The albumen of my hard boiled eggs turned purple. What would cause this and is it ok to consume?
Everything you need to know: Google for "Purple Deviled eggs".
But if you didn't pickle it, then beware.
Pink or iridescent egg white (albumen) indicates spoilage due to Pseudomonas bacteria. Some of these microorganisms—which produce a greenish, fluorescent, water-soluble pigment—are harmful to humans.
Source: United States Department of Agriculture
Is it purple throughout or is there a layer near the yolk that's really more of a gray?
If the latter, it's simply because the eggs were cooked too long or at too high a temperature. It's a reaction between sulfur and iron. Perfectly safe, but try putting the eggs in room temperature water then bringing the water to a boil. Once at the boil, turn off the heat and leave the eggs for 11-13 minutes. You can then remove the eggs and run room temperature water over them to stop the cooking.
My Great Aunt makes a casserole every year, with purple hard boiled eggs. The reason for this is she is using a solid aluminum, from the 40's or 50's, pot to boil the eggs in. I don't know why she doesn't use a different pot, go figure, she knows what it does. No one these days has aluminum cookware so it isn't an issue. Apparently, back in the day, it was a common enough occurrence. That generation generally isn't internet savvy, if you were at a church function and asked this question, chances are, all the greatest generation ladies would immediately answer. In recap, there is nothing wrong with the eggs. They are fine to eat or use in cooking. There is something that goes on between the egg and the aluminum that makes it change colour for some reason. I wish one of the science guys would pick this up and do a show on it and explain. Hope this helps!