Tinctures are usually made by soaking herbs in alcohol. The alcohol base preserves the herb’s potency for a long time, often for two years or more. Since sunlight can destroy the effectiveness of herbs, tinctures are packaged in dark bottles that should always be stored in a cool, dark place[…] The different substances within a tincture may separate, so always shake the bottle vigorously […] If you are avoiding alcohol for any reason […] add the appropriate dose of tincture to one-half cup of very warm water; let it stand for 10 minutes. By the time the water is cool enough to drink, most of the alcohol will have evaporated.
Complete Guide to Safe Herbs-page 16