Introduction: Sous Vide Cooker for Less Than $40

sous vide
[soo VEED]
French for "under vacuum," sous vide is a cooking process in which food is encased in an airtight plastic pouch (typically vacuum sealed) and cooked for a long period of time at a (precise) low temperature.  

Using traditional methods of cooking, you might put a steak on a 750 degree grill, attempting to get the center of the steak to a perfect medium-rare temperature of 130 degrees, without cooking the outside of the steak until it's gray and lifeless.  To make it even more difficult, even when you take the steak off the grill, the temperature of the center continues to increase due to the heat of the meat surrounding it.

The magic of sous vide is that you cook the entire piece of meat at the precise temperature you like.  To cook a steak to the perfect medium-rare temperature of 130 degrees, you cook the steak in 130 degree water.  It takes a lot longer to get a steak to 130 degrees by cooking at 130 degrees, but the benefits are worth it.

1) It's impossible to over-cook.  No part of the steak can get over cooked.
2) The entire steak, from "coast to coast" is exactly how you like it.
3) Timing is easy.  I usually cook my steaks for somewhere around six hours.  If your guests are late, an extra hour (or three) doesn't make any difference.
4) The fat in the steak is always perfectly rendered.  It's absolutely amazing how great inexpensive cuts of meat turn out when cooked sous vide for six hours.  

There are many sous vide cookers out there.  I'm more of a do-it-yourself (cheap) kind of guy, so I built my own sous vide cooker for less than $40.  The fancy, $500 cookers have water circulators and tenth-of-a-degree precision, but from my experience, that isn't necessary.  For $40, you can make absolutely incredible steak!

Step 1: Parts

The heart of the sous vide cooker is a digital temperature controller.  You can easily find them on eBay for less than $25, including shipping.  Just be sure the controller you buy operates at 110V, and can display temperature in degrees Fahrenheit (if that's what you want).

Notice how the controller has 8 screw terminals (second picture).
3 & 4 - These terminals give the device power to operate.
7 & 8 - The temperature sensor connects to these terminals.
1 & 2 - When the controller senses that the temperature is below the set temperature, it closes this relay.  When it's at (or above) temperature, is opens this relay.  We'll use these two terminals to route power to an outlet.

Other parts
Box - We'll also need an enclosure to put everything into.  I used a 4x4x4 electrical box I purchased at Lowes for $9.
Outlet - I like a single outlet.  I got this one from Home Depot for $3.  I had to cut the tabs a little to make it fit in the box.
C14 receptacle - This is a plug like you find on computers.  Get these from eBay, too.  They should be less than $1 each.
C13 power cord - If you don't have one around, you should be able to pick one up for a couple of bucks.  Check eBay or
#4-40 x 3/8" screws - You'll need a couple of screws to connect the C14 receptacle to the box.
14 AWG wire
Wire nut
3 female disconnects
- Optional, but very helpful

Step 2: Installing the C14 Receptacle

Create a template - It's pretty difficult to measure and draw on the plastic box, so I like to make a paper template and tape it to the side of the plastic box.  I use Google SketchUp because it's free, easy to create templates, and print them exact size.
Drill holes in corners - Use a small drill bit (e.g. 1/8") to drill holes at the corners of the template.
Dremel - Use a Dremel (or similar) tool to cut the straight lines.  Keep adjusting the hole until the C14 receptacle fits. 
Mark screw holes - Insert the receptacle and mark the screw holes.  Drill appropriately sized holes for the screws you're using.
Install - Install the receptacle using short (e.g. 3/8") screws and nuts.

Step 3: Cut Holes in the Top of the Box

The top is done the same way the receptacle was installed in the side of the box.

Template - Tape the template to the top of the plastic box.
Drill holes in corners - Use a small drill bit (e.g. 1/8") to make the corners of the hole.
Dremel - Use a Dremel (or similar) tool to cut the straight lines.  Keep adjusting the hole until the controller fits.

