Sous vide is the four-star chef's secret to perfectly cooking almost anything. That kind of precision requires expensive gear—unless you build it yourself. Cooking for Geeks shows us how to engineer this miracle cooking technology ourselves.
There's never been a better time to be in the kitchen as a hacker. In the past few years, the swinging doors leading into the kitchens of high-end restaurants such as wd~50, minibar, and el Bulli have been opened up, revealing kitchens that would be more familiar to Charlie and the Chocolate Factory's Willy Wonka than the esteemed French Chef Auguste Escoffier. Vacuum chambers. Centrifuges. Cold plates. Water baths. To an outsider, the hardware in modernist cuisine must seem maddeningly insane. With a little explanation—and some tinkering—not only can you understand these tools, you can make your own versions. Here's how.
Water baths Called sous vide in the culinary world, you can think about this cooking technique as a high-tech merger of boil-in-bag and slow-cooking. At its simplest, sous vide cooking is about immersing a food item into a precisely temperature-controlled water bath where the temperature is the same as the target temperature of the food to be cooked. If you like your steak cooked medium-rare (145°F / 62.8°C), sticking it in a water bath set to that temperature means it can't overcook. Think of it like ultra-low-temperature poaching that cooks things perfectly each and every time. No more burning the dinner!
The pros use a device called an thermal immersion circulator—essentially, a water heater with a propeller to agitate the water, along with an agitating price tag: $US1000. For chem labs, the precision is worth the cost, but you don't need that level of accuracy to get great results in your kitchen. Snag a slow cooker, thermocouple, and a thermostat controller, and you're ready to make your own sous vide rig.
First, the slow cooker. The slow cooker will serve as the brawn, holding the water and providing the heat source. Find a cheap slow cooker—you need one that will turn back on after losing power-and look for one that has a physical knob; digital models reset and stay off after power has been cycled.
Next, the thermocouple. You'll need a type J thermocouple, which is made of materials that give it good sensitivity in the temperature ranges of sous vide cooking. This should cost around $US15 to $US20; search online for "type J probe" or search for part 3AEZ9 at Grainger.
Finally, the temperature controller. Just about any thermocouple-based temperature switch will work; look for one that runs off 12 volts DC, such as Love Industries' TCS-4030, which runs about $US75. Snag a 12-volt wall wart (AC/DC power adaptor) while you're at it.
Once you have all the parts on hand, it's a relatively straightforward procedure to perform the lobotomy on the slow cooker: hook the thermocouple up to the probe inputs on the switch and connect the 12-volt power supply to the switch, then snip the slow cooker's electrical cord and run one side of it through the switch. Create a small hole in the lid of the slow cooker and poke the thermocouple through. Make sure you use enough water in the slow cooker that the thermocouple makes contact with the water when the lid is on!
Once your rig is ready to go, set the temperature to your desired target temperature, drop your fish or meat in, and set a timer. Ahh, there's the catch. What temperature should you dial in? And how long to set the timer? Is it even safe? Knowing what temperatures to use and how long to hold the food at that temperature to properly pasteurise it requires knowing some food science. Douglas Baldwin maintains a great guide to sous vide cooking available for free online at http://www.douglasbaldwin.com/; I also address these questions in Cooking for Geeks. Here's one recipe to get you started.
Beef Steak Tips
With sous vide cooking, food is typically placed in a bag and vacuum-sealed to remove any air. The bag prevents the water from interacting with the food; the vacuum-sealing removes any air so that the bag doesn't float. (You can still add marinades to the bag.) If you don't have a vacuum sealer, you can use a resealable plastic bag: submerge most of the bag, leaving just the sealing strip at the top above water, and then seal it.
Prepare the beef steak tips for cooking by placing in a vacuum or resealable bag:
• 1–2 pounds (~1 kg) steak tips, cut into individual serving sizes (7 oz / 200g)
• 1–2 tablespoons (15–25g) olive oil
• Salt and pepper, to taste
Shake to coat all sides of the meat with the olive oil, salt, and pepper. Seal the bag, leaving space between each piece of meat so that the water bath will make contact on all sides.
