3. Keep the heat at a high temperature in order to get that crunchy taste once the sprouts are finished roasting.
There is no need to lower the temperature. They won’t burn if they are set at the correct temperature. By opening and closing the oven it can cause the temperature to lower and it’ll take longer for the sprouts to roast.
The temperature will have to get back to the correct temperature in order to continue roasting. Another reason you will want to set the oven at a high temperature is that the sprouts will turn golden faster. If you are short on time this is the dish to prepare and cook.
If you have plenty of time on your hands and you want to roast the sprouts on a lower temperature that is okay, but they will take longer to roast. The sprouts will eventually get that golden color, but it will take much longer.