how does salt affect eggs in cooking: I’ve had enough! gotta test it myself!

IMG_5632_cc

I know I am way in over my head when it comes to food science, but I will give it my best shot here, what do I have to lose? 4 eggs? that’s worth the risk.

After having eaten possibly one zillions eggs in my lifetime (actual number) I have finally stopped and taken a look at one of those kitchen controversies, to salt or not to salt eggs…before cooking them. I hear Julia and Jacques have tested this, I hear they both disagree. I hear Ramsey is all about salting after cooking them, makes them retain that fluffiness he says, Heston salts his eggs before they go in the sous vide bath. Maybe you know of more examples, but this egg thing does seem to be a common subject of debate out there. It probably doesn’t matter which way you go as long as you understand what salt does to eggs and what effect you are looking for in the end. I personally thought salt didn’t really have a big effect on eggs, but boy was I wrong. Let me show you what I found  on my latest test:  

IMG_5582_cc

For my test I wanted to make sure that I was dealing with as few variables as possible. I wanted to judge salt’s effect on eggs while being cooked. I used my immersion circulator to ensure the cooking conditions were the same but this experiment could be easily repeated by just cooking the two samples on the same pan and using egg cooking rings. Here is what I ended up doing:

1. Crack some eggs, label a couple of  baggies, and measure egg’s weight! 

I used 4 eggs, whipped them together until yolks and whites were nicely mixed, about 2 minutes. Then used my scale to measure the final weight of the eggs so I could divide them in 2 equal parts.

IMG_5571_cc

IMG_5584_cc

2. Whip!!! then divide the weight by 2 and fill 2 baggies for vacuum sealing!

Mix all those eggs together, we want a homogeneous mix to make the test a bit more reliable. Wouldn’t want any differences in the individual eggs ruin my night!

IMG_5587_cc

3. Add some salt to one of the baggies and label accordingly

Added about a teaspoon of kosher salt to one of the baggies. And shook the baggie for a bit to incorporate the salt into the eggs.

IMG_5589_cc

4. Vacuum seal baggies and let rest in the fridge for about an hour,preheat water bath

The first thing that became obvious was a change in the color of the eggs
, at first thought it was due to differences in vacuum, maybe one of the baggies had lost more air, had less bubbles and therefore looked more translucent… so tried it again. Same deal, salt was doing something to my eggs!

baggie with salt: deeper yellow,clearer, more translucent
baggie no salt: milkier color, less saturated, less translucent

IMG_5601_cc

IMG_5597_cc

 

5. cook at 75 °C –  167°F for 15-20 mins

After resting the baggies in the fridge for about an hour (I wanted to make sure that if salt had an effect on texture, the eggs spend enough time with the salt to emphasize this more) the went in the water bath for about 20 mins, making sure that the entire baggies where under water. Wouldn’t want any raw eggs for the tasting part.

IMG_5608_cc

6. taste and draw conclusions on a full belly

After cooking, the color difference became a bit less noticeable but it was still there. I think had I used more eggs, the difference in color would have been stronger. But the difference in texture was remarkably different to my surprise:

eggs with salt: softer, more tender texture
eggs no salt: rubbery, less interesting

IMG_5609_cc

IMG_5610_cc

Conclusions:

I would love to hear your opinion on this subject. I have to admit that before this test I had no idea why or how using salt would affect the texture of cooked eggs. I’m not gonna waste my time or yours pretending that I know exactly why (the chemistry behind it) this happened. Instead I did some reading after the test, and I am going to quote Mr Harold McGee, who is quite possibly the most reputable food scientist in the cooking arena today. If you haven’t read his book On Food and Cooking The Science and Lore of the Kitchen, and you are interested in the science of cooking, there’s no better book out there (You could include also the Modernist Cuisine collection of books, but often they too quote Harold McGee). Anyways, here’s what I read in a chapter dedicated to the all mighty egg:

On color:

“Add a pinch of salt to a yolk (as you do when making mayonnaise) and you’ll see the yolk becomes simultaneously clearer and thicker. Salt breaks apart the light-deflecting sub-spheres into components that are too small to deflect light – and so the yolk clears up”

On texture:

“There is no truth to the common saying that acidity and salt “toughen” egg proteins. Acids and salt do pretty much the same thing to eggs proteins. They get the proteins together sooner, but they don’t let them get as close together. That is, acids and salt make eggs thicken and coagulate at a lower cooking temperature, but actually produce a more tender texture.”

What he said… the full chapter has in-depth information if you want to better understand the forces at work behind eggs, salt, and cooking, history, chemistry, etc. I will simply say I was glad I tested this myself and my understanding on the subject is significantly better. As for cooking eggs using salt, I might run a couple more tests when making scrambled eggs, but I would be inclined to add the salt earlier before cooking just based on this experience. I hope you enjoy and find this post useful! Until the next time! cheers!!!

related article: 1hr 63°C egg. The “perfect” soft “boiled” egg.