I think it is a sad reflection on our civilization that while we can and do measure the temperature in the atmosphere of Venus we do not know what goes on inside our soufflés.
Howdy, neighbors! This is the first of a short series of posts on molecular gastronomy. If you've never heard of this before, plant yourself in front of the Food Network for a couple of hours and you're bound to see it in some form. You can also watch Marcel's Quantum Kitchen on Syfy, but to be honest there's more drama and less cooking done on that show.
For a history of molecular gastronomy, read through the Wikipedia article. It has its roots in some hardcore science and, as a lover of both science and food, I couldn't pass up an opportunity to learn something about this form of cooking. I stumbled upon a great site, Molecular Recipes, that had a load of information and recipes to explain a lot of the processes.
Today we're going to use the ingredient agar-agar. This is made from sea algae and is typically used as a vegetarian substitute to gelatin. Its use is very similar to gelatin: add to liquid, boil, allow to cool. It is considered a hydrocolloid, meaning that the colloidal properties (that cause the creation of the gel, in this case) are dispersed in water. Maintained at a certain temperature it has the appearance of a solid. Heated, it can return to liquid state. (Ever notice Jell-O melts in warm temperatures?)
Agar-agar is used in a couple of different ways in molecular gastronomy. One of the more common uses is to create a "noodle", such as tomato agar spaghetti. To do this, the agar-agar is combined with a hot liquid, then injected into tubing and immediately cooled in an ice bath, then forced out of the tubing. You can read more on that process at Molecular Recipes. Agar-agar powder is easier to dilute in water than the flakes, but if you have flakes you can grind them in a coffee grinder or spice grinder.
Spherification is another technique used in molecular gastronomy. A common example of spherification would be when a liquid is combined with sodium alginate, then dropped into a calcium chloride bath. When the liquid and sodium alginate contact the calcium chloride solidification occurs, creating a jelly-like coating around the liquid. Left too long, the entire sphere will turn into jelly, but if served immediately the effect is described as something similar to a Fruit Gusher, or if made small like caviar or roe.
There it was: Immediately I thought of turning an egg into caviar. Then I immediately thought of how gross it would be to have liquid egg burst into your mouth upon breaking the membrane. I thought to combine the two ideas: using a hydrocolloid to solidify a liquid and shaping this into spheres.
Note: For this recipe I used 1.6% agar-agar of the total liquid. I've read that some have had better luck with 2.5%. If you use 2.5%, the amounts needed for the whites and yolks would be 6.25g and 3.125g, respectively.
You can obtain a PDF of this recipe by clicking here.
- 1 egg white
- 250g (less weight of egg white) stock
- 4g agar-agar powder
- 1-2 cups canola oil, kept in freezer
- ice and ice cream salt (optional)
First, separate the egg yolk from the white and measure both. Subtract this amount from 250. You want the total of egg white and stock to equal 250 grams.
Weigh out the stock. Remember, 250 grams minus the weight of the egg. (I was 1 gram off.)
Next, bring the stock to a boil. Add the agar-agar and whisk vigorously to combine.
Now, work quickly. Using a small ladle, spoon in a small amount of the hot liquid to the egg white and whisk. We are tempering the eggs here so that they don't immediately cook as soon as they hit the hot liquid. Add small amounts at a time until about half of the hot liquid has been incorporated into the egg whites.
Slowly pour the tempered egg whites back into the rest of the stock. Bring to a quick boil, then remove from heat. Give another whisk.
NOTE: As you drop the hot liquid into the cold oil, the temperature of the oil will rise as it attempts to reach an equilibrium. To combat this, I put ice, ice cream salt, and some water in a bowl and put the container of oil in this. The ice cream salt causes the ice to melt faster, dropping the temperature and keeping it lower than just ice and water would.
Take the canola oil from the freezer (and nestle it in the ice, ice cream salt, and water bath if you wish) and very quickly start adding in the egg white liquid, one drop at a time. I used a syringe and moved more quickly than I should have, but you can use whatever method works for you.
As soon as it hits the cold canola oil it will solidify. Try and keep the individual drops a uniform size.
Pour the oil through a fine sieve and run the egg spheres under cold water to wash off excess oil. Note that not all of them are perfectly shaped. If the solidification does not occur immediately, and two droplets touch in the oil they will combine and form an oddly shaped lump. I liked the variety, but you could probably use a spoon or colander with equal sized holes to "sort" the spheres, if you wish. These can now be set aside while the yolks are handled.
- 1 egg yolk
- 125g (less weight of the yolk) stock
- 2g agar-agar powder
- 1-2 cup canola oil, kept in freezer
- ice and ice cream salt (optional)
The same process will be done with the yolks, just using half of the stock and half of the agar-agar.
Since these reminded me of roe so much, I thought it would be best to present them in a familiar way. Ikura sushi is usually presented as a small cup made out of nori (seaweed sheets) with a rice base and filled with salmon roe. Egg on its own is always a breakfast food to me, so I thought replacing the rice base with a quick potato and pancetta hash and the nori with a dehydrated ketchup sheet would be an interesting take on it.
I made the ketchup from scratch using the Sauced recipe from Serious Eats. I'm not a big fan of ketchup since it usually overpowers the flavor of any dish, but this ended up being a very flavorful and spiced ketchup. Dehydrating is another commonly used molecular gastronomy technique. I've made jerky and dried fruits before, as well as some fruit leather, so I thought this could work the same way. Using my dehydrator, I followed the instructions for making fruit leather: essentially spread it out on the liquid tray and set the temperature to 135 degrees. After about 5 or 6 hours, I was able peel the sheet from the tray.
Unfortunately, the camera decided not to save the photos of the strips being cut or the egg ikura being assembled and I didn't have enough of the dehydrated ketchup to redo this step.
For the base, I took half of a small potato (K was making a slow cooker chicken with potatoes, but boiled would work fine) and mashed it with a fork. In a small saucepan I cooked some diced pancetta, then mixed it with the pancetta and formed two small patties and fried them in some of the leftover canola oil. (Alternatively, you can make a more complex hash with some very finely diced onions and peppers.) I measured the strip of dehydrated ketchup, about an inch high and six inches long, and wrapped it around the small patty of fried potato. Then I spooned in egg white spheres until it was just about full, and topped it with a smaller spoonful of egg yolk spheres.
The taste was kind of surprising! I thought the ketchup strips would be too tough but with the heat from the potato they were softened and easily melted in my mouth. The egg spheres gave the impression of "popping" but were solid all the way through. They didn't add much to the flavor, but I felt the texture was more important than anything. The potato helped add substance and more flavor (especially with the pancetta) to the whole thing.
Obviously this is very time consuming. As you can see, creating uniform spheres using this method is pretty difficult and the payoff is pretty minimal. I liked experimenting with the agar-agar and certainly plan on using it again in the future. Something I love about this whole style of cooking is the ability to change the way a food is presented. The quote in the beginning of this post stayed with me throughout this process: We understand so much about the world and the universe, but so little about the processes involved in cooking.
We should never stop asking why and never stop trying something new with the answers we're given. Until next time, neighbors.