Thickeners

Strategies, Tips, and Tricks for Using These Cooking Agents

by Debra Daniels-Zeller

Deciding which thickening agent to use can be tricky. Questions frequently arise. What can I use instead of gelatin? Are arrowroot and cornstarch really interchangeable? How do I thicken a gravy if my guests can't eat wheat? And how does arrowroot, tapioca flour, or potato starch function in a muffin recipe? Each thickening ingredient has unique qualities, and each performs differently.

Over the years, I've used these thickening options in a variety of ways, but I wanted to experiment with all of them at the same time to answer my own questions. How was each different in a gravy, sauce, or fruit dessert? Before I started, I mentioned my idea to Devra Gartenstein, author of The Accidental Vegan and owner of the Patty Pan Grill, which serves healthy vegetarian fast food in Seattle. Devra asked, "Are you going to use rice flour?"

"How do you use it?" I asked.

"Sprinkle a little over the top of a simmering sauce and stir, and it thickens right up," Devra answered.

I love new cooking tips, so I went home and sprinkled rice flour over simmering mushroom stock. Like magic, it had the same amazing texture as my grandma's gravy, which was always thickened with a flour-fat roux with stock gradually added. But with rice flour, I didn't worry about lumps of roux in the gravy. Rice flour is now a staple thickener option in my pantry.

But I was still curious about agar, arrowroot, cornstarch, kuzu, potato starch, and tapioca flour. How did they perform with liquid? Was one equal to another? My experiment would reveal the answer. I measured a Tablespoon of each thickener into separate containers and added 8 ounces of cold water. One by one, I poured each mixture into a small pan. I stirred and simmered until the liquid thickened. The results revealed why, for example, my cobblers turn out differently if I substitute arrowroot or kuzu for cornstarch.

Thickening Options

Agar (also called agar-agar or kanten)

Agar is a vegetarian gelling agent made from red algae from the ocean. Agar is a perfect substitute for gelatin, which is derived from animal ligaments and cartilage. A staple ingredient in Japanese cuisine for centuries, agar is used to create gelatin-like desserts or aspics. Agar is available in flakes, powder, or bars that are called kanten. The powder is more processed than agar flakes, which are a staple in my pantry. Kanten is more difficult to find.

I cooked the agar-water experiment until the flakes dissolved, usually 4 to 10 minutes. (The time is determined by how hot and fast your stove simmers.) With practice, you'll find it is easy to see exactly when all the flakes dissolve. When done, my experiment was as thick as corn or maple syrup. I removed it from the heat and poured it into a gelatin mold. In 30 minutes, it had gelled. If you forget the liquid-to-agar ratio, there are directions on the back of the agar package.

Agar is available in Asian markets and in the international aisle of natural foods stores.

Arrowroot

A Caribbean dietary staple, arrowroot is derived from the roots of a tropical plant and has been cultivated for 7,000 years. Use arrowroot to thicken sauces, or add it to baked goods with gluten-free flours like buckwheat to help bind the flour. Arrowroot creates texture for muffins or cookies similar to wheat flour. It has a slightly gritty texture, but it's not as gritty as rice flour. Some cooks use arrowroot exclusively to replace the flour that many recipes require.

Arrowroot-based sauces are very similar to cornstarch-thickened mixtures. The hot liquid becomes clear as the mixture thickens, but if overstirred and heated too long, the mixture becomes thin again. I have used it hundreds of times and never had this happen, but perhaps this is why it is not very effective to thicken pie fillings. I suggest that you remove the arrowroot mixture from the heat after 10 to 12 minutes rather than letting it simmer for half an hour. When substituting arrowroot for cornstarch, use 1 Tablespoon arrowroot for every 2 teaspoons of cornstarch.

My arrowroot experiment was half as thick as the cornstarch-water combination when it was done. If you need a thick pudding consistency, use more arrowroot or use the more dependable cornstarch.

Look for arrowroot in natural foods stores.

Cornstarch

Cornstarch was first manufactured in the 1840s. Made from a substance extracted from corn and processed into a white powder, cornstarch was originally used as a clothing starch. Food manufacturers soon discovered they could add it as a filler to processed foods. Cornstarch can be added to replace approximately a quarter of the flour in cake and cookie recipes for a finer grained, lighter product.

