Jan 21 2010

In Search of The Perfectly Cooked Egg – Sous Vide Style

January 21st, 2010 at 9:27 am (AST) by Jake Richter

As mentioned in my previous postings about sous vide cooking, my own adventures and exploration of sous vide started with the noble egg. Eggs are a wonderful natural food, and for those of you interested in the specifics of an egg’s composition, characteristics, and cooking, I again have to recommend Harold McGee’s “On Food and Cooking, 2nd Edition“, pages 68-117.

I still recall my first encounter with a sous vide cooked egged in a restaurant a couple of years ago, and after trying it I was in gastronomic heaven – the whites were like a soft, delicate custard, while the yolk was thick, rich, and gooey. I could not believe that I had simply settled for chewy, poorly textured, and mediocre eggs all my life. But if you don’t know about alternatives, you never know what you might be missing.

I personally am a huge fan of liquid yolks, and prefer my traditional eggs over easy or poached, and so my first sous vide cooking foray was to make the perfect soft-boiled egg.

McGee explains that egg whites and the yolk are composed of a variety of different proteins, all of which coagulate (solidify) at different temperatures, with the proteins in the egg whites thickening at higher temperatures than the egg yolks. He indicates that egg yolks tend to thicken at around 150°F / 65°C, and the various proteins in egg whites thicken at temperatures ranging from 145°F / 63°C to 180°F / 80°C.

Experiment #1 – Eggs au Naturel @ 64°C – Failed

My first attempt involved just putting the eggs in a water-bath at 64°C to get still runny but nearly solid yolks. Turns out it was a bad idea to put the eggs in the water directly, as they cracked slightly from both the temperature and from bouncing around as a result of the current caused by the immersion circulator, gumming the immersion circulator up with wisps of egg white as a result. I managed to get it clean, but it provided a great first lesson about cooking in a water bath – make sure that your ingredients are sealed away from the water to ensure the water remains clean and pure.

Experiment #2 – Eggs Sous Vide @ 64°C – Better

For the next experiment in cooking eggs sous vide, I actually used sous vide – I vacuum sealed the eggs to prevent them from cracking into the water bath and gumming up the works.

A Multivac vacuum sealer with a pouch with two raw chicken eggs

A Multivac vacuum sealer with a pouch with two raw chicken eggs

Here too I learned something. Normal sized eggs are less likely to crack when you vacuum seal them into a bag than bigger eggs. I assume that’s because big eggs are likelier to have thinner shells. I learned my lesson quickly, and only cracked one egg out of the dozen or so I used during my experiments.

Two vacuum sealed raw eggs in a Multivac vacuum sealer

Two vacuum sealed raw eggs in a Multivac vacuum sealer

One of the interesting things about cooking in a low-temperature water bath is that for most things, as long as your temperature is within a proper range for the thing you’re cooking and you have reached the point where the food has reached the target temperature throughout, you can cook the item for a wide range of time and still achieve the same result. Thus, the result of cooking an egg at 64°C for an hour is not hugely different from cooking it for three hours or five hours. The same applies to many meats in my experience.

Putting the vacuum sealed eggs in the water bath

Putting the vacuum sealed eggs in the water bath

With that in mind, I cooked my sous vide eggs at 64°C for around two hours. When I took them out of the bath and cracked them open, I found the yolks were unfortunately a bit more solid than I would like, but the whites had that wonderful light custard texture. The rest of the family agreed the yolk was too firm, and found the whites a bit runny.

A Sous Vide cooked egg at 64°C with a barely solid yolk and creamy whites

A Sous Vide cooked egg at 64°C with a barely solid yolk and creamy whites

Experiment #3 – Eggs Sous Vide @ 63°C – Perfect Yolks

Undeterred, I sealed up some more eggs and cooked them for a couple of hours at a slightly lower temperature – 63°C. The result was the whites were a wee bit runnier, but still like a delicate custard, and the egg yolks were perfectly cooked – gooey and rich but fully cooked. However, the rest of the family was still not wild about the consistency of the egg whites.

