What is cornstarch?
The short version is that cornstarch is a patented product made from finely powdered endosperm (tee hee) of corn kernels. It serves mainly as a thickener and a binder in both cooking and baking, regardless of type.
How is cornstarch made? Now, the process of producing cornstarch begins with soaking the corn in hot water for a period of two days. Germs are separated from the endosperm, and while soaking, each of the components gets ground. The starch gets separated from the steeping liquid along with the remaining cereal germ and corn gluten; this is primarily done in centrifuges, as well as hydrocyclones. The starch is then subjected to different conditions (temperature, pH, and the presence of other chemical substances) to bring about a reaction. This in turn forms a corn starch with certain properties which are very useful for the culinary works on hand.
As per GMI Research, the GCC Corn Starch Market is estimated to grow at a robust CAGR during the forecast period till 2032.
Important functions of cornstarch in baking
As a thickening agent
Cornstarch can be incorporated as a thickener to a range of mixtures, from gravies to pudding pie fillings, to dessert custards, or cake fillings. While flour is a more commonly used thickening agent, per ounce it has less power than cornstarch. Plus, it is increasingly used on account of being gluten-free, which allows the baking of gluten-free pie fillings and custards.
This is what happens when we add cornstarch to the mixture. The heat in the mixture causes the starch to bind with water molecules present, and the starch begins to swell as it absorbs more liquid.
Once you reach 203 degrees F, the starch at this point will be approximately 10 times its powder form. However, this expansion is not limitless. You can augment sauces or mixtures with cornstarch and bring it closer to a boil, just be sure not to boil it, and do not stir too aggressively. The starch will begin to deflate, and in doing so, will eliminate the entire point of adding it to your mixture.
While the cornstarch will thicken as it heats, it will also thicken as it cools. This is beneficial for further solidifying desserts, such as the filling of Lemon meringue pie. This will also not impart the cloudy color that flour would tend to create.
Along with the thickeners sauces and mixtures, cornstarch may also be used in baking cookies or cakes. It is stated that the addition of cornstarch with flour can help "soften" the harsh proteins of the flour, yielding a more tender baked good. In my own personal experience, I can vouch for this statement. A recipe such as shortbread which employs part flour and part cornstarch yields a cookie with the perfect crumb: crumbly, and yet not fall-apart. It is tender and delicate, but in a way that the cookie still holds its shape.
Cornstarch as an anti-caking agent.
What sets apart confectioners’ sugar from granulated sugar? Other than the texture—confectioners’ sugar is more finely ground—there is also the fact that confectioners’ sugar is blended with a little cornstarch. In this case, the starch performs the function of an anti-caking agent by preventing the sugar granules from clumping together.
Cornstarch is not only used to protect the sugar from moisture decomposition. If you buy shredded cheese from the supermarket then the chances are there is cornstarch in the mix. This is to prevent the moisture and condensation from making the cheese slimy. The only problem with cheese is that the starch tends to turn brown faster than the cheese on the application of heat. This can give a false indication of doneness.
