Cornstarch is a fine, flour-like powder made from the starchy endosperm of dried corn kernels. The endosperm is the part of a seed that sits underneath the bran and acts as a food store for the germ, which is the part that eventually grows into a new plant. Because cornstarch contains no protein, it’s considered gluten-free despite being made from corn.
Developed in 1842, cornstarch was originally used to starch laundry, but nowadays, it is more commonly used in food and in the kitchen. Starch absorbs water well when heated, so it's often used to thicken sauces, gravies, stews, pie fillings and puddings without altering their taste.
If cornstarch is a mainstay in your kitchen, you're bound to run out of it quickly. But worry not. We have come to the rescue with a list of the best cornstarch substitutes to use in a pinch for all your thickening needs. In the same way as cornstarch, these substitutes should be mixed with cold or hot liquid to make a slurry before adding to your recipe.
All-purpose flour contains half the thickening power of cornstarch, so you will need more of it to achieve the same result. As a general rule, it is recommended that you use twice as much white flour as cornstarch for thickening purposes, so, for every tablespoon of cornstarch required, you'll need to substitute two tablespoons of all-purpose flour. It won't produce the same glossy shine as cornstarch, but it will do the job in a pinch.
When using wheat flour to thicken a recipe, mix it first with cold water to form a paste – this step will prevent it from sticking together and clumping. When using wheat flour as a replacement for cornstarch, keep in mind that it contains gluten, making it unsuitable for people with gluten sensitivities or intolerance.
Arrowroot powder is a starchy flour made from the roots of the Maranta genus of plants, found in tropical regions, and is commonly used as gluten-free flour, so it’s suitable for people who don’t eat gluten. As it thickens the same way as cornstarch, it does not need to be adjusted in amount and is ideal for thickening soups, stews and sauces. One tablespoon of arrowroot powder can be substituted for one tablespoon of cornstarch.
Arrowroot contains more fibre than cornstarch, and it also forms a clear gel when mixed with water, so it’s great for thickening clear liquids. There is one downside to arrowroot: it does not reheat or hold well, so you should use it in dishes you plan to serve immediately.
Potato starch is another substitute for cornstarch. It's made by crushing potatoes in order to release their starch, then drying them to make a powder. It has very few calories, so it's an excellent choice if you want to make a leaner dish. Potato starch also has the same thickening power as cornstarch, so you don't have to change the measurement – if your recipe calls for 1 tablespoon of cornstarch, replace it with 1 tablespoon of potato starch.
Like arrowroot, potato starch is a strong thickener, but it doesn't last long after cooking, so you'll want to eat whatever you're cooking right away. Although it thickens well, it may lose its thickening power if overheated, so it is best to add it at the very end of the cooking process. It tastes bland, so it won't overpower your recipes.
Tapioca starch is a flavourless ingredient extracted from cassava, a root vegetable found throughout South America. It's made by grinding cassava roots to a pulp and filtering out their starch-rich liquid, then dried into tapioca flour. It's particularly suitable for people with diabetes because of its low glycemic index. As it doesn't have the thickening power of cornstarch, you will have to double the amount – for every tablespoon of cornstarch required, you'll need to use two tablespoons of tapioca starch.
Rice flour is made by grinding rice finely. Naturally gluten-free, it is favoured among people with gluten intolerance as a substitute for regular wheat flour. It is also prevalent in many Asian countries, where it is often used to make desserts, rice noodles, or soups. Rice flour can be used in many recipes in place of cornstarch. It has half the thickening power of cornstarch, so you will need to double the amount added: two tablespoons of rice flour for every one tablespoon of cornstarch called for.
Until recently, flax was mainly used for animal feed, but it has become more common in human diets as we have learned more about food science. Flaxseed is highly nutritious and can be used as a grain alternative in coeliac and paleo diets, and as a vegan alternative to eggs. It can also be ground into flour for use in gluten-free baking.
Ground flaxseeds are very absorbent and they form a jelly when mixed with water.
Flax tends to have a gritty consistency, while cornstarch is smooth. To thicken a dish, you can substitute cornstarch by mixing 1 tablespoon of ground flaxseeds with 4 tablespoons of water – this should replace about 2 tablespoons of cornstarch.
Glucomannan is a powdered soluble fibre obtained from the roots of the konjac plant. It forms a thick, colourless, odourless gel when mixed with hot water. As glucomannan is pure fibre, it has no calories or carbs, making it an excellent substitute for cornstarch for those following a low-carb diet.
Glucomannan has a much stronger thickening effect than cornstarch, so you need less of it – about 1/4 teaspoon of glucomannan for every 2 teaspoons of cornstarch. As it thickens at relatively low temperatures, combine it with a bit of cold water before you pour it into your food to prevent it from clumping together when it meets hot liquid.
Psyllium husk is another plant-based soluble fibre used as a thickener. Like glucomannan, it contains very few carbohydrates and a lot of soluble fibre.
Adding a half-teaspoon at a time will be enough to thicken a recipe.
Xanthan gum is a vegetable gum produced through the fermentation of sugar with a bacteria called Xanthomonas campestris. The result is a gel, which is then dried and made into a powder used in cooking. The amount of xanthan gum needed to thicken a liquid can be very small. It can cause digestive problems in large quantities, though you are unlikely to consume much of it as a thickener. You should add a small amount of xanthan gum at a time – too much will make the mixture slimy.
Guar gum is also a vegetable gum made from a legume called guar beans. Beans are stripped of their outer husks, and their starchy endosperm is collected, dried, and then ground into a powder. It’s low in calories and rich in soluble fibre, which makes it a good thickener and, like xanthan gum, a strong one. Try a small amount at first — about 1/4 teaspoon — and build up gradually to the consistency you prefer.
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