Yes, without doubt, if the oil is hot, but not hot enough, this is a real problem and your food will be totally ruined. I have plenty of experiences that my eggs got stuck and my dumplings got burnt when the oil wasn't hot enough or too hot.
But I find when you are familiar with your cookware, it's really not necessary to use any thermometer, but observing, and waiting for the right time to put the food into the oil is good enough. You'll fry your perfect dishes.
But I find when you are familiar with your cookware, it's really not necessary to use any thermometer, but observing, and waiting for the right time to put the food into the oil is good enough. You'll fry your perfect dishes.