http://www.stevia.net/growingstevia.htm#unlocking-the-sweetness
Unlocking the Sweetness in Your Harvest
Once all your leaves have been harvested you will need to dry them. This can be accomplished on a screen or net. (For a larger application, an alfalfa or grain drier can be used, but about the only way an average gardener might gain access to such a device is to borrow it from a friendly neighborhood farmer). The drying process is not one that requires excessive heat; more important is good air circulation. On a moderately warm fall day, your stevia crop can be quick dried in the full sun in about 12 hours. (Drying times longer than that will lower the stevioside content of the final product.) A home dehydrator can also be used, although sun drying is the preferred method.
Crushing the dried leaves is the final step in releasing stevia’s sweetening power. This can be done either by hand or, for greater effect, in a coffee grinder or in a special blender for herbs. 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.
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