Tinctures preserve the active compounds of plants indefinitely, or at least long enough for one to feel that way. A good tincture should last for twenty years if stored in a cool dry place away from the sunlight. Tincture bottles are amber or dark blue on purpose, to keep out ultraviolet light and preserve the quality of the product.

Tinctures are obtained through the maceration of plant material in alcohol. If your base is vinegar or glycerin, it's not a tincture, it's an extract. Keep in mind that many tinctures are administered orally, so the alcohol should be safe to drink and odorless (vodka works best).

To make a tincture or an extract, pack a jar with plant material and add the carrier medium of your choice to completely cover it. Seal the jar tight so no air can get in, place it in a warm spot, away from the sunlight, and shake it two or three times a day for two weeks.

When finished, strain the tincture or extract through a strainer lined with coffee filters and store it in a colored glass bottle, away from the sunlight.

You can repeat the process, if at the end of the two-week period the tincture is not concentrated enough, by adding fresh plant material to the already infused carrier base.

Tinctures are administered in small quantities, by the dropper or by the teaspoon, and can be prepared for culinary uses as well as medicinal ones (many of the naturally extracted food flavorings at the grocery store are tinctures).

Author's Bio: 

Main Areas: Garden Writing; Sustainable Gardening; Homegrown Harvest
Published Books: “Terra Two”; “Generations”; "The Plant - A Steampunk Story"; "Letters to Lelia"; "Fair"; "Door Number Eight"; "A Year and A Day"; "Möbius' Code"; "Between Mirrors"
Career Focus: Author; Consummate Gardener;
Affiliation: All Year Garden; The Weekly Gardener; Francis Rosenfeld's Blog

I started blogging in 2010, to share the joy of growing all things green and the beauty of the garden through the seasons. Two garden blogs were born: allyeargarden.com and theweeklygardener.com, a periodical that followed it one year later. I wanted to assemble an informal compendium of the things I learned from my grandfather, wonderful books, educational websites, and my own experience, in the hope that other people might use it in their own gardening practice.