Stevia (S. Rebaudiana) is an herb with leaves that taste many times sweeter than sugar. Because it is not sugar, it is safe for diabetics. Also, it does not cause tooth decay or other health problems associated with sugar such as weight gain. Stevia is a perennial shrub that is native to South America. It can be grown in USDA Plant Hardiness zones 8 and warmer and as an annual everywhere else. The plant grows quickly and flops over by midsummer but can be cut back by half to encourage new and thicker growth. The blooms are white and small and should be removed before the plant expends energy making seed. The seed does not germinate dependably, so stevia plants are usually propagated by root divisions or cuttings.
Remove leaves for harvest from the stevia plant before it begins to bloom. If blooms are forming on the plant, cut the plant back by half to increase leaf production and delay the bloom period and harvest the leaves from the cut sections. The taste of the leaves have a bitter taste after the plant blooms. For using in drinks, simply add as many slightly bruised or crushed fresh leaves directly to the drink as needed to sweeten the beverage. For baking, you will need to harvest, dry and process the leaves.
Harvest as many leaves as you need for use and storage. One cup packed with fresh leaves makes about 1 tsp. of dried powdered leaves.
Set the leaves out in one layer in a warm (65 to 75 degree Fahenheit) and dry place to dry. If the place you dry the leaves is dark, the leaf color will be better preserved. You can also place the leaves in a dehydrator or a warm oven set at 150 F. Whatever method you prefer, you need to check the progress often because the leaves dry quickly. The leaves are ready as soon as they are dry enough that you can easily crush them to a fine powder when rubbed together in your hands.
Wash and dry your hands very well, then crush the dried leaves by finely crumbling them between your fingers or palms. Crush to a fine powder. Dried stevia leaves are very light and easy to process. Store the crushed leaves in a clean glass jar with a tight fitting lid.
Use the leaves as a sugar substitute when cooking at the rate of 1 tsp. of dried stevia leaves to 1 cup of sugar. Do not overuse. Using too much stevia in cooking can make what you are sweetening have a bitter aftertaste.