August 15, 2013

How to make the perfect egg

Today I did an experiment on how you can make the perfect egg with nothing more than a 7 qt crock pot, a thermometer, and a up to a dozen eggs.

This is a follow-on to my perfect eqg quest post, simplified greatly. I wanted to reduce the procedure to more or less cookbook so that someone could get a baseline on what the perfect egg starts to look and taste like so they can experiment from there.

1) Turn on your 7qt crock pot and add 2 liters of hot water from the tap. Add 3 cups of boiling water. Stir and measure the temperature. It should be somewhere around 130F.

2) Put the lid on and allow the water to come up to 155F. This should take about 30 minutes or so.

3) While the crock pot is coming up to temperature, put a dozen eggs into a bowl and fill with hot water from the tap. Every 10 minutes, empty and fill with more hot tap water.

4) When the temperature in the crock pot reaches 155F, put in the dozen eggs, replace the lid, and turn off the crock pot. I also put a couple of tea towels on top of the lid to increase insulation.

5) Set a timer for 25 minutes.

6) After 25 minutes turn the crock pot back on and set the timer for 5 more minutes.

7) After 5 minutes, add about 1.7 liters of boiling water to the crock pot and replace the lid. Set the timer for 5 minutes.

8) After 5 minutes, remove the eggs and place inside a bowl filled with ice water for 5 minutes.

9) Serve as you would poached eggs. I like to put two of them in an ice cream bowl with a little salt and pepper.

What this does is it brings up the yolk of the egg to 150F or so which produces a perfect custard like yolk. The last 5 minutes at a higher temperature cooks the whites just a bit more and keeps them from being runny without becoming rubbery.

I store the eggs in the refrigerator until ready to serve. On serving I empty the contents of two eggs into a small bowl, microwave for about 25 seconds and serve with a bit of salt and pepper.

August 9, 2013

The quest of the perfectly boiled egg

Boiling an egg may be one of the simplest culinary chores, but believe it or not it can also get quite complex. If you're a big fan of scrambled eggs, you probably know that the best ones are made when the eggs come up to temperature slowly and evenly, which means low heat stirred often. The reason for this is because there are a few different proteins in the eggs which congeal at different temperatures.

There are two basic methods employed which are the soft and hard boiled eggs. The soft boiled egg is really just a reduction in time from the time required for the yolks to fully coagulate. The result is the yolks will be less firm than the whites due to the eggs cooking from the outside in. The biggest problem (at least for some) is that the whites tend to get rubbery from overcooking while the yolks are still undercooked. The quest for the perfect tender white and the perfect custard like yolk is never ending.

For centuries cooks have known that the best boiled egg is not boiled at all!

I love eggs and always keep a dozen in the refrigerator. Even though I seek out the best dates from the market when I buy my eggs, often I don't use them prior to their expiration date. Since I hate to throw out food and especially good sources of protein, I am always looking for uses for them prior to expiration. One easy solution is just to hard boil them, which effectively pasteurizes the eggs and extends their shelf life, but I don't particularly care for hard boiled eggs. Soft boiling them is a partial solution, but soft boiled eggs should be eaten right away unless you know for sure you have reached pasteurization temperature and time (more on this later). Sous vide eggs was a very interesting compromise for me. Pasteurization is a function of time AND temperature. So by cooking eggs for a longer time at a lower temperature you not only pasteurized them, but you also got something quite similar to soft boiled eggs. This presented it's own challenge. The egg yolk actually coagulates at lower temperatures than the whites. So in order to get custard like yolks, you were often left with runny whites (kind of the opposite of a soft boiled egg).

The good news is that you don't have to use boiling temperatures at all, and there's just a few things you need for countless experimentation. All you really need is a cooking vessel (I recommend a 7qt crock pot or a cast iron dutch oven), a thermometer, water, and eggs.

