Stevia is a tropical/semitropical plant from Brazil. It's a small shrub. I just bought one yesterday ($3 at Berkeley Horticultural Nursery, for you Northern Californians). The lit on the plant says it will tolerate cold down to 21 degrees F. But the guy at the nursery thinks it will not tolerate any frost and that I should grow it as a potted plant so I can bring it inside on cold nights. The plant I got is big enough to take cuttings from, so I will try it both ways. We get light frosts here, a few nights every winter.
The plant is perennial (this means it has woody stems and lives for several years) with soft edible leaves. I tasted a bit of one and it was delish and very very sweet.
I am telling you all this because I think people understand their food better when they know where it comes from.
Stevia is an herb in the sense that it is used medicinally or as flavoring. (Botanically, an herb has soft stems that die to the ground with frost and return in the spring.) Stevia powder is made by drying the leaves and crushing them. This gives you green powder. The white powder is made by refining the crushed leaves. Much how white cane sugar is refined from molasses (though I'm sure the processes are different).
Stevia leaves have constituents that are extremely sweet. So you need very little stevia to sweeten a dish or drink. It is a form of sugar, but there are no carbs because you use so little. Stevia also has medicinal uses. It supports the pancreas and therefore is excellent for people with diabetes and other insulin problems (like most of us doing low-carb). It also has antibiotic (?) properties and is commonly used for bleeding gums.
While I was buying the stevia plant, I saw next to it another plant used for sweetening food and drink. I should have written down the name, it was Aztec something. The leaves tasted just like stevia leaves (yep, I snuck a taste). I didn't buy it cause it was $5 and I was spending all my gardening budget on an avocado tree :-).
Stevia fits into a low-carb diet in 2 ways:
You can find stevia in the dietary supplement section of your favorite health food store. An excellent brand of white powder is NOW. NOW is also available in bulk in some stores. NOW has nothing added to the stevia. Some brands add dextrose (?) in order to help the stevia flow better (it's hard to measure it out by the grain).
Most people find stevia's taste to be a bit strong. I've heard it said it tastes like licorice or fennel, but I like licorice flavor and I find stevia to be bitter. For those who are adverse to the bitter undertone, the best use of stevia is as a supplement to reduce sugar, not replace it. Desserts come out very nice with stevia and a bit of evaporated cane juice (this is a form of sugar that I used before going low-carb. You can get it organically grown. It tastes just like sugar and you use it in the same way. It is a pale tan color. It's not refined like sugar so is healthier for you, has trace minerals, etc. Of course, a carb is a carb). I don't sweeten drinks or non-dessert foods but I think stevia alone would be fine for those things you only need a touch of sweetening for. I've tried stevia in iced tea and it tastes fine.
However, with some experimentation you can eliminate most of the bitterness. Stevia tastes very sweet if you put a dab on the tongue, but if you use a little bit in a recipe, or if you use too much, the bitterness is very strong. However at the right amounts you can barely taste it (there is still a mild fennel undertone but it isn't unpleasant). When making desserts I always sweeten to taste. Add a very small amount, half a teaspoon to a teaspoon, mix well and sample. If it is still too bitter, add another small amount, and repeat this until it has the degree of sweetness you need (I have also found that if I stop when the bitterness is just at the borderline level of returning, that is often the right time to stop, particularly with dairy-based recipes like the cheesecake and the protein shake below. But, this takes a lot of practice).
Recipes
If you need any more convincing that stevia (or nothing) is a better choice than an artificial sweetener, please see Mark Gold's excellent aspartame page: http://www.holisticmed.com/aspartame/.
(posted to alt.support.diet.low-carb 10/22/98)