Notes from Windward: #67


Sweet Stevia

Monique describes her work with a natural sweetener

      Cutting down on the amount of resources we need from outside of our immediate surroundings is one of the goals of sustainable living. Although we cannot completely stop relying on outside resources, diminishing our dependency on others for our produce is a key to becoming more sustainable.


     As you look around the kitchen, there are a few important items that are not produced locally. Chocolate is one, coffee is another and sugar is yet another. As we strive to use the land we have to produce a sustainable diet, the issue of luxury items becomes apparent. Although extracting chocolate and growing coffee both pose challenges, there are sugar substitutes that can be utilized by those who want or need them.

     One such sweetener, stevia, has been used by native peoples of Paraguay and Brazil for centuries. Japan has been cultivating it since the 1970's, and it currently accounts for 40% of the sweetener in their local market. Click Here

     Native stevia species grow wild in semi-tropical and semi-arid habitats ranging from grassland to mountain terrain. As a cultivated perennial it can grow in frost free areas, but it tends to lose its intensity after 3 years, so it advisable to replace it at least that often. In colder climates, "it is best to treat it as an annual herb such as basil." Click Here

     This spring, Windward purchased a flat of stevia plants as an experiment in home harvested sweeteners. Some were given to neighbors, some were planted outside, and the rest were kept in Vermadise, the greenhouse where we have grow tubes, our aquaponics model, our red earthworm population and the vault that houses our black soldier fly larvae. There were a total of 4 buckets of plants.

     Starting a few weeks ago, many of the leaves on the plants were starting to turn yellow. Because the weather had been getting increasingly colder, to the point where some of the plants inside the greenhouse started to freeze, I was concerned that we might lose our sweet crop if action was not taken. I decided to leave one bucket in the greenhouse, bring one bucket into the kitchen, and harvest the remaining two.


     I transplanted the bucket that I brought into the kitchen into a more shallow pot, because naturally stevia have very shallow roots. When you have a plant in a deep pot that prefers a shallow growing space, you end up providing an unnatural growing environment and you risk over watering the plant. As far as the harvesting goes, this turned out to be right in line with what most researchers have found; "harvesting should be done as late as possible, since cool autumn temperatures and shorter days tend to intensify the sweetness of the plants as they evolve into a reproductive state."

     As is turns out, those yellowing leaves were probably actually new shoots, which tend to develop as the days get shorter. Fearing that I had damaged half the stevia crop, I pulled cuttings from the harvested stalks and placed 8 of them in a rich soil in the kitchen. I also placed one in a jar of water, as an experiment to see which cuttings would fare better.

     After some further research, I discovered that growing stevia from cuttings can be a challenge. "Stevia has a temperamental nature that is often reflected in slow growth when the plants are first set out." Regardless, I had reached the point of no return. As recommended, I dipped the three-inch cuttings in rooting hormone before planting them. I have been misting them frequently, and for the past few weeks they have had 12-14 hours of artificial light, and about 9 hours of natural light, with 9 hours of overlap. Unfortunately, they don't seem to be doing very well. "Even under ideal conditions, it's not uncommon for plants to die suddenly or to lose leaves and appear dead, but as long as the roots are alive, they may regrow." Click Here


     Since I have been taking good care of them, I am hoping for the best. Perhaps even though they look wilted and dried, they are dropping roots. As far as I can tell, we probably won't know how they fare until the spring, when we can hope for new shoots to appear. Until then, I am going to keep misting them frequently, allowing that to be the only source of moisture, as the stevia prefer drier soil. Overall, it seems that the water rooted cutting looks better off, despite my assumption that since it prefers a drier soil, it would not fare well in a water solution.

     The transplanted stevia in the kitchen seems to be doing the same as the one out in Vermadise, so as of now, it's a toss up over what the best option is for over-wintering. Regardless of what happens with the plants, we also have the harvested leaves to experiment with.


     We hung the leaves to dry, and after about a week they were ready to be crushed. We crushed them with a mortar and pistol. One thing to keep in mind when using stevia is that it is much stronger then sugar, "one dried leaf, ground, is 10 to 15 times sweeter than an equal amount of sugar, and powdered extracts made from the leaves are up to 300 times as sweet." That being said, a tiny amount of crushed leaves should be enough for a cup of tea or coffee. Click Here


     If the idea of using fresh herbs appeals to you more, you can use stevia as an addition to salads, but please keep in mind that a little goes a long ways. I have used the fresh leaves as a sweeter in tea, one leaf is good for one cup. "You can also make your own liquid stevia extract by adding a cup of warm water to 1/4 cup of fresh, finely-crushed stevia leaves. This mixture should set for 24 hours and then be refrigerated." Click Here

     I have read conflicting data on the use of stevia in cooking. Some say that it cannot be raised above 275 F°, which includes most baking, but else where I have read that it is not at all affected by heat. We plan on testing its effectiveness as a sweetener in baking in the next few days. Check back for the results!

Notes From Windward - Index - Vol. 67