Long before I ever made a pot of gravy, I'd been convinced of its difficulty. After all, Heinz had hammered my young brain with the idea that lumpy gravy is pretty much unavoidable.
This, it turns out, is a lie. Gravy is easy to make. There's almost nothing to it, and what little there is, even a turkey could do it—if the turkey weren't dead and in the oven.
Here's the main thing you need to know: Don't want lumps in your gravy? Don't dump dry flour, cornstarch, or any other starch directly into the pot. Boom, done; problem solved.
That said, there are a few other small problems you might encounter when making gravy, so we'll help you troubleshoot them here and in the video above. Read on to see just how easy it is.
How to Troubleshoot Gravy
What Is Gravy?
Gravy is a sauce made by thickening meat-based stocks and/or the drippings from roasts with a roux made from flour and some kind of fat (often butter, though you could use oil or the fat collected from the roast itself).
If you're a student of French cooking, this description may have just turned on a lightbulb above your head. Isn't that the same thing as a velouté, one of the five mother sauces of classic French cooking? Indeed it is, albeit a darker, richer one—velouté is traditionally made by thickening a light stock, such as white chicken stock or fish stock made with un-roasted bones, with a roux. Gravy, on the other hand, includes the darker drippings of a roast.
If you didn't make this connection, then, well, surprise! Your all-American Thanksgiving is hella French.
How Is Gravy Made?
The basic process goes like this: Make a roux by cooking a paste of flour and a fat (like butter), stirring until the raw smell of the flour has mostly cooked off but the mixture has yet to darken.
Then, while whisking constantly, drizzle in hot stock (this can be white or brown chicken stock, turkey stock, or beef stock), beating the mixture well between additions to ensure it stays silky, smooth, and lump-free the whole time. It'll thicken up after a few minutes of simmering, once the flour granules have had a chance to hydrate and swell. This is exactly the same process you'd use to make a classic white sauce.
At this point, you can add the degreased drippings from a roast. (Full disclosure: Sometimes I don't bother degreasing and instead make a really fatty gravy on purpose, and no, I am not at all sorry about this.) You can also add seasonings, like salt and pepper, herbs, chopped-up giblets from the bird, and umami boosters, such as soy sauce or fish sauce.
So you made your gravy, you followed all the instructions, and it came out too thin. What gives? And what now?
How to Fix Gravy That's Too Thin
Your ratio of flour to liquid is a little light on the flour, and you need to remedy that. You have some choices for doing this.
Your first option is to reduce the gravy down by simmering it until enough excess water has cooked off, thickening the gravy in the process. This works well, but has a few downsides. First, it takes time, which you may not have. Second, it reduces the total amount of gravy you'll end up with, and if you only have just enough, you probably don't want to lose that volume. Third, if you've already seasoned your gravy with salt, it will only grow saltier as the water cooks off and the salt concentrates.
Add More Flour
Another option is to add more flour, but you have to be careful about how you do that. If you just dump dry flour into the pot, it'll form stubborn lumps. Instead, you need to make a paste of roughly equal parts flour and softened butter, mashing them together until completely smooth, then whisk this paste into the gravy a tablespoon or two at a time, until the gravy has thickened appropriately. This mixture is called beurre manié in French, and it consists of the same elements used to make the roux, but you're adding them at the end rather than the beginning. It won't form lumps because the flour is fully mixed with the fat, denying the starchy granules a chance to clump up when they hit the liquid.
Add Cornstarch or Arrowroot
You can just as easily thicken the gravy further with another starch, like cornstarch or arrowroot. If you do, you'll once again want to avoid adding the dry starch directly to the gravy, as it can form lumps just like flour. Instead, make a slurry by mixing a tablespoon or two of the starch with just enough gravy to form a thin paste, stirring well to get the slurry smooth and lump-free before whisking it into the gravy. If, after allowing it to simmer for several minutes, you still need to thicken the gravy further, just make more slurry and repeat.
Use Wondra Flour
You can also use a flour product sold under the brand name Wondra. It's a refined flour that is lump-resistant, meaning you can whisk it into your gravy without making a beurre manié or slurry.
How to Fix Gravy That's Too Thick
If your gravy is too thick, that just means it contains a bit too much flour. Thin it with additional stock; you could use water instead, but then you'd be watering down the flavor.
How to Fix Lumpy Gravy
Oh, lumpy gravy, what a manufactured problem you are! If you follow my advice above, you won't have lumps, ever. If, for some reason, you do have lumps, all is not lost. You can either strain out the lumps by passing the gravy through a fine-mesh strainer, or you can break up the lumps with a blender. If you use a countertop blender, make sure to open the blender lid's pour spout, cover it with a clean towel, then start the blender at its lowest speed and only gradually increase it. If you just close the lid and turn the blender to high while the jar is filled with a hot liquid like gravy, a violent eruption can spray gravy all over your ceiling.
How to Fix Salty Gravy
Oops, you just added too much salt to the gravy. Maybe it'll be okay if everything else on the plate is bland, but otherwise, you have a problem. A lot of people recommend simmering potato chunks in the sauce, claiming they'll soak up the salt. This has never worked well for me: It can take hours for the potatoes to take on a noticeable amount of salt.
Easier is just to make a quick second pot of gravy by preparing a roux and adding stock to it. Add this unseasoned gravy to your overly salty one; the additional volume should help even things out.
How to Fix Greasy or Broken Gravy
To prevent a gravy from seeming greasy, avoid adding unnecessary fat to it. Aside from the fat used to cook the roux, any rendered fat from the roast should be poured off before you deglaze the roasting pan to collect the drippings and add them to the pot.
As long as the sauce isn't overloaded with fat, it shouldn't be at much risk of breaking. But if it does, you can bring it back together by working in more starch (as described above in the section on thickening a too-thin gravy) or by using a blender to return it to an emulsion.
A broken sauce is inarguably a problem, but here's where I'll out myself as a lover of greasy gravy. The greasiest gravy I ever made had every last drop of rendered turkey fat cooked into it, and it got more compliments from diners than any other gravy I've ever made. So...maybe that's not a problem that really needs fixing.