step, make extra sure that your greens are not grown in soil contaminated by livestock or by waste water. And of course, wash them well in clean water. (Leaf crops harvested well above ground level, like this abiki and jute, are much less likely to be contaminated by soil splashed up on to the leaves by rain than lower growing crops like this Swiss chard.)

Now you are ready to put your dryer to use.

Spread the cut leaves thinly on the dryer and put the cover on. You can spread more leaves on the dryer on a hot sunny day than on a cool cloudy one. You’ll want to adjust the amount of leaves so that they will dry completely in 1 day. If you can reposition the drying leaves once in the middle of the day, it will speed the process. We don’t recommend keeping the dryer out over night because the leaves often absorb water from condensation. This can lead to mold forming on the drying leaves. The maximum temperature for solar leaf dryer is about 130 Fahrenheit or 55 Celsius. When the leaves are completely dry they should feel crisp, and crumble easily when rubbed.

We usually sift the leaves at this point to remove as much stem as possible and to make a more uniform product. Stems are mainly fiber. This is in short supply in the American diet, but it can dilute the protein, vitamins and minerals needed by malnourished children.

The sifted leaves can be used as they are in soups and stews, but grinding the dried leaves allows them to be incorporated into a wider range of foods.

An inexpensive electric coffee mill does a pretty good job grinding small amounts of leaves.

A high speed blender can grind the dried leaves more finely and do it faster.

There are also non-electric options for dried leaf grinding. Hand cranked grain grinders are widely available in developing countries. They get the best results when the leaves are run through the mill 2 or more times, moving the grinding disks closer together after each pass.
Even simpler are these traditional stone grinders from Mexico and Bolivia. It is worth noting that the nutrients in finely ground leaf powder are better absorbed than in less finely ground powder. Finer powder offers much more surface area for our digestive enzymes.

Once you have dried and ground your leafy vegetables, there are dozens of ways to work them into your diet. The simplest method is to just sprinkle some leaf powder on popcorn or rice to add color, flavor, and nutrition.

You can also make leaf enriched tortillas, like this Guatemalan woman, or pasta, like this Philippina woman.

Check out the Leaf for Life website for lots of other interesting leaf enriched recipes.

Thanks!

View this video on YouTube (and subscribe to our channel at Leaf for Life @ YouTube)

Other leaf-enriched recipes are in our book 21st Century Greens. You can view (and download) that portion of the book at this link: 21stCentGreens-Appendix-1-Recipes.pdf