A Sous Vide cooked egg with a thick and gooey yolk and creamy whites - cooked at 63 degrees Celsius

A Sous Vide cooked egg with a thick and gooey yolk and creamy whites - cooked at 63 degrees Celsius

The yolk of the 63 degree Sous Vide cooked egg - rich and thick

The yolk of the 63 degree Sous Vide cooked egg - rich and thick

Experiment #4 – Long-cooked Eggs @ 70°C

As I was curious about the effect of long cooking of eggs to see whether time really doesn’t make a difference, I also cooked some eggs at 70°C for about 10 hours while I was experimenting with cooking pork ribs in the water bath at the same time.

The yolk was firm, but creamy, and the whites less runny but still delicate. This inspired the next and final (for now) experiment.

Experiment #5 – Separately cooking the whites and yolks

For the final egg sous vide experiment, I took eight eggs and separated the whites and yolks into two cooking-safe bowls. While I am certainly capable of separating whites and yolks using just the egg shell itself, I find I am more productive with a dedicated separating device as pictured below. Plus, it’s cute. Trick to using it properly is to slide the egg innards into the device instead of dropping the egg insides onto the device, as the drop creates enough force that the egg yolk membrane might burst.

Jake's way to separate egg yolks and whites

Jake's way to separate egg yolks and whites

Eight eggs - separated into whites and yolks

Eight eggs - separated into whites and yolks

Once I was done with separating the eggs, I vacuum sealed each bowl. Another two lessons learned here: First, use bowls or jars that leave about one-third of the top empty – do not fill them to the rim; and second, don’t seal to maximum vacuum – 85-90% vacuum (or 150-100 millibar or so) should be sufficient. Not having known these things, I found my whites and yolks sucked a bit out of the containers during the vacuum sealing process, which in turn burst a couple of the yolks. Fortunately burst yolks still taste good.

The whites and yolks after being vacuum sealed - note that a couple of yolks burst

The whites and yolks after being vacuum sealed - note that a couple of yolks burst

Both were cooked for about an hour at 63°C (to cook the yolks just right). The yolks were then removed along with enough water to keep them warm while the whites got cooked for another hour at 70°C.

Starting the eggs in a water bath - both at 63C, and then the whites for a while longer at 70C

Starting the eggs in a water bath - both at 63C, and then the whites for a while longer at 70C

Result? The yolks were great, of course, and the whites far less runny – just like when I long-cooked the whole eggs, but still custard-like, and most importantly, more to my family’s liking.

Meanwhile, the eggs have been unbagged - creamy rich yolks, and custardy whites

Meanwhile, the eggs have been unbagged - creamy rich yolks, and custardy whites

However, when we are next up for another egg sous vide experiment, we may try the whites at somewhat higher temperatures to see if that makes a difference, since coagulation of some of the egg white proteins is not complete until around 80°C.

Jan 19 2010

The Making of Low Carb Chili Rellenos

January 19th, 2010 at 10:09 pm (AST) by Krystyana Richter

After a year of making chili rellenos with jalapeño peppers instead of the poblanos required in the original recipe, we finally found poblano peppers here on Bonaire! Even making the recipe for the last year, it is far from perfected, but we have discovered ways to make it easier on my mom and myself.

Krystyana and Linda's low carb Chili Relleno

Krystyana and Linda's low carb Chili Relleno

What makes our recipe low carb is that regular chili rellenos recipes require a corn flour batter to coat the peppers with. Flour is obviously not low carb. So we use beaten eggs instead.

The first thing to do when looking for the perfect pepper for this recipe is an unblemished jalapeño or preferably poblano pepper.

– 6 poblanos (or 10 jalapeños)
– 3 x 8 oz. packs of full fat cream cheese
– 1 x 8 oz. Four Cheese Mexican blend pack
– 4 eggs
– 3 paper bags

First of all, set your oven to 350 degrees Fahrenheit. Then wash the poblanos and dry them off well. On a gas stovetop, lay a flat grill rack on the burner area. You need an open flame for roasting the peppers. Strategically place the peppers so that they are directly over the flame. Turn the pepper when the side facing the flame is entirely black with bubbling skin. When the pepper is black on all sides, stuff the pepper into a paper bag and roll up the opening to keep the steam in. After about 5 minutes, the peppers should be cool enough to pick up.

