By Dr. Mercola
The herb stevia is one of my favorite options for an occasional sweetener. It's a safe, natural plant that has been around for more than 1,500 years. Stevia is up to 200 times sweeter than sugar and does not spike your blood sugar, making it an ideal substitute for diabetics and dieters alike. Stevia is often a better choice than honey, maple syrup and molasses. Particularly if you've been using artificial sweeteners, you will want to give stevia a try.
If you are trying to lose weight or simply reduce your consumption of sugary sweets, stevia can be an appealing alternative to sugar. If you buy stevia from the store, take care to read the ingredient labels. Some brands actually contain sugar! Inexpensive stevia generally contains one or more additives that are potentially harmful to your health, such as erythritol and maltodextrin. If you want access to stevia that is safe and healthy, your best bet is to grow your own.
The History of Stevia: Used for Hundreds of Years in South America
Stevia is a perennial herb found within the Asteraceae family, which means it's related to daisies, marigolds, ragweed and sunflowers. Several species of stevia called candyleaf are native to Arizona, New Mexico and Texas.1 The prized species, Stevia rebaudiana, grows in Brazil and Paraguay, where its leaves have been used for hundreds of years to sweeten food and drink.
Although the U.S. Food and Drug Administration (FDA) initially withheld approval of stevia in 1991, they approved the use of rebaudioside compounds derived from the stevia plant in 2008.2 At the time, Coca-Cola introduced its zero-calorie, stevia-based sweetener called Truvia, while PepsiCo rolled out PureVia — both products used rebiana, a stevia extract.3
A mature stevia plant can grow to about 2 feet tall and has small, moderately broad, green leaves. Stevia has a distinctive aftertaste characterized as slightly bitter and licorice-flavored. It is well-suited for sweetening creamy desserts, drinks, fruit, salad dressings and yogurt. You can sweeten hot beverages, such as tea, simply by placing stevia leaves directly into the liquid.
Cold beverages are best sweetened using dried or liquid stevia. Those forms are also best for baking and cooking. No matter which type you use, you may need to experiment a bit to arrive at the right balance of stevia and other ingredients, particularly with respect to the flavor and taste of baked items.
Planting Stevia: Keep in Mind It Is a Poor Germinator
Stevia is not your typical herb, and it is not as easy to grow as most culinary herbs. With patience, however, it can be grown successfully in U.S. Department of Agriculture Plant Hardiness Zones 11 and up. Stevia thrives in semi-humid locations with acidic soil, and does best when started indoors. Take note that stevia is very poor germinator, and a germination rate of less than 10 percent is common. When planting stevia, be sure to:4,5,6,7
- Start seeds indoors about 12 weeks prior to the last frost
- Plan for well-draining soil with a pH ranging from 6.7 to 7.2
- Anticipate a very low germination rate by placing at least three seeds in each planting cell; some suggest darker (mature) seeds are more likely to sprout than those of lighter colors
- Use a germination mat or overhead "grow" lights
When stevia plants have achieved six to eight weeks of growth, you can transplant them in your garden, assuming nighttime temperatures are consistently above 50 degrees F. If not, move your young plants to 3-inch pots and maintain them indoors until the weather warms up.
When transplanting to your garden, space plants 8 to 10 inches apart, and maintain rows 2 feet apart. Stevia grows best in full sun to partial shade. Plants will thrive in compost-rich, light sandy or loamy soils that are well-drained, but cannot handle wet soils. Applying a light mulch around your plants will help maintain moisture to the roots.
Stevia grown in warm climates will grow as much as 24 inches tall, whereas plants grown in cooler areas will top off around 16 inches. To get a year's supply of dried leaves, you should plan to grow at least three plants. Some growers start stevia from cuttings, which is easier than trying to sprout seeds, especially given the poor germination rate.
Particularly if you are in a warm weather area and intend to grow stevia as a perennial, you may want to consider growing it from cuttings. Look for stevia in the herb section at your local nursery, and keep in mind the sweetness of the leaves varies from type to type.
Pruning is important for stevia's characteristic lanky and upright plants.8 To maximize leaf production, you will want to trim back your plants several times to encourage branching. Perform the first pruning when plants are about 8 inches tall. Prune again in early summer. You have two options for using the pinch-backed stems: Harvest the leaves from them, or root them in moist potting soil to cultivate additional stevia plants for yourself or a friend.
Harvesting Stevia Leaves
Stevia blooms in early to midfall, displaying crisp white flowers. Take care when weeding around stevia because its branches are somewhat brittle. Fortunately, stevia is not prone to diseases or pests, perhaps due to its sweetness, which acts as a natural defense mechanism. While nontoxic, stevia plants have been found to possess insect-repelling tendencies against aphids and other bugs that do not care for its sweet taste.
While stevia can be harvested all summer long, the sweetness of the leaves improves when the weather turns cooler.9 To ensure the tastiest leaves, plan to harvest your stevia in late September or early October.10 You'll want to harvest the entire plant as soon as four to five flower buds have appeared but before they have opened.
