Sous Vide Temperature Controller
Introduction
I wanted to buy Nathan Myhrvold's Mondernist Cuisine and was reading some of the advertisements. One of them mentioned sous vide style of cooking, literally translated from French meaning "under empty" or vacuum. This is a bit of a misnomer as the cooking does not use a vacuum, rather it uses a precise temperature controlled water bath. The food is placed in a sealed bag to prevent water from entering the food.
Unfortunately the commercially available cookers using the sous vide technique are very expensive costing between $2000 and $450. I soon discovered a long, extremely well written article on the Seattle Food Geek website, written by Scott Heimendinger. It shows how to build what he calls a Sous Vide Heating Immersion Circulator for about $75. I was excited! His article was detailed and showed how to build a self contained sous vide cooker, including heating elements, circulation pump, temperature controller and probe. It mounts on the side of the cooking container.
I decided to build one but with some modifications. I did not want to use the heating elements rather I was going to use a steamer, fondue pot, or other hot plate to heat the water. Deleting the heating elements simplified the build, as did not having to attach the unit to the cooking container. I also wanted to make it with components that will tolerate 20 amps since I needed to accommodate the power of a hot plate. Configured this way, I can use it to control our smoker as well.
My instructions for building a sous vide controller are included on another page.
Setup
contributed by Adia:
Put the hot plate and sous vide close together on a flat surface. Then, place a pot of your choice, full of water, on the hot plate.
After that, clip some clothes pins creatively, so that the probe is in the center of the pot and is as low as possible.
Next, place a larger pot (or other item of choice) right side down. Place the pump on top of the pot, so that the pump is placed at a higher elevation than the water level. Place the smaller piece of the pump in the water. Clip clothes pins to the plastic of the pump and the pot so that the plastic is not touching the pot or hot plate.
Plug in the sous vide and then the pump. Also remember to set the appropriate temperature right away.
Now the sous vide is set up properly.
Preparation for Cooking
Most of my cooking is done with a large pot on top of a hot plate. The temperature probe and submersible pump are placed in the pot and the temperature set on the controller. Usually the temperature stabilizes in about 15 to 20 minutes.
Food is prepared for immersion by putting it in a plastic pouch. First the food is placed in the bag along with any flavoring. The most of the air should be removed so the bag with food does not float. This can be accomplished in a number of ways. The most complete way is to use a vacuum sealer. This removes the air and seals the bag. I use double zip lock freezer bags and I make sure BPA is not used in the plastic.
I use a vacuum cleaner and a short section of metal tubing, about one centimeter in diameter. I place one end of the tube in the suction hose of the vacuum cleaner and the other in the opening of the zip lock bag. Turning on the vacuum cleaner sucks most of the air out and then you must carefully seal the bag before the air returns. It may take a couple of tries.
Another way is to submerse the bag in a pot of water, with the opening of the bag just above water level. You can carefully massage the bag to get the bubbles out and then seal the bag before removing it from the pot.
Cooking
There are large numbers of recipes on the Internet. There are also large differences in temperature and cooking times. The best approach is to pick one and then experiment. For example, I like most of my red meet cooked to 58C (medium rare to medium). Time is variable, depending on tender the meat is. For example I cook Filet Mignon for an hour and a chuck roast for two days.
One of the misconceptions is that the time is important, like when grilling. The idea is that meat is cooked when the internal temperature reaches a certain point. Beyond that no further cooking occurs. So a steak is ready in an hour or can be removed after a couple of hours, because in my case, it never goes above 58C! This is why restaurants love sous vide, because a series of steaks can be placed in several sous vide cookers, one for rare, one for medium rare, and one for medium. Then the steak is ready when the order comes in.
Once the steak is ready, it must be seared. This allows the Malliard reaction to take place, enhancing the aroma. I like to use a blow torch but a hot pan can be used to sear the steak.
I have since cooked a bunch of stuff. I have to admit the color, smell, and texture of the sous vide meat took some getting used to. In some cases the results were not pleasing, but I attribute this to the lack of experience and the wide differences in cooking time as recommended by the online sources.
For example, when I started I always seared the red meat. I was not used to the green color and subtle smell differences of sous vide cooking. Now I will sear about half the time.
The cooking times are wildly different when reviewing recipes on the web. I am keeping a diary of my successes and failures and will eventually be able to determine my own cooking times and temperatures. For example, I have cooked two chuck roasts. One was the texture and flavor of a good prime rib, amazing. The second was cooked for 48 hours and was firm, dried, and was lacking flavor.
My fantastic successes include salmon, the one chuck roast, fillet mignon, and corned beef. We recently tried a bit of pork tenderloin and were rewarded with amazing texture and flavor. I have always preferred tender meat to flavor, figuring I can add a sauce. Now I am more willing to try tougher cuts with their included better flavor because I can make them tender.
My granddaughter prepared some garlic cloves in oil and sous vide cooked them for an hour in oil. Amazing. However care must be taken because this is the perfect environment for Botulism, so read about how to prevent this online.
I used it to cook the meat for a Shooter Sandwich.
Thanks and References
My thanks to Scott for showing that it can be done.
One of the concerns about this style of cooking is the killing off of the bacteria. I found this article, "The Microbiological Safety and Quality of Foods Processed by the 'Sous Vide' System as a Method of Commercial Catering", funded by several European Union countries. It shows how correct handling of the food, with the correct temperature and duration, is important.
A search for "Low_Temp_Charts" should lead you to some temperature and duration information.
