All About Corn Starch

It’s what gives our soups, stews and custards their thick and creamy consistency. And, when made into corn syrup, it’s what sweetens our desserts and drinks. For gluten free eaters it is a go-to thickening agent, as the main component – corn – is naturally gluten free. But is all corn starch you buy in shops fully gluten free?  

Here we take a closer look at this cooking staple to determine the extent to which it is compatible with a gluten free diet and how to make sure your corn starch is always safe for coeliac sufferers. 

Corn starch is a fine, white cooking and baking powder derived from corn grains. It is obtained by separating the starch from the fibre, protein and oil content of corn kernels through a cleaning, washing and grinding process. 

Modified corn starch is simply corn starch that has been changed or altered in some way to enhance its natural properties and make it better suited to a certain culinary purpose. Some purposes of modification include increasing its ability to withstand higher temperatures, lengthening or shortening gelatinisation time and improving the consistency of processed foods. 

Corn is a naturally gluten free grain, and as corn starch is derived purely from the corn kernel itself, corn starch is inherently gluten free too. However, there can be exceptions when it comes to certain commercially produced corn starches. 

Some corn starches are processed by the same equipment and in the same facilities as those used to process other gluten-containing grains and products. This means any corn starch produced in joint facilities is likely to be contaminated with gluten. Therefore, when purchasing corn starch it is important to carefully check the packaging for a certified gluten free label to make sure the corn starch you are buying is fit for gluten free consumption. 

Corn starch is most often used as a thickening agent, giving pie fillings, gravies, sauces, stews, soups and custards (to name a few) their fabulously rich consistency. But it is also used as a stabilizer, an emulsifier and to make corn syrup, and can even be used as a partial substitute for other flours in gluten free bakes. 

Wheat starch and corn starch are both fine white powders that, if certified gluten free, can safely be used in gluten free cooking to thicken sauces, stabilize desserts and emulsify salad dressings. The big difference between them is that corn starch is naturally gluten free, while wheat starch, as it is made from wheat, contains trace levels of gluten.  

As long as the gluten trace level is no more than 20 parts per million – the trace level considered by the world’s foods standards agencies to be safe for people with coeliac disease – then wheat starch is suitable for gluten free eaters and should come with certification on the packet to indicate that. (For example, at Schär, we use certified gluten free wheat starch to make our gluten free croissants à la française deliciously light and flaky.) If you come across any wheat starch that is not certified gluten free, however, steer clear!  

The main benefits of corn starch are related to its culinary functions. It is a much more powerful thickener than flour, meaning that you need to use a lot less of it to get the same or better effect. It is also a safe way (provided you check the packaging) of improving the texture of gluten free cooking – it can be stirred into dough mixtures to make gluten free bakes more tender, beaten into eggs to make omelettes fluffier and slathered over fried chicken (before frying) to increase crispiness. 

An added bonus is that, when stored in the correct conditions, corn starch can last almost indefinitely, thanks to its lack of perishable protein or fat content. 

Corn starch is what makes some of Schär’s best-selling foods so rich, creamy and substantial. And you can rest assured that all our corn starch is certified gluten free; we carry out audits in the facilities of all our corn starch suppliers to make sure we are only using corn starch that has been produced in environments which are fully free from the risk of gluten contamination.  

You will find corn starch adding viscosity to most of the products in our ready to eat range, from our gluten free lasagne to our tiramisù. You will also find it binding together our sweet and savoury snacks, such as our mini muffins and our cereal crackers. And you will even find it propping up our range of gluten free pizzas. 

As we have seen, corn starch is fully compatible with a gluten free diet, as long as you buy corn starch that is guaranteed to be free from any risk of gluten contamination. Although it doesn’t contain much in the way of nutrients, corn starch is a vital ingredient for enhancing the texture and consistency of gluten free foods. And remember, a little goes a long way, so while it may be rich in starchy carbohydrates, you only need stir in a dash to get the desired effect. 

There are many ways in which you can use corn starch in your own gluten free cooking. For inspiration on the different things you can do with it, why not check out our recipes for gluten free sesame chicken, gluten free apple turnovers or chocolate pudding pie, and mix your way to thicker, gooier and richer meals.