To use stevia as a powder, dry the leaves a warm, dark spot, in a dehydrator or in the oven, and then grind them. You can use a mortar and pestle, which can be fun for small batches, or put whole leaves in a coffee grinder.
Depending on the strength of the plant (stevia plants of the same variety can vary in their sweetening power depending on the glycoside content of the leaves) stevia can be up to 200 times sweeter than sugar, so do some testing before you consider adding home grown stevia to your recipes.
Another method for preserving stevia is to make a syrup or liquid from it. You can do this with either straight water (distilled water is best), or alcohol. I use vodka because it's clear, easy to find, flavorless and inexpensive. Stevia syrup prepared with alcohol has a longer shelf life too. If you don't like the idea of using alcohol in a sweetener, you can slowly evaporate some of the alcohol by keeping the liquid hot but below the boiling point for an extended period. I haven't tried this so let me know how it works out.
The less time the mixture steeps, the lighter in color it will be. I've never been able to make a clear liquid, but I think the green tint is attractive.
Stevia Syrup Recipe
6 Cups fresh stevia leaves and stems (chopped)
2 Cup vodka (Inexpensive varieties work just fine.)
4 Cups distilled water (Approx.)
Chop stevia and place in a glass or ceramic container with a tight fitting lid. Add alcohol, cover and shake. Set aside.
After 24 hours, test the mixture for sweetness. If it isn't sweet enough, let stand another 12 to 24 hours. Strain through cheesecloth. Place the strained liquid in a non-reactive pan (like glass or ceramic) and bring it to a simmer. Continue simmering for 20 minutes. Cool.
The stevia syrup will be concentrated. At this point, I usually separate the liquid into two batches. I dilute one half and keep the other half in reserve for a second batch later in winter. Because plants vary in sweetness, add enough water to your mixture to make it convenient to use. This will take some experimentation. I've tried in the past to make my liquid about equivalent in sweetness to sugar, but there's always some variation in flavor depending on the foods and cooking methods involved.
Stevia Syrup Tips and Tricks
- When processing stevia, dwell time is important. That's the amount of time you let the leaves sit in the liquid, in this case water or alcohol. With many herbs, the longer the mixture sits, the better. In the case of stevia, leaving the mixture to strengthen in flavor can also start to give it a strong aftertaste that can be bitter. For the best results, steep the leaves overnight. If it isn't strong enough, try leaving the batch another 12 to 24 hours maximum.
- Alcoholic stevia syrup will keep in the refrigerator over the winter. The longest I've used it is from November through January, so about three months. It may hold longer.
- If you want to go with a strictly water preparation, you can substitute distilled water for the vodka and cut the recipe in half. The mixture should last a couple of weeks in the refrigerator. To make subsequent batches with water over the winter, you can reconstitute dried or powdered stevia leaves in a water mixture, but you'll have to experiment with how long you can steep a batch before it starts to get bitter.
- If using cheesecloth isn't filtering out enough of the stevia leaf residue, try using a coffee filter instead.
You can add other herbs to stevia syrup to get a more complex flavor. One way is to use flavored vodka. I've tried orange vodka, which was really quite tasty. If I was going to try it again, I'd probably split flavored and unflavored vodka half and half for the recipe.
Another flavoring option is to use fresh herbs. I've made a small batch using mint, which was delicious, and think that lemon balm and pineapple sage would also be good choices.
For more information about stevia, visit:
Stevia photo courtesy of Tamara Dourney at Flickr. You can also visit her at: Saponifier