What causes the green ring around hard-boiled eggs?
. Use eggs that are five to seven days old, because they peel more easily than very fresh eggs.
. Add a little vinegar or a pinch of salt to the water, because it can help prevent cracking.
. Store unpeeled boiled eggs in the refrigerator for up to one week. Once peeled, they should be eaten within two to three days.
How to Enjoy Them

Hard-boiled eggs are versatile and nutritious. You can try them sliced over salads, mashed into deviled eggs, grated on top of avocado toast, chopped into potato salad, or simply sprinkled with a bit of salt and pepper.
In the end, perfect boiled eggs come down to two essential steps. Avoid overcooking, and cool them rapidly. Once you master this simple routine, you can say goodbye to green rings and enjoy smooth, bright yolks every time.
