Through Thick and Thin….

In the class, “660 Curries” with Raghavan Iyer, rice flour was used to bind the pigeon pea fritters. He explained that rice flour doesn’t require a slurry; it can be used as it is. This surprised me, and started me thinking about thickeners in general. I don’t work with rice flour very often, and know very little about it. I figured that I’m not alone in that. How does one decide to use cornstarch or rice flour? Or arrowroot? Which ones need a slurry? What is a slurry?

First, it helps to understand what each thickener is made of and how it’s used, and then look at appropriate application. There are so many thickeners, that you really could write a book on thickeners alone. For the purpose of basic kitchen use, I’m going to look at a few of the more common ones.

Cornstarch is a so -called “super-thickener”. It is made of starchy granules that attract liquids and expand. However, the expansion only lasts for a short time, and breaks down with high temperatures. It should also be noted that acidic foods decrease the thickening power of cornstarch.
Before adding it to hot foods, make a paste by mixing cornstarch with cold water- this is called a slurry be careful not to overcook as it will begin to break down and thin out. Stir continuously but gently; too much vigorous whisking will cause loss of texture.

Once the cornstarch paste (slurry) has been added, cook over medium heat and bring to a boil for about one minute. Remove from heat. Recipes with cornstarch should not be frozen.

Cornstarch will result in a cloudy sauce or filling (like lemon meringue pie), but creates a nice sheen on pie crusts.

There are many other ways to use cornstarch. Popular shortbread and cake recipes call for replacing some of the flour in the recipes with cornstarch to produce a finer texture. You can also make your own cake flour by replacing some of the flour with cornstarch.

Tapioca starch is made from cassava plant. It is can be used both in desserts and savory recipes. It is essentially flavorless, and is noted for its texture as a thickening agent. It does not require a slurry.

Arrowroot is a white powder extracted from the root of a West Indian plant. It both looks and feels like cornstarch, and is used in a similar manner. It is flavorless. Arrowroot mixtures thicken at a lower temperature than those mixtures made cornstarch. Before adding to hot liquids, mix arrowroot with the cool liquids in the recipe (this is the same slurry that is used for cornstarch). Cook it until the mixture thickens, and remove from heat immediately to prevent mixture from thinning. To substitute arrowroot for cornstarch, use two teaspoons of arrowroot can be substituted for every 1 tablespoon of cornstarch. Arrowroot results in a clear, shimmering gel, like a fruit Jell-O. It can also prevent ice crystals from forming in homemade ice cream.

Wondra is the same as instant flour. It is a low protein, pregelatinized wheat flour to which some malted barley flour has been added. The processing of it results in a fine grained flour that dissolves quickly in either hot or cold liquids, and is most often used to thicken gravies and sauces.

Rice flour is a finely ground powder of rice, used commonly in Indian cooking. It is used as is, without making a slurry.

Hopefully, this short study in thickeners helps clarify the basic types available, how to use them, and where they’re from. Again, this is not an exhaustive explanation- as you can see, it’s quite a thick subject.
-Josie