How can I prevent lumps in sauces or gravy?
Lumps usually form in a gravy or sauce when you dump too much flour or cornstarch into the deglazed pan at once. Another culprit: adding cold broth or stock to the hot pan drippings and flour mixture. For a lump-free sauce or gravy, start by making a smooth paste of the flour (or whatever thickener you use) and water, then briskly whisk the paste into the pan sauce. Increase the heat to medium-high and slowly stir in warmed (but not hot) broth, then whisk to break up any remaining bits of the paste or lumps. A flat whisk is the best tool for the job because the shape allows you to simultaneously scrape up the good stuck-on bits (called fond) and blend the paste into the liquid.
You can also use pureed roasted vegetables that you roast along with the meat as a thickening agent, instead of flour. Puree root veggies (carrots and potatoes work best) in a blender, adding a tablespoon or so of warm broth if the blend is too thick. Add the puree to the pan juices, then add the broth, as usual. If all else fails, you can strain out any stubborn lumps with a mesh strainer.
Gravy is best when it’s served right away, so save this job for the last minute. If you need to make the gravy ahead of time, cover it with plastic wrap. Gravy continues to thicken even after it is removed from the heat, so you will probably need to add a little more warm liquid to the gravy when you reheat it.
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