My cornstarch-water mixture thickened faster than my arrowroot one did. Like arrowroot, cornstarch is said to revert to a thin consistency if cooked too long or stirred too much. (This may be the reason some cooks have better luck using wheat flour to thicken berry pie filling.) My thickened experiment had more substance than the arrowroot-, kuzu-, or tapioca-water mixture. However, cornstarch is more dependable to use if you're aiming for a pudding-like consistency.

My cornstarch experiment was clear when it was hot, but it turned opaque and was thicker when cool. It left a slightly chalky, unappealing aftertaste. If you have delicate flavors, it may be worthwhile to use arrowroot instead of cornstarch.

Cornstarch is available in the baking aisle of any grocery store.

Kuzu (also called kudzu)

Kuzu has been used as a cooking ingredient in Japan for more than 2,000 years. Some cooks prefer to use kuzu instead of arrowroot or cornstarch because kuzu is less processed.

In my experiment, I crushed the small hard kuzu lumps in a mortar with a pestle before measuring the kuzu powder into cold water. Always remember to do this before using it; otherwise, the lumps may remain intact. As my experiment heated, it was difficult to tell when the mixture had thickened because the texture was only slightly thicker than water after simmering for 10 minutes. I recommend using twice as much kuzu as cornstarch to thicken a sauce. When cooking, stir continuously or the kuzu will drift to the bottom of the pan, stick, and form a thick hard layer.

Find kuzu in Asian grocery stores and in the international aisle or the macrobiotic section of natural foods stores.

Potato Starch

Made from cooked, dried, ground potatoes, potato starch can thicken hot liquids and is used as a binder in processed gluten-free breads and cookies. The package I purchased indicated that potato starch can be substituted for wheat flour to thicken gravy, sauces, or soups. However, in my experiment, the simmering liquid suddenly bubbled up and became a soft-gelled mass—not exactly gravy texture. For a gravy or sauce, my recommendation is to use less than half as much potato starch as cornstarch in a recipe and expect thicker results.

Potato starch creates excellent texture when used as a binder in baked goods made with a gluten-free flour, such as rice, millet, or buckwheat flour. I use it almost exclusively to make my favorite buckwheat crackers. Use half as much potato starch as flour in a recipe.

Potato starch is available in natural foods stores and in specialty markets.

Rice Flour

Used in Japan for centuries, this gluten-free flour can be sprinkled directly into a hot sauce or soup to thicken the texture. And it's so easy to use that my gravy turned out perfectly with my first try. Start out with a Tablespoon of rice flour. Sprinkle over the simmering liquid. Add more as needed.

Rice flour can be found in the baking aisle of many grocery stores and natural foods stores.

Tapioca Flour

Tapioca is a traditional ingredient in Brazilian foods, processed from the root of the South American cassava plant. Tapioca is available in granules, flakes, pellets, and flour, and it was the main ingredient to thicken pudding in the United States for decades until other ingredients replaced it.

In my experiment, tapioca thickened the water like cornstarch did but with thinner results. Tapioca performs more like arrowroot in sauces. Use twice the amount of tapioca as cornstarch in a recipe.

Tapioca flour shines as a binding ingredient in gluten-free bread, muffin, and cookie recipes. Use at least half a cup of tapioca flour for each cup of gluten-free flour.

Tapioca flour is available in natural foods stores and in the baking aisle of some grocery stores.

Wheat Flour

My grandmother depended on wheat flour to thicken gravies, stews, and hot fruit pie fillings. Typical gravy ingredients are fat, flour, and stock. The fat and flour are blended together in equal amounts over medium heat to make a roux. The liquid is then stirred in gradually. For pie fillings, grandma knew what she was doing when she sprinkled flour over the fruit to help absorb the juices and make a thicker filling.

Wheat flour is available in the baking aisle of most grocery stores.

Summary

To gel anything or to replace gelatin in a recipe, select agar. It can also be used in frozen dessert recipes and to thicken puddings. Cornstarch is the thickener of choice for puddings, but if you prefer more healthful alternatives, use arrowroot or kuzu and add about twice as much of either one as you would cornstarch. Tapioca works much the same as cornstarch, but you must add more of it to thicken a sauce or gravy. Rice flour is an easy option to thicken a sauce or gravy. Just sprinkle over the simmering liquid. Use wheat flour in pies and fruit desserts that must be cooked for long periods. Arrowroot, potato starch, and tapioca flour are excellent binding ingredients for gluten-free flour in baking recipes.

Vegan Thickening Options
*Prices reflect natural foods stores on the West Coast; actual prices in other areas may vary.