1) First a note on pasteurization. If you are reaching pasteurization time and temperatures, you can extend the shelf life of your eggs by a few days. So how do you know if you are there? Well a good rule of thumb is that if the yolk is not runny like a raw egg, even in the center, you have reached pasteurization. While it is possible to reach pasteurization with runny yolks, you know if you are beyond that stage, pasteurization has been achieved. You don't have to get to the firm yolk stage for this to happen. There are many custard like stages that happen prior to the yolk firming. All you are really looking for is that no part of the yolk is as runny as a raw egg.

2) Next a note on egg cracking. Eggs that are close to their expiration date will crack more readily than eggs which are fresh. What I do is prior to cooking I will soak my eggs in hot tap water for about 30 minutes or however longer it takes before I need them, replacing the water every 10 minutes or so. This brings the eggs from refrigerator temperatures to well above room temperature in the middle. If you have a problem with eggs cracking, absent rough handling getting them into the water bath the biggest culprit is temperature shock. The expanding gasses inside the egg can only escape via the egg pores and if they try to escape too quickly, the egg will crack.

3) The basic idea here is that you are going to use a temperature that begins at something less than boiling, then you are going to put the eggs in and turn off the heat. You will then allow the eggs to cook with just the residual heat contained in the water and cooking vessel. By varying the starting temperature, and the time the eggs are in the water bath, you can vary the consistency of both the yolk and the whites. Higher temperatures and faster cooking times will result in whites that are more dense and yolks that are less dense. Lower temperatures and longer cooking times will result in yolks that are more dense and whites that are less dense.

First I will describe a basic method using a 7qt crock pot (which I recommend). A 7qt crock will do a dozen eggs quite nicely. Fill the crock pot half full with a combination of boiling water and tap water until you get to 20F below your target temperature. For instance, if your target temperature is 170F, you will want your water temperature to be 150F. Turn the crock pot on high until your target temperature is reached. This will take about 30 minutes or more, which gives you time to perform the procedure listed in paragraph 2.

When the water in your crock gets to your target temperature, gently put the eggs into the water bath and turn off the crock. Put the lid on and allow to rest for your target time. If you like firm yolks and whites, I suggest going with a target temperature of 170F and a time of 30 minutes. If you like a consistency that is less firm for either the whites or the yolks, vary the two parameters per paragraph 3.

After your target time has been reached, take one of the eggs out and try one. If the eggs are ready, take them out of the water bath and rinse them off in cold water for a few minutes before refrigerating. This will arrest the cooking process.

Edited to add subsequent posts:

Here's another variation from the basic method:
If you follow the link I provided previously, there's a pretty handy chart which shows the coagulation level of the proteins in the white and yolk.

• 144F White: Begins to set, runny [font color="orange"]Yolk[/font]: Liquid
  
• 147F White: Partly set, runny [font color="orange"]Yolk[/font]: Begins to set
  
• 151F White: Largely set, still runny [font color="orange"]Yolk[/font]: Soft solid
  
• 158F White: Tender solid [font color="orange"]Yolk[/font]: Soft solid, waxy
  
• 176F White: Firm [font color="orange"]Yolk[/font]: Firm
  
• 194F White: Rubbery solid [font color="orange"]Yolk[/font]: Crumbly texture
  

The first thing you do is pick a consistency level for your yolk on the right. It will not be possible to get a consistency level for the white to be less than this point on the chart, however you can go the other way. If you want a yolk that is just beginning to set and a tender solid for the white, what you would need to do is hold 147F for a period of time(10 minutes or so), then raise the temperature to 158F.

Depending on your cooking vessel, this will take a bit of experimentation. For a 7 qt crock the temperature will drop about 8-10F when you put a dozen eggs in(provided they are room temperature or higher). So you would heat the water to 157F, put the eggs in, wait about 10 minutes, add some boiling water till the temp gets to 158F and then let the eggs sit in the water bath for about 5 more minutes or so.

Here's a trick regarding temperature measurement:
I remove the knob from the lid for my 7qt crock pot. This gives me a hole to insert my temperature probe. So I can make temperature readings without having to hold the lid off. I record the temperature every 5 minutes so I can make a simple temperature profile in my cooking journal.