Typically, I don't eat boiled eggs, but I've had a craving for an egg salad sandwich. Every once in awhile I'll get a craving for foods that are low on my enjoyment list.
It's like my feelings about Spam (the canned meat). About every two years, I have a craving for Spam. Eventually I'll buy a can and fry it up for breakfast. After which, I've met my sodium and Spam quota for another two years.
Being an engineering geek, I started think about the issue of hard-boiled eggs or hard-cooked eggs.
Background, a little long-winded, while I was in college, the math department shared a building with the Home Economics/Food Science department. I remember leaving calculus and diff e.q. classes smelling the food being cooked. Walking through the building, some classroom labs were set up with 6 or 7 kitchen. It all looked fun.
A classmate mentioned that he had taken the class and it was open to anyone. A few years later, I took the "Introduction to Foods" class. The class was a nice diversion from engineering classes, had a high girl to guy ratio, but more importantly we ate what we cook. :-)
One of the lessons involved egg cookery. The instructor discussed that based upon studies, for tender less rubbery eggs, the eggs should be hard-cooked not hard-boiled.
What's the difference?
Hard cooked: The eggs are brought to a boil, taken off the heat and allowed to sit in the hot water before draining and cooling. A better description can be found at the American Egg Board website: AEB: Hard-cooked eggs
Hard boiled - The eggs are boiled the full cooking time before draining and cooling.
As I mentioned earlier, being an engineering geek, I decided to make a science experiment out of my craving. Hard-boiled vs. Hard-cooked eggs.
The eggs I'm using expire March 17th, in two days.
I used 4 eggs that weighed about 56 grams each.
I pierced the eggs at the air sac, at the fat end of the egg.
Note the pin-prick on the two eggs towards to top-right corner.
1. I placed two eggs, one with a pin-prick and one without, into one pot. The other two in another pot.
2. Filled the pots with an ample amount of water - about 1" of water above the eggs.
3. Brought the pots to a boil. I did give the eggs a stir before the water started boiling.
4. For the hard-cooked egg pot, when the water comes to a boil, the pot was taken off the heat, covered and the timer set for 15 minutes.
For the hard-boiled eggs, I let the eggs boil, covered, for 10 minutes.
5. Cooling the eggs. After the allotted time, I dropped the eggs into an ice bath. The eggs with a pin-prick I allowed the eggs to cool completely in the cold water. The other two eggs I just dropped in the ice bath and immediately removed from the water.
What I was trying to show/prove to myself.
1. There is a difference in texture between hard-cooked and hard-boiled.
2. How cooling effects the yolk. The green ring around an egg yolk is due to slow cooling rate.
3. The pin-prick forms a better looking egg.
Top Left Egg: Hard-Cooked with Pin-Prick, completely cooled
Top Right Egg: Hard-Boiled with Pin-Prick, completely cooled
Bottom Left Egg: Hard-Cooked, No Pin-Prick, dunked and taken out
Bottom Right Egg: Hard-Boiled, No Pin-Prick, dunked and taken out
1. All the egg yolks look great - No green ring.
2. The idea of stirring is to center the egg yolks. This seemed to work for all but one of the eggs. I've also heard that spinning the egg on the counter before placing in the water will center the egg yolk.
3. The pin-prick is supposed to allow air to escape from the air sac so the egg has a nice oval shape. The top two eggs do have a slightly rounder shape than the bottom two.
4. Texture - I tasted each of the four eggs. The egg whites all seemed the same. Although, the hard-cooked eggs were very slightly less rubbery, but I just considered the eggs were all the same since the difference was very subtle.
a. Cooking - I don't think there was a big difference between the two methods. Maybe if I was cooking more eggs, but right now I'll consider them the same. I did use older eggs. I wonder if fresher eggs would behave the same.
b. Cooling - There didn't seem to be a big difference with the cooling method. However, I did use the eggs immediately. If I were cooking eggs ahead of time for use later on, I'd still let the eggs cool completely in an ice bath or running water to avoid the green ring around the yolk.
c. Pin-Prick - the pin prick did round the egg a little. If I'm making deviled eggs for a platter, I would still prick the end but use a thicker pin and use eggs that were a little fresher.
Note on egg freshness:
The fresher the egg, the smaller the air sac. This would make for a better presentation for deviled eggs. However, the fresher the eggs the higher the chance the shell will stick to the cooked eggs making peeling very difficult.
Back to why I made boiled eggs - egg salad sandwich.
For the remainder of the eggs, I minced with a fork.
about 2 Tablespoons of Mayonnaise
A little mustard
Served between soft sandwich bread.
The sandwich hit the spot and I answered some lingering questions I had about egg cookery! :-)