OPTION AVAILABILITY PRICE PER OZ.* STOVE TOP BAKING BEST FOR
Agar Natural Foods Stores, Asian Markets $5.99 Gelling Agent No Gelled Desserts
Arrowroot Natural Foods Stores $ .57 Sauces, Gravies, Fruit Desserts Yes Sauces, Baking
Cornstarch
- Organic
Grocery Stores $ .09
$ .50
Sauces, Gravies, Fruit Desserts, Puddings Yes Sauces, Puddings, Fruit Desserts
Kuzu Natural Foods Stores, Asian Markets $1.26 Sauces, Soups No Sauces, Soups
Potato Starch Natural Foods Stores, Grocery Stores $ .13 N/A Yes Baking
Rice Flour Natural Foods Stores, Grocery Stores $ .25 Sauces, Gravies Yes Sauces
Tapioca Flour Natural Foods Stores, Grocery Stores $ .13 Sauces, Gravies,Puddings Yes Baking, Sauces
Wheat Flour Grocery Stores $ .03 Gravies, Pies Yes Fruit Pies

Recipes

EASY SCRAMBLED TOFU

(Serves 2)

Drain and discard the water in the tofu package before using. Arrowroot is sprinkled onto the tofu to create a soft, egg-like texture. Nutritional yeast adds a cheesy flavor.

½ teaspoon oil
1 small onion, chopped
2 cloves garlic, minced or pressed
¼ cup chopped green or red bell peppers
1 cup sliced button, crimini, shiitake, or portobello mushrooms
8 ounces firm or extra firm tofu, drained
1 Tablespoon nutritional yeast
1 Tablespoon arrowroot
¼ teaspoon turmeric
2 Tablespoons salsa
½ teaspoon salt
¼ cup chopped cilantro or parsley

Heat a heavy skillet over medium heat. Add oil and onions. Stir, then cover with a lid. Turn heat to low and sweat the onions for 10 minutes, stirring occasionally. Remove lid and add garlic, bell peppers, and mushrooms. Cover and cook until mushrooms are slightly soft and garlic is lightly browned.

Crumble tofu over the onions and mushrooms. Sprinkle the nutritional yeast, arrowroot, turmeric, and salsa over the tofu. Stir and cook over medium heat for approximately 7 minutes or until the tofu is heated through. Blend in the salt and serve garnished with chopped cilantro or parsley.

Total calories per serving: 166 Fat: 7 grams
Carbohydrates: 17 grams Protein: 14 grams
Sodium: 669 milligrams Fiber: 4 grams

STIR-FRY VEGETABLES WITH HOISIN SAUCE

(Serves 4)

Hoisin sauce is available in the international aisle of many grocery stores or in Asian foods stores. You can use another sauce in this recipe, such as teriyaki, if you'd like to. Red pepper flakes can be found in most grocery stores in the spice aisle. If you can't find them, use freshly ground pepper. Arrowroot will work instead of cornstarch; however, if you decide to use kuzu instead, you will have to use up to 3 teaspoons.

Boiling water
2 cups broccoli florets, cut into bite-sized pieces
Ice water to stop the cooking process
1 large onion, cut in half and sliced
1-½ teaspoons oil
1 cup sliced carrots
1 cup green beans, tips removed and cut into 1-inch lengths
½ cup water
3-4 Tablespoons hoisin sauce
Generous dash of crushed red pepper flakes
1 teaspoon cornstarch

In a large pot of boiling water, blanch broccoli florets for a few minutes. The florets will be fork-tender and bright green. Rinse in ice water to stop cooking.

In a heavy skillet, sauté onions in oil. Stir and cook until lightly browned. Add carrots and green beans, stir, cover, and cook for a few minutes. In a small bowl, blend ½ cup water, hoisin sauce, and red pepper flakes. Add half to the cooking carrots and green beans. Cover and continue to cook until soft.

Blend cornstarch into the remaining hoisin sauce mixture, then stir the sauce into the onions, carrots, and green beans, along with the broccoli. Continue to stir and cook until the sauce thickens and the broccoli is warm. Serve immediately.

Total calories per serving: 89 Fat: 2 grams
Carbohydrates: 17 grams Protein: 3 grams
Sodium: 216 milligrams Fiber: 4 grams

TORTILLA SOUP

(Serves 4)

Kuzu creates a delicately thickened soup. Use your favorite salsa, any variety. If you don't care for cilantro, use parsley or finely chopped spinach instead.