Cook in a water bath set to 145°F / 62.8°C for 45 minutes. Remove bag from water bath, snip open the top, and transfer the steak tips to a preheated hot pan, ideally cast iron. (Sous vide cooking doesn't get hot enough to create that rich, browned outside from the Maillard reaction, so a quick sear adds that.) Sear each side of the meat for 10 to 15 seconds. For a better sear, don't move the meat while cooking each side; instead, drop it on the pan and let it sit while searing. Allow to rest for a few minutes, and then slice and serve as desired.
Cold plates If you're anything like me—or Charlie on his tour of The Chocolate Factory—you'd probably make a beeline for the sweeter side of the menu. And I don't blame you: our brains are wired to crave sugary, sweet, and salty things; probably because those things are all relatively rare in the jungles and grassy plains that we evolved out from.
Coming up with something new for those with a sweet tooth continues to be a challenge for even the Willy Wonkas of the culinary world. After all, figuring out how to make a meal taste great while also challenging our senses is a tricky proposition and requires an audience open to experimentation.
One such experiment that's still playing out is that of a cold plate, nicknamed "the anti-griddle" by the inventors at the restaurant Alinea and scientific equipment manufacturer PoliScience. As the name suggests, instead of acting like a griddle that adds heat to whatever you drop on its surface (Mmm Philly cheese steak), and anti-griddle pulls out heat from whatever hits its top. Drop a dollop of, say, whipped cream on it, and the side that hits the griddle freezes up. Flip it over like a pancake, set the other side, and it's a frozen lollipop with the middle still runny. By itself it's nothing special, but combined with other components on a dessert plate, it can bring an element of surprise and convey flavours and textures in new ways.
If you don't want to spring for a commercial unit, you can make a do-it-yourself version by using dry ice (ice cubes aren't cold enough), ethanol, and a sheet of stainless steel (you can order a piece from a distributor such as McMaster-Carr if you don't happen to have one lying around).
1. Rig up a bed of crushed dry ice. Try using a cookie sheet placed on top of a wooden cutting board. The cookie sheet will hold a dry ice/ethanol slurry, and the cutting board will provide insulation between the extremely cold cookie sheet and your countertop. Alternatively, if you have the lid to a Styrofoam container, using the inside, indented part can serve both purposes.
2. Pour a small amount of ethanol onto the bed of crushed dry ice—enough to create a level top. (You can use rubbing alcohol or cheap vodka.) The ethanol will remove any air gap between the pieces of dry ice and the stainless steel griddle, and it won't cause the dry ice to froth in billowy clouds like water would. Think of the ethanol as being like thermal paste on top of a CPU.
3. Plop the square of stainless steel on top of the ethanol-topped dry ice. It should be a complete contact fit, just like a heat sink on top of a CPU.
4. Spray or coat the top surface of the stainless steel with a nonstick cooking spray, butter, or oil.
5. Drop your food to "cook" on the surface, smoothing it out into a pancake shape if desired. After 10 seconds or so, use a spatula to flip it and set the other side. As a starter, try whipping some cream up in a bowl with a bit of sugar and chocolate syrup.
An anti-griddle isn't going to win you any culinary awards by itself. Still, it's fun to see how things work, and while you might not be able to produce something like the delights emerging from either Willy Wonka's Chocolate Factory or the swinging doors of a luxury restaurant, bringing that playful attitude and inner curiosity about how things work into the kitchen will make you a better cook. And besides, it's fun!
Cooking For Geeks just might get every geek you know excited about cooking. Written by Jeff Potter, a software engineer turned food writer, this cookbook is for anyone who likes to understand how things work. The best-selling book comes packed with outstanding, well-thought out recipes recipes—and give readers enough information to enable them to go off-recipe. Indeed, when you think about it, recipes are nothing but code.
Jeff Potter has done the cubicle thing, the startup thing, and the entrepreneur thing, and through it all maintained his sanity by cooking for friends. He studied Computer Science and Visual Art at Brown University.
Cooking for Geeks
By Jeff Potter
Copyright 2010 Atof Inc. All rights reserved.
Published by O'Reilly Media, Inc.
Cooking for Geeks is available for purchase at Amazon.