Here at the CIA, we believe in teaching people how to cook confidently. And while we love sharing our favorite recipes with you, in a perfect world, you wouldn’t need them because you would be busy dinner-freestyling!
But to do that, you need all of the information! So today, let’s talk about a fundamental piece of the puzzle that will hopefully be a lightbulb moment as you navigate your way through your culinary journey.
Lids.
It’s a question we get a lot—lid on or off, and does it matter? Yes, it matters, but in order to know when to cover while you cook, you need to know why we cover at all.
This explanation is admittedly a little bit of an oversimplification, and if you’re a food nerd like us, a deep dive into Harold McGee’s On Food and Cooking will really break it down for you. But when it boils down to it (keep reading to find out why that’s a great choice of words!), most cooking is all about the evaporation of moisture.
As food cooks, the water found within it is drawn to the surface. When a pan is uncovered, the moisture turns to steam, and the steam disappears. When a pan is covered, the steam is trapped in the pan to circulate around the food.
Trapped steam can be helpful. It surrounds the food and cooks it more quickly, and it helps to keep the food from drying out. When we want these results, we should cover the pan.
However, foods only brown when their surface becomes dry, meaning the moisture has evaporated. If the food is surrounded by steam, it will never brown because there is too much moisture present. If you want a golden brown chicken breast or flavorful seared mushroom, moisture is your enemy and your pan should never be covered.
If you’ve ever seen a recipe that calls for ingredients to be sautéed in batches, if necessary, to avoid overcrowding the pan, it is to avoid a similar fate. Ingredients, like mushrooms, need space between each other to allow their moisture to quickly evaporate. If they are too close, the water can escape, and it settles at the bottom of the pan. The mushrooms will steam instead of brown, and while that moisture will eventually evaporate and the mushrooms will eventually brown, by this time, the mushrooms will be soggy and overcooked.
Sometimes we use both strategies in one dish. If you’ve ever cooked pot stickers, you know the routine: raw dumplings are seared in oil until they are browned on the bottom. A small amount of water is added and the pan is covered. The dumplings are steamed until they are cooked through, and then the lid is removed to allow the remaining water to evaporate, further browning the bottom of the dumplings.
This is helpful if you are sautéing a hearty vegetable, like carrots. They might be as brown as you want them to be, but still raw in the center. Cover the carrots and they will cook quickly without too much additional browning.
But what about when a pot is already full of liquid, like when we are braising or making a sauce? Remember that when the lid of the pot is off, even a lightly simmering liquid is evaporating.
As the sauce or braising liquid evaporates, it concentrates the flavors of the sauce. This is called reducing. This often a good thing, but sometimes we unintentionally concentrate flavors we don’t love—like too much salt. Evaporation also thickens some liquids, which can again be a good thing, but it’s possible to overthicken by reduction.
In these cases, if you simply want the liquid in your pan to get hot and for the flavors to meld, then you should cook them with the lid on. If you want the ingredients in your pan to reduce and concentrate in flavor and viscosity, you should cook it with the lid off. Just keep in mind that if you are braising, you might need to add more liquid as you cook to keep your main ingredient covered.
Let’s recap:
Uncovered:
- When we want to evaporate moisture quickly
- Searing/when we want ingredients to brown
- Tender, quick-cooking items
- To reduce, like for a sauce or braising liquid
Covered:
- When we want to trap moisture
- When steaming
- For braising and stewing, to avoid over-reduction of the liquid before the ingredient is fully cooked