What is the difference between simmering covered and uncovered?

Online Answer
Always cover your pot if you're trying to keep the heat in. That means that if you're trying to bring something to a simmer or a boil—a pot of water for cooking pasta or blanching vegetables, a batch of soup, or a sauce—put that lid on to save time and energy.
Related Questions 📌
Remember that raw meat is a breeding ground for bacteria. The best way to protect it is to follow all of the safety recommendations. Do not leave it uncovered as not only can it grow bacteria but it could also potentially share bacteria in the fridge.
Salmon can be cooked either covered or uncovered, but we have found that the salmon will come out extremely tender and perfectly cooked if you cook the salmon in foil.
Do you cover a chicken when roasting? We generally like to roast our chicken uncovered so the skin crisps up and turns an appealing golden brown. If the chicken starts to get too dark before it reaches the proper internal temperature, you can tent a piece of foil over the top to protect the skin from burning.
Cover the pot with a lid. ... Your fork should easily slide through the potato when they're properly cooked.
Because risotto is cooked uncovered on the stovetop, a lot of liquid evaporates. Plan on about three times as much liquid as rice. And that liquid should be stock of some sort.