1 Tablespoon oil
1 onion, chopped
3 cups water
One 15-ounce can diced tomatoes
½ cup salsa, divided
One 15-ounce can red or pinto beans, drained and rinsed
3 Tablespoons kuzu
2 cups baked tortilla chips, crushed
1 large avocado, seeded, peeled, and chopped
1 cup chopped cilantro

Heat a soup pot over medium heat. Add oil and onions and sauté until soft and lightly browned. Add water, tomatoes, ¼ cup salsa, and beans. Bring to a boil, then reduce heat and simmer for approximately 15 minutes. Stir kuzu into remaining salsa and blend into the soup. Cook until thickened, approximately 10 minutes. Place tortilla chips and avocado into four bowls and ladle soup over them. Sprinkle cilantro on top to finish and serve immediately.

Total calories per serving: 322 Fat: 13 grams
Carbohydrates: 47 grams Protein: 10 grams
Sodium: 600 milligrams Fiber: 11 grams

WILD MUSHROOM GRAVY

(Makes eight ¼-cup servings)

I like to use dried porcini mushrooms in this recipe, but you can use any variety of dried mushrooms that pleases your palate. Look for these delicacies in natural foods or specialty stores. If you can't find agave nectar or rice syrup, use a small amount of any mild-flavored sweetener, such as fruit sweetener, frozen apple juice concentrate, or maple syrup.

1-½ cups boiling water
½ cup dried mushrooms
1 Tablespoon oil
1 small onion, chopped
1 cup sliced button mushrooms
1/8 teaspoon garlic powder
1/8 teaspoon thyme or sage
1/8 teaspoon salt
1/8 teaspoon pepper
½ cup soymilk
1-½ teaspoons lemon juice
1 teaspoon agave nectar or rice syrup
2 Tablespoons rice flour

Pour boiling water over dried mushrooms and let them rehydrate for at least 30 minutes. While mushrooms soak, heat a heavy skillet over medium heat. Add oil and onions and sauté until onions are soft. Stir in button mushrooms and continue to cook until mushrooms give up their juices. Mix in garlic powder, thyme or sage, salt, and pepper. Cook for 1 minute. Blend in rehydrated mushrooms, soaking water, soymilk, lemon juice, and agave nectar. Simmer for a few minutes. Sprinkle rice flour over the gravy. Stir until thickened. Add more salt to taste, if desired.

Total calories per serving: 70 Fat: 2 grams
Carbohydrates: 9 grams Protein: 4 grams
Sodium: 44 milligrams Fiber: 2 grams

BUCKWHEAT PEANUT BUTTER CRACKERS

(Makes approximately 150 to 200 1-inch crackers)

Looking for a gluten-free cracker? This is the perfect option. Freeze the dough for later use, or store it wrapped in plastic for up to a week in your refrigerator.

2 cups buckwheat flour
1-½ cups potato starch
¼ teaspoon salt
1 to 1-½ cups hot water
3/4 cup peanut butter

Preheat oven to 350 degrees. Line a baking sheet with parchment paper. In a large bowl, combine flour, potato starch, and salt. Blend well. Combine hot water and peanut butter in a blender or in a separate steep-sided bowl with a hand blender. Add liquid mixture to dry ingredients and mix until a stiff dough is formed. You should be able to gather it up into a ball; if not, add more flour or water to achieve desired consistency.

Cut a section of the dough off and roll it out on a lightly floured surface to a ¼-inch thickness. Cut into 1-inch squares. Gather the remainder up and roll it out again to cut more. Repeat until all of the dough has been used. Bake for 35 to 40 minutes or until hard. It is important to bake until hard, or the crackers may become rubbery.

Note: These crackers are very crisp. If you cut back the potato starch to 1 cup, the crackers will be less brittle.

Total calories per serving: 17 Fat: 1 gram
Carbohydrates: 2 grams Protein: 1 gram
Sodium: 10 milligrams Fiber: <1 gram

WHEAT-FREE CORNBREAD

(Makes one 9-inch pan or 12 servings)

For baking, use an oiled cast iron skillet or line a 9-inch cake pan with parchment paper. The tapioca serves as part flour mixture and part binding ingredient.

