I always put a lid on the pan when I cook ground meat / hamburgers because it prevents the meat from drying. But some people insist that it also allows food to cook faster because the heat is trapped and reflects off the lid back towards the content of the pan, thus heating both sides simultaneously.
On the face of it, it makes sense but I’m skeptical. Hamburgers only take 10 minutes to cook on medium high, 5 minutes per side. I’m not sure that putting a lid makes any difference for such a short cooking time. And if it really does, the difference must be marginal.
Keeping the lid on really does keep the heat in, and things will cook faster. I can’t quantify it because there are a lot of variables. But the way things cook with the lid on is different than without.
A lot of the heat from the pan bottom is used to heat air. With no lid, the air rises taking heat with it. It also creates steam and water vapor from the food, which also takes heat away with it and dries the food.
A lid prevents the escape of heat from these two mechanisms. However, with the lid on, part of the cooking will be from the steam. When food is cooked by the steam and vapor, it is different from the Maillard reaction that occurs by browning it on the bottom of the pan. A steamed hamburger is not as delicious as one with a nice seared crust.
Conversely, you should always cook rice with the lid on because you want the rice to be steamed, and the lid keeps the heat in.
So forget about the cooking time and focus on what kind of result you want.
It’s an easy thing to test, especially with hamburgers. Next time you’re panfrying some burgers, when you add the cheese, leave one open to the air and cover the other with a metal bowl. After 2 minutes, remove the bowl and observe which one has melted cheese and which one is just beginning to melt at the edges.
The lid allows the air in the pan to get hotter so the food will cook faster. Not much difference in time if something cooks fast, but moisture is trapped also and changes the quality of the food cooking. Often that doesn’t matter either. The bottom of the pan gets hotter also, it’s not dissipating heat as rapidly, so something that you’re cooking at just the right temperature with the lid off might get scorched with the lid on.
As stated above, I would not cook hamburgers or anything I want to brown with the lid on. (Well, not completely. When I caramelize onions, I can finish them in about 10-12 minutes by starting them with the lid on and then on full heat for the first four or five minutes to get them to sweat and cook and then boil off the water to allow them to brown.)
As CookingWithGas says, my decision to cook covered or uncovered most has to do with the results. I have not noticed covering a pan keeping meat itself any moister than an uncovered pan.
I 'm not sure why this hasn’t been mentioned (i.e., perhaps to some it’s too obvious), but stuff gets hotter quickly because of the higher air (steam) pressure when the lid is down. So boiling water for whatever is quicker–not boiling water away–with the lid on. Time- to- boil is longer in Denver than in NYC, where Newton supplies the lid for everybody.
Also, steam (water) is a far more efficient conductor of heat than air. For example, lobsters die just as fast, if not quicker, in a few inches of boiling water in a covered pot, compared with a full boiling pot.
Well, meat does seem less dry when I use a lid but perhaps it’s just me. It’s difficult to quantify, anyway.
To be clear, heat being trapped by the lid and allowing food to cook more quickly makes sense but my skepticism had to do with the short cooking time: 10 minutes. I’m not sure it really makes a difference in this case.
To me, the main advantage of putting the lid on is to save expensive energy. It’s bad enough that heat is going up the outside of the pan, without having it escape from the top as well. There is also a side benefit where the kitchen doesn’t get so steamed up.
It’s important to regulate the gas and use as big a pan as practicable. Once the water in a pan reaches 100° C it will not get any hotter unless the lid is a really tight fit, which I think would be dangerous anyway. So, as soon as it boils, turn the gas right down.
Many years ago (30+?) I bought a set of SS pans with glass lids. One of the best things I ever bought for my kitchen.
Cooking with a lid on does several things. As others have noted, it retains the heat in pan. If you’re cooking something with a lot of water, it also causes the pan to fill with steam. So any parts of the food that aren’t in contact with the pan or with hot liquid in the pan will be exposed to the steam and will cook faster.
However, this is not always a good thing. If you’re sautéing or browning, for example, keeping the pan covered keeps the temperature close to 212 F, the temperature of boiling water. The Maillard reaction requires much higher temperatures, over 280 F. So meat won’t brown properly if there’s water or steam keeping the temperature below that point.
It may be less dry, as the liquid is not being allowed to boil off into the atmosphere. By browning first and covering to cook, you are, in effect, braising the burger. I don’t know how thick your burgers are, but ten minutes seems like a long time to me.
I make up burgers 3 to a pound. They’ll be over an inch thick, after browning both sides for about 5 minutes I’ll drop the heat and let them go for about 5 more minutes for medium. Pre-pressed patties can certainly be done in under 10 minutes though.
Moistness of meat has no relation to its surrounding environment and is entirely about cooking temperature and time. Drop a tenderloin into boiling water for an hour and it will be dry as chalk, despite being submerged the entire time.
Most of the heat in cooking is used evaporating water in one way or another. Putting a lid on isn’t about “reflecting heat” since there’s very little radiative heat to reflect. Instead, it’s about trapping the evaporated steam and keeping it inside the pot.
Cooking ground meats with the cover on is a poor technique. The interior of the meat gets too hot and is dryer than if you cooked it uncovered. At the same time, the exterior of the meat doesn’t get hot enough and you don’t get any browning.
When it comes to browning, I used to always keep the lid off the entire time I cook.
One of the things I’ve learned in just the last couple of years is that I prefer to start browning with the lid on, and then leave it off only after the first flip. My experience is that the food-to-pan contact on the bottom surface means that it browns up just fine even with the lid on. However, keeping the lid on after the first flip means you’re softening the crusty brown surface you just worked so hard to create, so I generally finish the second side without the lid. This works especially well with hash browns, steaks and burgers. I get a faster, more even cook and all surfaces end up browned perfectly.
You need the lid on if you want some good steamed hams!
Seriously though, if I’m cooking meat like a burger or pork or a steak I leave the lid off so it can brown, like others have said. The lid only goes on to melt cheese. (I love melting bleu cheese on a steak!)
If boiling stuff or sautéing vegetables the lid stays on the whole time because it’s so much faster.