Because the sugar content of the leaves is highest early in the day, plan to harvest leaves in morning. If you wait to harvest until most of the flowers have blossomed, expect an increasingly bitter aftertaste to be distributed throughout the plant. Stevia leaves keep best when dried. Store your dried stevia leaves in an airtight container alongside other herbs. It is best to crush the leaves only when you're ready to use them. Similar to other herbs, you can dry stevia by:11,12
- Bundling their stems and hanging them from a hook or nail until dried
- Drying them in a food dehydrator at 95 to 110 degrees F
- Placing them in an oven preheated to 180 degrees F and heating until crisp
Although stevia does best in warmer climates, it has been known to overwinter in areas as low as zone 8.13,14 That said, when growing stevia in a colder climate, plan to grow it as an annual by overwintering your plants indoors to protect them against frost. If you live in zone 8 or warmer, stevia is generally winter-hardy and will grow as a short-lived perennial when provided with a protective winter mulch.
If you live in a colder climate, you can choose two healthy, 1-year-old plants to overwinter indoors. To prepare them for overwintering, cut them back to a height of 6 inches. Prune their roots as needed to accommodate their transfer to 6-inch pots filled with potting mix. Place the plants in a warm, sunny location indoors, or in a heated greenhouse.
In spring, when new growth appears, you will want to cut most of the new stems and use them as cuttings to start additional plants. Cuttings can take root in two to three weeks when placed in a moist seed-starting mix or perlite.15
Health Benefits of Stevia
Besides being a zero-calorie sweetener with appeal to diabetics and dieters, stevia:16,17,18
- Acts as a natural antioxidant — due to the presence of caffeic acid, flavonoids, kaempferol, quercetin, tannins and triterpenes — enabling your body to fight free radicals that can damage your cells and contribute to cancer, heart disease and other health concerns
- Inhibits the growth of cavity-promoting bacteria and is also believed to prevent dental cavities and gingivitis
- Promotes weight loss, which means you can enjoy "sweets" without the calorie burden and negative effects of sugar
- Reduces high blood pressure, thereby protecting your heart health, due to the presence of glycosides in stevia known to relax your blood vessels
- Regulates your blood sugar level, as the glucose-containing particles of stevia is absorbed in your colon and not your bloodstream, like sucrose (table sugar)
While stevia has been deemed generally recognized as safe by the FDA, and has been enjoyed by South Americans for hundreds of years, you will want to avoid it if you have an allergy to other members of the Asteraceae family, such as ragweed. Some people have reported bloating and cramping after eating stevia, as well as dizziness and headaches. If you experience any of these side effects, you should stop using stevia. Fortunately, side effects are rare, and stevia is easy to process at home.
Processing Stevia at Home
If you are familiar with stevia, you know that slightly under-sweetening drinks and baked goods is much preferred to using too much, which can result in a sharply bitter flavor. If you use stevia regularly for baking and cooking, it is well worth your time to become familiar with a stevia-to-sugar equivalence chart.19
Keep in mind homegrown stevia will not be as potent as store-bought varieties, mainly due to the processing methods involved. To ensure you have a ready supply of it for all your sweetening needs, below are three methods for processing stevia at home:20
• Stevia tea: Add 1 rounded tablespoon of dried, lightly crushed stevia leaves to a metal tea ball. Place the ball into a clean pint-sized canning jar and add near-boiling water. Steep for 10 minutes and then remove the tea ball. After the liquid cools, put a lid on the jar and store it in the refrigerator for up to five days. Yield: 2 cups of liquid stevia with the approximate sweetness of 2 cups of sugar.
• Stevia extract: Add one-half cup lightly crushed stevia leaves to 1 cup of near-boiling water. Remove from heat, cover and steep for 40 minutes. Strain the liquid and pour into a dark-colored glass container. Store in your refrigerator for up to two weeks. Yield: 3/4 cup of stevia extract with the approximate sweetness of 3 cups of sugar.
• Stevia tincture: Place one-half cup dried, lightly crushed stevia leaves in a clean glass jar and add 3/4 cup 100-proof rum or vodka. Secure the lid and shake thoroughly. Place the jar in a cool, dark place and shake daily for the next two days. Remove the lid, strain the liquid and heat it in a small saucepan on low until steam rises.
Maintain the temperature (do not boil) for 20 to 30 minutes. Most of the alcohol smell and taste will dissolve, creating a more concentrated tincture. Remove it from the heat and allow it to cool. Pour the liquid into a dark-colored container, preferably one with a dropper top. Store in the refrigerator for up to three months. Yield: About 1/4 cup of stevia tincture with the approximate sweetness of 6 cups of sugar.
Stevia Is the Best Sweetener Available Today
Stevia is one of the best sweeteners available today. Some shy away from it due to its bitter aftertaste, but that is usually a reflection of how it was processed. When you buy a reputable brand, it only takes a few drops to sweeten a drink.
While stevia is calorie-free and a great alternative to sugar, and most certainly a better choice than artificial sweeteners, I still recommend using it in moderation, just as you would sugar. Although it is widely available for purchase, to ensure you get a 100-percent natural product, you may want to grow your own.