What’s the subject about leaving over unpeeled eggs, and then eating them? What if the unpeeled eggs are put in a bag overnight? How does one peel eggs on Shabbos?
The Gemara (Niddah 17) writes that eggs, onions, and garlic, which are peeled and left overnight (without before being mixed with other ingredients) may not be eaten, because an “evil spirit” rests on them.
This halachah is not mentioned by the Rambam or the Shulchan Aruch, perhaps because they reasoned that the ways of ruach ra’ah (the evil spirt) have changed, yet it is mentioned by the Semak (168), by the Peri Chadah (116), and by the Shulchan Aruch Harav (Shemiras Haguf Vehanefesh), and cited by later authorities.
Therefore, if a peeled egg is left overnight, it should be discarded. Placing the eggs in bags does not help, but if some of the peel remains, or if “egg salad” has been prepared by mixing with oil and spices, the egg or egg salad can be left overnight. If the egg is unpeeled, it is fine.
It is permitted to peel an egg on Shabbos, because this is the way in which the egg is eaten. However, one should ensure to peel the egg close to the time of eating it, so that peeling the egg is considered part of the process of eating.