Why not cover the pot?
I have noticed some foods, such as quick-prepare ravioli, specifically state not to cover the pot when warming them. Why should the pot not be covered?
I am especially interested in knowing when I can break this rule. Specifically, we heat food on an underpowered electric stove. Covering the pot of water seems likely to raise the temperature of the water, which the directions for the ravioli state should be boiling. Should I leave the pot uncovered as the directions state, or should I cover the pot to raise the temperature of the water that extra little bit closer towards boiling?
Best Answer
By quick-prepare ravioli, you mean without sauce, right?
It's fine to (and you should) cover the pot to bring the water to a boil. Incidentally, it's best to start with cold water from the tap, hot tap water will likely be more contaminated, possibly with lead. Once the water is boiling, add the salt, then the pasta. Adding the pasta will bring down the temperature of the water, so you can briefly put the lid back on to more quickly bring the water back up to the boil.
Once the water is boiling again, it's recommended that you keep it uncovered because pasta water is very prone to foaming up and boiling over. It's a royal pain when that happens, so think before covering pasta while it is boiling. If your pot is big enough and you watch carefully, you can save some energy by cooking with the lid on, just be careful because boil-overs happen quickly. Obviously, it's good to have a stockpot with a glass lid for that.
EDIT: Now that I've covered the conventional wisdom, I'd also encourage you to read this: A to Pasta: is simmering equivalent to roiling boil?, especially the Serious Eats link. I admit, I haven't done it (set in my ways, I suppose), but considering your set-up, you might find the method works better for you.
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Does covering a pot make it reduce?
Cooking a soup, stew, or sauce uncovered allows water to evaporate, so if your goal is to reduce a sauce or thicken a soup, skip the lid. The longer you cook your dish, the more water that will evaporate and the thicker the liquid becomes\u2014that means the flavors become more concentrated, too.Why do we cover pots when cooking?
Cooking with the lid will generate and trap more heat, while a lidless method provides gentler cooking that allows more liquid to evaporate. If you're trying to speed up the process or want to keep every drop of liquid in your pot, cook with the lid on. For a slow simmer or a reduced sauce, go uncovered.Why should we not cover the pot once the pasta were added?
It's okay to put a lid on the pot while you are waiting for the water to boil. However, after it starts to boil and you add the pasta to the water, you should remove the lid to prevent the water from bubbling over. How do you know when the pasta is cooked? Many pasta packages will include a recommended cooking time.Does a covered pot boil faster?
A covered pot boils faster than an uncovered one because the cooling presence of the room's atmosphere is greatly diminished. Once the liquid comes to a boil, the options widen. With placement of the lid, you are attempting to juggle the competing considerations of boil-over, sufficient heat and evaporation.Brass Against - The Pot (Tool Cover) ft. Sophia Urista
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Answer 2
While not relevant to ravioli, many other foods will have a different outcome simply because of the amount of water remaining in the food - removing the lid will result in higher evaporation but keeping the lid will keep the moisture inside, "steaming" the food from above.
Depending on the recipe it may easily be that one or the other is the desired result, and the opposite way produces unwanted results.
Answer 3
They probably recommend cooking uncovered because pasta water easily boils over: particles of starch come off the pasta and form a foam. However, this foam can be very much reduced by adding a small amount of oil to the water – say about a teaspoon. As long as you watch it carefully, you can then put the lid back on (maybe crack it open slightly) and turn the heat down to the minimum level that maintains a boil. But do watch carefully as it might still boil over.
Many people add a little oil to their pasta water, usually claiming that it stops the pasta sticking together. Indeed, I've seen a Michelin-starred chef make exactly that claim on YouTube. However, oil hates water so it doesn't stick to or get absorbed by the wet pasta while it's cooking, which means it can't reduce sticking. It's actually there to reduce foaming.
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Lachlan Ross, Charlotte May, Artem Mizyuk, Max Vakhtbovych