egg yolk sheets

Here is another example of a dish from the Cellar Masters wine dinner.  One of our first courses was to be a small strip of grilled maple-brushed pork belly served with an egg yolk sheet (bacon and eggs, get it?!?).  For the egg yolk sheet, we used a technique from ideas in food.  Naturally, to give full credit observe Alex and Aki's recipe for their egg yolk ribbons right here.  It's not an easy recipe to find because it is hidden in one of their comments.  Anyway, the process begins with eggs being cooked fully through at 63.8C.  After the eggs are cooled, crack them open and clean off the white and the yolk skin.  What you are left with will look like the yolks below.  The temperature coagulates the yolk into an interesting pliable ball.  You can actually mold it with your fingers and shape it, yet it retains the flavor of only very slightly cooked egg yolk... creamy, fatty, intense.

The next step is to lay the egg yolks down on a sheet of acetate.  You can see by the photo how well the yolks can be squeezed together into one mass.

Lay another sheet of acetate over the yolks and begin to spread it and smooth it out with a dowel or rolling pin.  I had quite a bit of yolk so I found it difficult to retain a perfect thickness level.  I am also wondering about purposefully rolling the yolks a bit thicker to give it more body for certain dishes... more of a flattened cube shape.

The compressed yolk sheet is then frozen.  Once it is completely frozen, remove it and cut it into whatever shape you desire.  Without an exacto knife, I opted for simple squares.  Also, this is much easier to achieve when the yolks are frozen.  They will thaw and become pliable fairly quickly so work fast.  Also, if they begin to thaw, freeze them again.  This can easily be done a day or two ahead and wrapped in the freezer.

This was the dish up for the pork belly.  Here I am applying just a drizzle of basil and chive oil to complete the presentation.  We added some fried potato nests for extra texture.  The yolk sheets were set on the plates ahead of time and allowed to thaw on the plate.

Here is a close-up of the finished dish.  Of course our minds are always moving in (sometimes goofy) different directions, so we could not help but notice how much the yolk resembles a slice of American cheese when cut into a small square.  This has us already itching to do an 'open-faced cheeseburger tartar' which would consist of a small round patty of steak tartar topped with a square of egg yolk sheet with the corners draping slightly over like melted American cheese.  We could then top it with complementary flavored micro greens to resemble lettuce and thinly sliced teardrop or cherry tomatoes.  We could even sit the tartar patty on a slightly toasted slice of brioche. 

You want fries with that?

Comments

[Aaron Janus]

Are the yolks plyable enough to roll around something, like a steak tartare roll( Steak and Eggs) Get it, ha ha
Would they beable to stick back together? What if you dehydrated the yolk sheets to make a crisp?
How long did you cook the eggs at 63.8C for?

[chadzilla]

The sheets could be rolled together. They seem to be fairly pliable and could be squeezed or crimped together or even cut into different shapes. Please take the time to view the applications used on the http://ideasinfood.typepad.com/ weblog as their photos and yolk sheets look a little cleaner than mine. I just took their idea and used it for my own applications.
The eggs cooked in a thermocirculator for about 90 minutes. In the introduction to the book "Sous-Vide," Herve This lists out the different temperatures that the various proteins in an egg begin to coagulate. By trying different temperatures, you can achieve a variety of textures with one egg. He states there that the time it takes an egg's outer temperature to reach the center is a little over an hour.
As far as the dehydration goes... we'll have to see.

[Martin Lersch]

Wow - the texture looks wonderful! Wish I had circulation bath. Do you have any idea on how sensitive the texture is to changes in temperature of let's say 0,1 or 0,3 degrees up or down?

[chadzilla]

I only have Herve This' section on eggs in the Introduction to Sous-Vide (by Joan Roca and Salvador Brugues) as a reference. He states the following specifics:
ovotransferrins- first to coagulate (61C/141.8F)
ovomucoids- second to coagulate (70C/158F)
lysozyme- third to coagulate (75C/167F)
ovalbumins (most abundant in the egg white)- fourth to coagulate (84C/183.2F)
These are all different proteins in the egg's albumen. He proposes that the science of egg cookery (or cooking in general) is more about temperature than time. It is a matter of setting an external temperature and the amount of time it takes the absolute center to reach the same temperature as the exterior. It is totally uniform in texture and flavor throughout. You can leave that egg in a set water bath for 4 or 5 hours and you will only coagulate the proteins that will do so at or below that temperature. It becomes possible to hold the egg almost indefinitely (as in the service time of a restaurant).
Anyway, I am out of my league here on the science side. I have only experienced the total deliciousness of eggs cooked this way as a chef. Long before I knew of sous-vide cooking, I was fascinated at how cooking scrambled eggs on the stove as slowly as possible (at least 30 minutes until done) made them taste much more creamy and pure. I mistakingly believed back then that fast cooking killed egg flavor, and time was more important than temperature. Now I know that it is more of a temperature factor and the time that it takes for that temperature to be consistent throughout a product. Of course, stirring eggs in a pan will allow for a constant temperature to be reached faster than a whole stationary egg sitting in a thermocirculator. If you have an induction burner, you can try this method with a good deal of accuracy.