http://www.thekitchn.com/how-to-make-on ... er-e-81574
See this comment for the best result:
I dye my eggs with onion skins, but I use a different method. I wrap raw eggs with onion skins softened in warm water. I make sure the entire egg is covered, then I wrap in cheese cloth and tie off with twine to make sure the skins stay on they eggs. Then I put the eggs in water to cover with a couple Tablespoons of vinegar. I bring the pan to a boil, turn off the heat, cover and let sit 15 minutes. The eggs turn out mottled and very pretty and they are perfectly cooked. No gray rings around the yolks.
Rewriting this recipe:
4 1/2 cups water in stainless steel saucepan
skins from 10 onions - brown and/or red (or gather from supermarket and save during the year)
3 tablespoons white vinegar
Bring water, vinegar, and onion skins to boil; cover; simmer for 30 minutes; cool to room temperature; strain.
12 medium eggs at room temperature - cleaned beforehand
extra onion skins
cheese cloth
string or thread
Wrap each egg in damp onion skin and cheese cloth to hold in place.
Tie with string; place in stainless steel pot in single layer.
Bring pot with eggs to a boil; cover and turn off heat; let sit in the covered pot for 15 minutes.
This is where the recipe is not clear. Thus, it is important to try this recipe beforehand.
Does one let the eggs cool and dry before removing the cheese cloth/onion skin wrap?
Won't the onion skins stick to the shells?
I would suggest:
Remove the eggs from the pot with a slotted spoon.
Let cool for a few minutes so that the eggs can be handled safely.
Carefully remove the wet cheese cloth and onion skins.
Dry on a rack, and when cool enough to handle, gently brush with extra virgin olive oil for a luscious shine.
Refrigerate.
Please do share your successes or struggles.
Thanks.
In my experience:
I have always used the red onion skins, while others have used brown onion skins.
Brown eggs tend to give a better result with a deeper red whereas white eggs tend to look a pale pink.
While drying eggs on the rack, some of the dye will pool under the eggs. This will leave spots on the eggs.
While the eggs are still warm, reposition eggs to a cleaner area the rack so that they can dry properly.
However, be careful as the liquid dye can run down the egg as it is turned creating more problems.
Eggs must be completely dry before brushing them with olive oil, with no drops of liquid dye from the rack.