At this point, and when using jalapeños, I would search for gloves or a victim. The burn in a jalapeños can vary but I would not ever take a chance with getting a hot one while barehanded. This is due to a previous accident when making chili rellenos with jalapeños. After gutting about 10 of them, my fingers started hurting like crazy. My mom and I tried everything to make it stop, from sour cream to aloe. It did not work…. And that is why I suggest gloves.

Take a pepper out and start peeling off the skin while attempting not to break apart the flesh of the pepper. My mom used a small knife for this, but finger nails are almost as successful. We peeled the skin into the sink because this is long process.

Take a knife and slit one side of the pepper, from the stem to the very tip of the pepper. The seeds will be just as hard to take out of the pepper as the skin was to remove and just as sticky. The likelihood of making a gaping hole in the opposite side of your slit is high, so be wary of pulling on strings of the flesh. And wear gloves if it’s a jalapeño.

Mix the cream cheese and the four cheese Mexican blend in a bowl until thoroughly mixed.

Take out a large casserole dish and spray with Pam or grease it with butter. Lay the peppers on the bottom of the casserole dish and start stuffing the peppers with the cheese mixture. Don’t overstuff them. The rest of the cheese can rolled up into little balls and placed around peppers. They melt really well and are yummy to eat separate from the peppers as well.

Beat the eggs in a bowl and brush it over the peppers and dump the rest into the dish. Put the peppers into the oven for 30 minutes, or until the egg is cooked.

Bon appetite!

Jan 7 2010

Cooking Sous Vide

January 7th, 2010 at 12:30 pm (AST) by Jake Richter

I spent a couple of weeks last month performing experiments in my kitchen using a cooking technique known as “sous vide” (means “under vacuum” in French).

In sous vide cooking you generally vacuum seal (or use inert gases to supplant oxygen) foods and then cook them for a long time at low and consistent temperatures (typically in the range of 50-72 degrees Celsius / 122-158 degrees Fahrenheit).

Sous vide cooking is quite equipment intensive, as it requires, at a minimum, a decent vacuum sealing device, and a way to cook at specific temperatures with a high degree of accuracy (.1 degrees Celsius accuracy is desirable). While there probably are some passable low-priced solutions, if you’re serious about doing a wide range of sous vide cooking at home, I would strongly suggest budgeting about $5,000 for the two key components you will need – the vacuum sealer being one, and the other discussed below.

The Techne TE-10D Immersion Circulator

The Techne TE-10D Immersion Circulator

The common way to achieve the accurate temperature needed is via a device known as an thermal immersion circulator, placed in a water bath. The immersion circulator sucks in water, and then jets it out, heating the water in the process. A highly accurate thermometer built into the immersion circulator is used by the device to ensure the water is not over-heated, but instead kept at the exact temperature programmed into the device. Thermal immersion circulators originated as a piece of laboratory equipment for chemical and biological work, and the original idea to use such a device stems from the “bain marie“.

A Multivac vacuum sealer with a pouch with two raw chicken eggs

Our Multivac C-100 table top vacuum sealer

For my kitchen, I had invested in a C-100 vacuum sealer from Multivac, based on a recommendation and contact information provided by Wiley Dufresne, chef at wd-50, New York’s landmark molecular gastronomy restaurant (although they call it “New American” cuisine on the web site).

Interesting side note: Unbeknownst to us, Wiley sat behind us at a presentation on cooking with liquid nitrogen in New York City about 16 months ago, and by coincidence recognized us from that class when we dined at his restaurant the following night. Wiley invited us into the kitchen for a tour after dinner to show us his modern kitchen and equipment, including containers with all of his “ingredients”, and described some of the cooking techniques he uses. All I can say, other than “Thank you Wiley!”, is that you should not miss an opportunity to try wd-50 the next time you’re in New York City!

A web site on sous vide pointed us to some sources for immersion circulators. We ended up going to the Cole-Parmer web site, which offered a number of options for immersion circulators. I opted for the Techne TE-10D (pictured further above), which features a digital display (and settings), and also a screw clamp which can be used to mount the immersion circulator onto a large pot which holds your cooking medium (water), and which is turn is used to cook your vacuum sealed bags of edible goodness.

