Arrowroot is a starchy powder extracted from the rhizomes of a tropical plant, and it serves double duty as a versatile kitchen thickener and a gentle ingredient in natural body care products. With a glycemic index as low as 14, it also stands out nutritionally compared to many other starches. Here’s a closer look at everything arrowroot does well.
A Neutral-Tasting Thickener for Sauces and Soups
Arrowroot’s most popular use is thickening liquids. Mixed into sauces, gravies, soups, pie fillings, and puddings, it creates a smooth, glossy finish without adding any flavor of its own. That neutrality makes it especially useful in delicate dishes where cornstarch or wheat flour might muddy the taste.
The powder works by absorbing water and swelling when heated. Arrowroot starch gelatinizes at roughly 75 to 85°C (167 to 185°F), which means it thickens relatively quickly once your liquid approaches a simmer. The result is a clear, silky consistency rather than the opaque, slightly chalky look you get from flour-based roux.
To use it, mix arrowroot powder with room-temperature water at a 1-to-2 ratio (one part arrowroot, two parts water) to form a slurry, then stir that into your hot liquid. For a medium-bodied sauce, about 4½ teaspoons of arrowroot blended with 3 tablespoons of water will thicken one cup of liquid. You can substitute it for cornstarch at a 1:1 ratio in most recipes.
One thing to keep in mind: arrowroot doesn’t hold up well to prolonged high heat or heavy stirring. It’s best added near the end of cooking. It also doesn’t pair well with dairy-heavy sauces, which can turn slimy. For cream-based dishes, cornstarch or flour is usually a better choice.
A Gluten-Free, Grain-Free Alternative
Because arrowroot comes from a tuber rather than a grain, it contains no gluten and no grain proteins. That makes it a go-to thickener and baking ingredient for people with celiac disease, wheat allergies, or anyone following a paleo or grain-free diet. In baking, it’s often blended with other gluten-free flours like almond or coconut flour to improve texture and create a lighter crumb.
Per 100 grams, arrowroot flour contains about 357 calories, 0.3 grams of protein, and 3.4 grams of fiber. It’s not a significant protein source, but its low allergen profile is what gives it an edge over wheat and corn-based thickeners for people with food sensitivities.
Digestive Health and Diarrhea Relief
Arrowroot has a long folk-medicine reputation as a stomach soother, and there’s some clinical support for it. A pilot study of 11 patients with irritable bowel syndrome found that taking 10 mL of arrowroot powder three times daily for one month reduced diarrhea, eased abdominal pain, and even had a longer-term effect on constipation after the treatment period ended. Researchers attributed the benefit to increased fecal bulk, which helps the bowel work more efficiently.
The study was small, so the evidence is preliminary. Still, arrowroot’s blandness and easy digestibility are the reasons it has traditionally been recommended for recovering from stomach illness, particularly for infants and young children transitioning back to solid foods. It’s gentle enough that it rarely causes irritation, which is why you’ll sometimes see it listed in baby food ingredients.
Unusually Low Glycemic Index
One of arrowroot’s more surprising qualities is its glycemic index. Boiled arrowroot has a GI of just 14, which is remarkably low for a starch. For comparison, boiled kidney beans come in around 29, and white bread typically scores above 70. A low GI means the carbohydrates in arrowroot are broken down and absorbed slowly, producing a more gradual rise in blood sugar rather than a sharp spike.
This makes arrowroot an interesting option for people managing blood sugar levels, though it’s worth noting that arrowroot is usually consumed in small quantities as a thickener rather than as a main carbohydrate source. The practical blood sugar impact depends on how much you’re eating in a given meal.
Natural Deodorants and Body Powders
Beyond the kitchen, arrowroot powder is a staple in natural skincare, particularly in homemade and clean-label deodorants, body powders, and dry shampoos. Its fine texture absorbs moisture effectively without blocking sweat glands, which is the key difference between arrowroot-based products and conventional antiperspirants that use aluminum compounds to physically plug pores.
Arrowroot creates a dry, frictionless barrier on the skin that helps prevent the bacterial buildup responsible for body odor. It works well in sweat-prone areas like underarms, thighs, the neck, and back. Because it’s non-toxic and rarely irritates sensitive skin, it’s become a popular replacement for talc in body powders. Some people simply dust plain arrowroot powder onto oily roots as a chemical-free dry shampoo, though it can leave a white cast on darker hair.
Frozen Foods and Make-Ahead Cooking
If you’ve ever frozen a sauce thickened with flour and found it watery and separated after thawing, arrowroot can help. Sauces thickened with arrowroot tend to hold their texture better through freezing and reheating than flour-based ones. The starch gels it forms are more resistant to the breakdown that causes liquid to weep out of frozen foods, a process food scientists call syneresis. Adding small amounts of stabilizers like xanthan gum can improve this freeze-thaw stability even further, but arrowroot on its own already outperforms many common thickeners in this regard.
This property makes arrowroot particularly useful for batch cooking. Soups, fruit sauces, and gravies destined for the freezer will maintain a more appealing consistency when arrowroot is the thickener.
How to Store and Use It
Arrowroot powder keeps well in a cool, dry place in an airtight container, typically for two to three years. It clumps when exposed to moisture, so keep measuring spoons dry before dipping them into the container.
A few practical tips for getting the best results in cooking: always dissolve arrowroot in cold or room-temperature liquid before adding it to a hot dish. Never add the dry powder directly to a hot pot, or it will clump instantly. Stir your slurry in during the last few minutes of cooking and remove the dish from heat once it thickens. Overcooking or reheating an arrowroot-thickened sauce on high heat can cause it to thin out again. For acidic dishes like fruit sauces, arrowroot actually performs better than cornstarch, which can lose its thickening power in the presence of acid.