If you’ve ever poured concrete or made a house of mud, you’ve worked with a slurry. In the culinary world, too, we are at times required to concoct a slurry, and we do it for the same reason as those others: To make something thicker and bind it together.
A slurry is just a mixture of liquid (usually water) and “insoluble” matter, according to the Merriam-Webster. When it comes to cooking, the slurry most often utilized is one consisting of cornstarch and water, such as the one we used recently in making cheese fondue.
In that case, we used the slurry to thicken the mixture of cheese and wine so it became one big, unified, melting pot of joy.
But there is protocol to making a slurry, and just as it takes liquid combined with cement to make concrete, we need both a liquid and a powder (i.e., cornstarch) to make a slurry in the kitchen.
If we just dumped cornstarch into a recipe by itself, the stuff would clump up and not do a very good job of thickening whatever you’re trying to thicken. But by first mixing the cornstarch in water and making a slurry, the solution happily combines with the recipe and, due to the heat, thickens and binds. The process is done at the tail end of cooking, because if it cooks too long, the whole thickening process can fall apart.
Tip: When making a cornstarch slurry, make sure the water or whatever liquid you’re using is cold. About 1 tablespoon of cornstarch will thicken 2 cups of the recipe you’re mixing it into, such as a soup, stew, etc.
Do it: To make a slurry to thicken about 2 cups of soup (16 ounces), mix 1 tablespoon of cornstarch with an ounce or two of cold water and mix well. When you’re ready to finish and thicken your recipe, pour the slurry into it, simmer for about 5 minutes, and voila! — whatever you’re making should thicken right up and be ready to serve.
Source: iwanttocook.com (defunct blog)