1 cup cornmeal
½ cup tapioca flour or potato starch
½ cup barley flour
1 Tablespoon baking powder
½ teaspoon salt
½ cup silken tofu
⅓ cup sugar (Use your favorite vegan variety.)
3/4 cup soymilk
Vegetable oil spray if using a skillet

Preheat oven to 400 degrees.

If using a cast iron skillet, place it into the oven and then combine the cornmeal, flours, baking powder, and salt in a mixing bowl and blend well. In a blender or with a hand blender, combine tofu, sugar, and soymilk. When well-blended, stir mixture into the dry ingredients.

Spray the skillet with oil or line a cake pan with parchment paper. Pour in mixture and bake for approximately 25 minutes. The top will be lightly browned.

Total calories per serving: 97 Fat: 1 gram
Carbohydrates: 21 grams Protein: 2 grams
Sodium: 227 milligrams Fiber: 1 gram

SIMPLE ORANGE JELLED DESSERT

(Serves 6)

This is a basic recipe. You can easily change the fruit juice here or add pieces of chopped fresh fruit.

3 cups orange juice
1 Tablespoon finely chopped orange zest
1 Tablespoon agave nectar
¼ teaspoon salt
3 Tablespoons agar

Place all ingredients in a saucepan. Bring to a boil, reduce to simmer, stir, and cook until agar is dissolved, approximately 3 or 4 minutes. Pour into a non-reactive mold or an 8" x 8" glass pan. It will set in approximately 30 minutes. Cut into squares and serve.

Total calories per serving: 68 Fat: <1 gram
Carbohydrates: 16 grams Protein: 1 gram
Sodium: 102 milligrams Fiber: <1 gram

WHIPPED COCONUT FRUIT SALAD

(Serves 6)

This is a fun, pudding-like dessert that can be made with any kind of fruit concentrate. My favorite is organic raspberry, and I use fresh berries for my seasonal fruit. Pouring a little coconut milk over the top makes it look pretty. I have also made this with apple juice concentrate and drizzled it with a little maple syrup before serving.

3 Tablespoons agar flakes
1 cup frozen juice concentrate
3 cups plus ¼ cup water, divided
2 Tablespoons kuzu
½ cup lite coconut milk
1 cup small pieces of seasonal fruit
¼ cup shredded coconut
4-6 Tablespoons lite coconut milk for topping (optional)

Combine agar, juice concentrate, and 3 cups water in a saucepan. Stir and simmer for 5 minutes or until agar dissolves.

In a small bowl, blend remaining water, kuzu, and coconut milk. Stir until kuzu dissolves, then add this mixture to the agar and juice in the saucepan. Cook until mixture thickens, approximately 5 minutes. Remove from heat. Pour into any size glass pan. Allow mixture to gel in the refrigerator for approximately 2 hours. Scrape the jell from the bowl and use a hand blender to whip. Use an ice cream scoop to transfer into serving dishes. Garnish with fruit and sprinkle with coconut. Pour a little coconut milk over each serving to finish, if desired.

Total calories per serving: 135 Fat: 3 grams
Carbohydrates: 27 grams Protein: <1 gram
Sodium: 21 milligrams Fiber: 1 gram

MOCHA DATE-NUT BARS

(Makes one 8- or 9-inch square pan or 12 servings)

Toast raw buckwheat in a heavy skillet or buy kasha, the toasted variety of buckwheat. Hazelnut butter can be found in natural foods stores. You could easily use almond, cashew, or peanut butter instead of hazelnut butter.

Vegetable oil spray
½ cup arrowroot or tapioca flour
1 cup toasted buckwheat or kasha
1 teaspoon baking powder
3/4 cup hazelnut butter
½ cup maple syrup
6 Tablespoons brewed regular or decaffeinated coffee
1 ounce melted vegan dark chocolate
1-½ teaspoons vanilla
½ heaping cup chopped dates

Preheat oven to 350 degree. Lightly oil baking pan. Mix arrowroot with buckwheat and baking powder. In another bowl, combine hazelnut butter, maple syrup, coffee, chocolate, and vanilla. Mix well. Combine with dry ingredients. Stir in the dates. Spread into prepared baking dish. Bake for 30 minutes. Run a knife around the edges and cut into bars while still warm.

Total calories per serving: 237 Fat: 11 grams
Carbohydrates: 34 grams Protein: 4 grams
Sodium: 46 milligrams Fiber: 3 grams

Debra Daniels-Zeller is a freelance writer and a frequent contributor to Vegetarian Journal. She lives in Washington State.