Jan 24 2010

Sous Vide Duck

January 24th, 2010 at 8:13 am (AST) by Jake Richter

While I love chicken, I absolutely adore duck in all its many forms, from duck confit and Peking duck to duck liver and duck a l’orange, and everything in between. Unlike a chicken, which at best struts about and thus only has dark meat around its legs and thighs, a duck is designed to walk and fly, thus using all of its muscles. That means that all of a duck’s meat is rich, dark meat, laden with delicious bits of fat.

My goal, therefore, was to cook a duck, sous vide style. I searched around for ideas on how to best prepare sous vide duck and found components in various places, including the Foodie at Fifteen (now 17) Blog, Thomas Keller’s “Under Pressure: Cooking Sous Vide”, and my own father’s recipe for slow-roasted duck.

For our sous vide duck we started with a thawed frozen duck

For our sous vide duck we started with a thawed frozen duck

First step was procuring a duck. Being that other than goat and occasionally chicken, we have no access to fresh meat on Bonaire, I managed to procure a frozen whole duck from the aptly named “The Island Supplier”. After thawing it out over a couple of days in the refrigerator, I split the duck up into six parts (thanks to the directions of Nick of the Foodie at Fifteen blog) for easier cooking in my water bath later on.

The duck is sectioned to make it easier to cook in the water bath

The duck is sectioned to make it easier to cook in the water bath

Adapting part of a duck confit recipe from Thomas Keller’s book, I made a salt rub mixture containing garlic, thyme, salt, pepper corns, and bay leaves which I then applied to all of the pieces of duck liberally and then leaving in a refrigerator for several hours. The salt rub both draws out moisture from the duck while also seasoning it at the same time.

Our salt rub mixture - salt, peppercorn, garlic, bay leaf, and thyme

Our salt rub mixture - salt, peppercorn, garlic, bay leaf, and thyme

The duck after being thoroughly rubbed with the seasoned salt rub

The duck after being thoroughly rubbed with the seasoned salt rub

Next step was to rinse off all the salt from the meat. This went pretty well except for the wings, where I later discovered I had not rinsed quite as rigorously as I perhaps should have. I then vacuum sealed the duck parts, and set them to cooking in a water bath at 83°C for over five hours. Because duck is such a fatty meat, this resulted in rendering the fat to liquid form and then self-basting the duck in the meat juices and rendered duck fat, much like how one would prepare a confit.

After rinsing the salt rub off with water, we vacuum seal the duck parts

After rinsing the salt rub off with water, we vacuum seal the duck parts

We start the duck in the water bath

We start the duck in the water bath

Because of the high temperature of the water bath, we were generating a lot of steam, which was causing both water loss and forcing the immersion circulator to work a lot harder to keep the bath at the right temperature. We solve both problems by insulating the water bath with aluminum foil.

To avoid excess heat and water loss from steam we cover our water bath with aluminum foil while cooking the duck

To avoid excess heat and water loss from steam we cover our water bath with aluminum foil while cooking the duck

The final step was to crisp up the skin of the duck, as there’s nothing quite like crispy duck skin to make a meal of duck complete. But this is where we ran into some problems.

After over five hours at 83C, the duck is now perfectly cooked, with much of the fat rendered to liquid

After over five hours at 83C, the duck is now perfectly cooked, with much of the fat rendered to liquid

The first attempt at crisping the duck was to simply take all the rendered duck fat and juices and try to fry one of the pieces of duck in it. However we could simply not get this to brown the skin. We figure that’s because there was too much fat to get it up to the temperature we needed.

We tried using the duck juices and fat to fry the duck parts to crisp them, but that failed - too much liquid

We tried using the duck juices and fat to fry the duck parts to crisp them, but that failed - too much liquid

We solved our browning/crisping problem in two different ways. One was using a small broiler. This, by far, did the best job of giving us the uniform brown, crisp exterior we were looking for. The other was to use only a little bit of duck fat in a hot pan and sear the outside of the duck. This worked, but not as well, because duck is, well, lumpy, and we could not evenly heat all of the exterior of the pieces of duck we tried to finish off this way.

A sous vide duck leg section, fresh from being crisped in the broiler

A sous vide duck leg section, fresh from being crisped in the broiler

A sous vide duck breast part after being crisped in a pan with a very little bit of duck fat

A sous vide duck breast part after being crisped in a pan with a very little bit of duck fat

However the duck was browned, it turned out excellent. The meat was moist, tender, and flavorful, and the crispy skin was mouthwateringly delicious. Definitely a meal to repeat (with the caveats listed above).


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