Crafting a comforting, home-cooked meal isn’t exactly rocket science, but there are certainly a number of techniques you’ll need to master over time. One of the simplest and most satisfying is learning to make your own gravies and sauces. Most are made with either flour or cornstarch in the form of a roux or slurry.
Cornstarch vs. Flour
The whole question of whether you use cornstarch or flour for gravy is a complicated one. There are some specific reasons for choosing each starch, though at bottom, it mostly comes down to personal preference. A gravy made with cornstarch tends to be lighter than one made with gravy, and it has a beautiful sheen and translucence to it. A gravy made with flour is sturdier and opaque.
Each has its place. Many cooks prefer flour gravies for rich red meats, like pot roast or leg of lamb, but they lean toward cornstarch gravies for chicken or turkey. Technique plays a role, too, because flour gravies are usually made with a roux, while cornstarch gravies are generally made with a slurry.
Roux vs. Slurry
Flour gravies tend to be heavier, in part, because of the roux they’re made from. Making a roux means stirring the flour into a bit of fat, usually the drippings from the roast, so the fat coats the flour and its starch granules. Then, when you add the hot pan juices or broth, the flour disperses evenly before it begins to absorb the water and thicken.
To make a slurry with cornstarch, simply whisk the starch into a small quantity of cold water – or sometimes another liquid if you choose – and then whisk that water and starch mixture into the pan juices or broth. The slurry dilutes as you stir it into the other liquid, distributing the silky cornstarch granules as they begin to thicken.
Making Your Slurry
Making a cornstarch slurry is easy. You’ll need 1 tablespoon of cornstarch for every cup of liquid you’re going to thicken, and you’ll need about 2 tablespoons of cold water to dissolve that tablespoon of cornstarch. If you’re new to gravy-making, it’s not a bad idea to measure the broth or drippings you’re going to use. That way, you’ll know exactly how much cornstarch to add. With experience, you’ll be able to eyeball it and skip the measuring stage.
If you find your gravy is thicker or thinner than you’d like, you can adjust it. You can thin an over-thickened, gummy gravy with a bit of water or broth. In fact, if your pan juices are strongly flavored, you might find the gravy is improved by diluting them a bit. If your gravy is too thin, you can whisk up a smaller amount of slurry and stir it in just a few drops at a time until you reach the right consistency.
A Slurry Isn’t Mandatory
It’s important to remember that just because a specific technique is usually used doesn’t mean you can’t switch things up. If you feel the need, you can certainly make a cornstarch roux instead of a slurry. You might want to do that for a very small batch, for example, rather than dilute the pan juices with the water you’d need to make a slurry. The small amount of fat you use to make your roux can make a richer-tasting gravy as well.
On the other hand, if you want the convenience of a slurry but the heartier mouthfeel of a flour gravy, make a flour slurry. Flour doesn’t thicken as strongly as cornstarch, so you’ll need about 2 tablespoons for every cup of broth or pan juices you use in your gravy.