The circular hole for the outlet is a little different.  

Drill the circular hole - My outlet was a slightly less than 1 3/8" in diameter.  I used a 1 3/8" drill bit to make the circular hole.  Be sure to clamp the box top to the drill press before making this hole.
Mark screw holes - Insert the single outlet and mark the screw holes.  Drill appropriately sized holes.
Install - Install the outlet with the screws that came with it.

My box had "feet" on it.  For a more finished look, I used the Dremel to remove the feet.

Step 4: Install the Temperature Controller

The temperature controller should fit snugly in the rectangular hole you made in the box top.  The face of the controller is slightly larger than the body, so any imperfections in the rectangular hole are hidden.

The controller is held in place with the orange clips.  The clips slide in grooves in the controller.  Snug them up tight against the top so the controller is secure.

Step 5: Wiring

Ground - The ground wire on the C14 receptacle connects directly to the ground on the outlet.
Load - The load from the C14 needs to be split and connected to the relay pin (1) on the controller and to the power pin (3) on the controller.  The second relay pin (2) connects to the load of the outlet.
Neutral - Connect the neutral wire on the C14 receptacle to the neutral screw on the outlet.  Using the second neutral screw on the outlet, connect to the neutral pin (4) on the controller.

Note:  The female disconnects make it much easier to connect the load, neutral, and ground to the C14 receptacle.  Without them, you will probably need to remove the C14 to make the connections.

Temperature probe - Drill a small hole in the side of the box.  Pass the wires of the temperature probe through the hole, and connect to pins 7 and 8 of the controller.

Carefully tuck all the wires into the box.

Step 6: Testing

Testing is fairly easy.

1) Plug in your controller and you should see something on the display.
2) Plug a lamp into the outlet on top.
3) Press the "Set" button and release.
4) Press the up or down arrow to set the "cooking temperature."  For testing purposes, set it to 70 degrees.
5) Don't touch the temperature probe.  The controller should display the current temperature.  The "Work" LED will illuminate and the lamp will turn on.
6) Pinch the temperature probe between your fingers.  You'll see the temperature rise.  When it reaches 70 degrees, the "Work" LED and the lamp will turn off.

If something doesn't work, check your connections.  Something probably came loose while you were tucking wires into the box.

Step 7: Cooking Sous Vide

Prep the crock pot
1) Fill you crock pot with water.
2) Plug it into your sous vide controller.
3) Plug the sous vide controller into the wall.
4) Press the "Set" button and adjust the temperature.  My family likes our steak at 137 degrees.

Prep the steak
1) Don't even think of cooking $20/lb tenderloin.  The coolest thing about sous vide is that inexpensive cuts are fantastic.  I even had a guest tell me that a $4/lb round steak was the best steak she ever had!
2) I like to trim the steak so there isn't a lot of visible fat.
3) If you are cooking a roast, slice it into 1" thick slices.
4) Season the steak with a little salt and pepper, or steak seasoning.
5) Seal the steak in vacuum bags and drop into the crock pot.
6) Put the temperature probe inside the crock pot.  If I have more than one vacuum bag, I put the probe between them.
7) Be sure the crock pot is turned on.  Cover the crock pot with a towel for a little insulation.
8) Wait 4 to 8 hours.
9) You'll see the temperature controller cycle on and off, turning the crock pot on and off to maintain the perfect temperature.

Finishing - The only down-side of sous vide is that it doesn't add any "char" to the steak, but you can do that in a separate step.
1)   Remove the steaks from the vacuum bags and pat dry with paper towel.
2) Heat a cast iron skillet good and hot.  Add some butter and sear the steaks for 30 to 60 seconds per side.  Don't over-do it.  You don't want to cook them, you're just browning the outside and adding some char.
3) Serve your guest the best steak they have ever had.

For some more information about sous vide, see Sous-Vide 101: Prime Steak Primer