Sous vide, as a form of culinary artistry, is still evolving. Its origin in food preparation came from a desire to seal food away from the things that cause it to go bad, such as oxygen and the bacteria that need oxygen to multiply (although there are anaerobic bacteria that could cause problems). At some point someone tried cooking vacuum sealed food while still in the plastic bag and found it could make a dramatic improvement in juiciness, as well as retention of flavor and nutrients. Part of that is because the food is not exposed to air while it cooks. Air will oxidize meats and change their color (brown, typically) and flavor, and similarly, vegetables will lose flavor when cooked in water, steam, or in a pan with fats of any sort.

However, in a vacuum, that’s not an issue – the meat cooks in whatever marinade you have it stored in, as well as its own juices, which would otherwise evaporate. Further, by being able to cook meat and other foods at exact temperatures, you can select the proper level of done-ness throughout instead of the temperature variations that oven-based cooking produces – namely higher heat and thus dryness on the outside going into the meat, and cooler temperatures and less done-ness inside at the center.

What I find fascinating about this process is that it combines science with food, as you need to learn and know at what temperature various foods change states. For example, the proteins in egg yolks firm up at just around 65 degrees Celsius (149 degrees Fahrenheit), but the several different parts of egg whites coagulate at different temperatures, both higher and lower than the egg yolk. And beef is a perfect medium rare (as far as I’m concerned anyhow) at 54.5 degrees Celsius (130.1 degrees Fahrenheit).

One of the cautions with sous vide cooking is that the same low temperatures at which you cook meats are the same temperatures at which bacteria thrive, so if your food source or preparation are not properly hygienic, you could be breeding organisms which lead to food poisoning. There are a number of ways to minimize or remove the risk, including thoroughly cleaning and washing foods before sealing them, searing the outside of meats at high heat in a broiler or pan to quickly kill off any unwanted guests, or using alcohol in your sauces or marinades. More details on this subject can be found here.

A book I am reading about Sous Vide right now which promises to be excellent (and some say it’s the “Bible of Sous Vide”) is the difficult to obtain and unfortunately expensive ($160 and up) “Sous-Vide Cuisine” by Joan Roca and Salvador Brugués. I bought mine here. Thomas Keller of French Laundry and Per Se fame also has a book out on sous vide cooking, “Under Pressure: Cooking Sous Vide” which has some fascinating recipes but does not really address basic sous vide experimentation. And finally, no discussion of food science would be complete without a recommendation of Harold McGee’s most excellent “On Food and Cooking, 2nd Edition“.

In order to not make my posts novella-length, I’ll address actual sous vide cooking experiences in another entry to be posted early next week. For now, let me leave you with a photo of a sous vide cooked egg – creamy, custardy whites with a thick gooey full-flavored yolk. Trust me. It was delicious.

The yolk of the 63 degree Sous Vide cooked egg - rich and thick

The yolk of a 63 degree Sous Vide cooked egg - rich and thick

Nov 4 2009

Fluffy Scrambled Eggs

November 4th, 2009 at 6:23 pm (AST) by Jake Richter

Even foods we consider ordinary can surprise when they are prepared differently. Surprisingly, the preparation doesn’t need to be very different to make a difference.

A perfect example is scrambled eggs. In the past, my favorite way of making scrambled eggs was simply to crack the eggs over a pan and scramble them as they cooked. The result looks colorful, and the texture varied based on the combination of yolk and albumin (the clearer part of the egg).

Linda, my wife, would scramble them in a bowl before cooking them. Some folks may add a bit of milk as well, and over at IHOP, they add a bit of pancake batter (at least that’s what the menu suggested the last time I ate at an IHOP).

But a book I have been reading on and off – Harold McGee’s most excellent “On Food and Cooking – The Science and Lore of the Kitchen” (2nd edition) – suggests that chefs have known for centuries that adding a bit of acid to scrambled eggs makes them extraordinarily fluffy when cooked. In the voluminous chapter on all things “egg” in his book, McGee explains in depth the structure of proteins in egg yolks and albumin, as well as the impact that acid has on those proteins.

Even if you don’t care about the science involved, you can still benefit from McGee’s analysis. The next time you scramble up some eggs before cooking them, add a small squeeze of lemon juice or a bit of fruit juice or even vinegar – a quarter or half teaspoon will do. The amount of lemon juice or other liquid you add is so miniscule you cannot taste it, but the result will astound you – you will likely never have had eggs so fluffy.

And you will likely never go back to chewy or rubbery scrambled eggs again.