2nd Annual Controls Engineer Holiday Gift Suggestion

Submitted by Eric Byres on Wed, 2011-12-07 16:03

Last year during the holiday season, I discussed the merits and demerits of the Kindle as a potential gift for a controls engineer. If you have not made up your mind on what you would like this year, I am once again putting forward a suggestion, along with my comments, on a gift that just might make your heart sing.

SCADA Security, PID Loops and Tender Meat?

When I’m not developing technology to keep industrial facilities safe, or writing about SCADA security, I enjoy dining on gourmet cuisine accompanied by a nice bottle of wine. You may be surprised to learn that a particularly flavourful form of great food that I have recently learnt to appreciate depends on a PID controller.

This year’s holiday gift recommendation is a sous-vide oven... or for those hard-core controls engineers out there, the parts to build your own.

Sous-vide Steak: courtesy of Not so Humble Pie

Sous-vide, pronounced “Sue-VEED”, is French for “under vacuum” and is the process of cooking food sealed in vacuum packed bags submerged in water at a low, even temperature over a long period of time (up to 72 hours).

The result of this cooking method is tender, juicy meat cooked in its own juices, or a firm yet tender vegetable that has retained all its nutrients. Even tough cuts of meat melt like butter in your mouth… after three days of cooking.

Traditional methods of cooking foods, i.e. using high temperatures, cause the cell walls in food to burst. This prevents the food from being able to reabsorb the liquid in the cooking process.

Sous-vide allows foods including meats, fruits and vegetables to preserve their nutrients and shape while still becoming tenderized. While the “under pressure” method of preparing food has been used in restaurants around the world for decades, personal sous-vide ovens have only been around for a few years.

Buying your own Oven

There are several sous-vide ovens on the market to choose from. They boast easy clean up and gourmet taste. These portable units use a thermal conversion circulator or a thermal circulating water bath to keep the water at a constant temperature.

One thing they all have in common is their cost. These things are not toasters; their prices run upwards of $400. Commercial equivalents have prices in the thousands.

Which brings us to our DIY (Do It Yourself) segment...

Sous-Vide Supreme Oven: courtesy SousVideSupreme.com

DIY - Why Buy when you can Build?

To save money and have more fun with this new form of cooking, I suggest assembling your own sous-vide cooker.

The Internet has plenty of information showing that instead of dropping $400 on a new kitchen appliance, someone with a little know-how (can we say “controls engineer”) can whip up a DIY sous-vide for around $100.

Controller and Rice Cooker: courtesy Auber Instruments

All you need is a crock pot or rice cooker, a PID controller, a temperature probe and a few odds and ends. The accurate temperature control is the essential piece to this project – let your fish drift too far off the desired temperature and your sous-vide salmon will be sous-vide salmonella.

In order for the food to be cooked using the proper sous-vide method, the water must stay a constant and fixed temperature (give or take a degree). As Aaron, a “20-something chemical engineer” explains beautifully in his blog DIY PID Controlled Sous-Vide Using a Crockpot the PID controller is used to regulate the temperature in the water, and uses a feedback loop to minimize temperature deviations.

His article includes charts showing the range of fluctuation of an unmodified crock pot, versus one controlled by a PID loop. Suffice it to say, to impress yourself and loved ones with great food, good temperature control is an essential part of the DIY sous-vide equation. And, what is more fun on a weekend than connecting up a set-up like Aaron’s?

For more information on sous-vide, including shopping lists, templates and guidance, see the Related Links at the end of this article.

Accessorize your Sous-Vide: There’s an App for That

As with most things in life, there is an App for cooking sous-vide.

The app breaks down food into categories and describes how long to “cook” each item.

Once you have built your sous-vide unit, you and your smart phone can figure out the perfect cooking set-point for your first gourmet meal.

Eric Byres looking at the Sous-Vide App on his phone

Screen display of the Sous-Vide App

Now, having spoken as someone who has enjoyed sous-vide cooking in restaurants, rather than by my own hand, I know that it creates delicious food. The thought of building my own sous-vide oven excites my engineering neurons - the only problem is my lack of free time.

Thus, I am taking a few short cuts on my sous-vide technology adventure and borrowing one of the PLCs out of the shop as the controller. This means less time with the soldering iron and more time eating (The controller I picked has a nice little (insecure) web interface - remote monitoring of dinner anyone?). The whole system is still in the test phase so sous-vide turkey for Christmas dinner might be a little optimistic.

Or maybe Santa will just give up on waiting for dinner and I will get one of those $400 gizmos in my stocking. Stay tuned…

I’m curious to know if you have tried sous-vide food, prepared it at home, or better yet built your own oven. Let me know about your experience and whether or not you would recommend a sous-vide book or oven as a holiday gift for a fellow controls engineer.

Enjoy!

Ed. Note: Guess what? Eric received a sous-vide oven under the Christmas tree. Read about his experience with it: Sous-vide Oven turns Control Engineer into Gourmet Chef

Comments

Submitted by Anonymous (not verified) on Wed, 2011-12-07 11:15

Xmas Gift for the Control Engineer

Eric...interesting suggestion on using the rice cooker.

For a future article as a gift for control folks...what about a potato cannon as you have demonstrated to some of us in the recent past? It had very good instrumnetation & control set-up (and it even worked)! Perhaps you can organize the best potato cannon "home built" competition from an instrument and control perspective.

Regards
From a Colleaque from Northern Alberta

Submitted by Eric Byres on Fri, 2011-12-09 13:11

Future Blogs - Building Potato Canons

Great idea - expect to see a blog on the design of potato guns some time in 2012

Submitted by Anonymous (not verified) on Wed, 2011-12-07 21:22

I bought the iPad the slow cooker - Where's the vacuum system

Hi Eric looks like you are not feeding the inner engineer enough core material ;). Wonder if you found anyone that has also developed the home made vacuum seal elements to the rice cooker / crock pot?

Interesting choice of present my suggestion is to find something completely technology devoid and spend some quality time with the family in the snow somewhere ;)

All the best to you, your family and the team.

Ron Southworth

Submitted by Oliver (not verified) on Thu, 2011-12-08 00:40

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