Editor’s Note: This is the beginning in a series of posts that my husband wrote about building our sous vide machine. It took 4 tries to get it right. He used some blog posts, an article in MAKE magazine, and bevy of engineers to get this done. He’s culled down everything he learned and added some great additions to things he’s seen to create what will (hopefully) be the ultimate sous vide machine. (Read about the benefits and purpose of sous vide.)
Now, before I let John take over, you should know that this is technical stuff. Super technical. Involves splicing wires, and bending metal, and purchasing electrical equipment. Using a heat gun. That sort of thing. Our office was covered in plastic and metal shavings for awhile.
If you’d rather not read this, that’s cool. This is going to be a multiple part series. This post is about where John got his instructions and how he deviated. He also includes a helpful tip on how to NOT burn your house down (useful!), what parts he used and where he got those parts.
So what I’m saying is, this series will be awesome if you want to build a sous vide machine or are a big fan of John (who isn’t?). But if that’s not your thing, hang tight. We’ve got more recipes and stories about dogs coming up too.
Homemade Immersion Circulator: Version 4
I modeled my immersion circulator after Seattlefoodgeek’s blog post: http://seattlefoodgeek.com/2010/02/diy-sous-vide-heating-immersion-circulator-for-about-75/
First off, don’t be sucked in by the $75 price tag. You should make this for the pleasure of making something useful. If you’re lucky enough to have all the tools you need, which is a big if, then the first one might cost you around $75. But, after your first three machines melt down, and you have to build a fourth, you’re looking at $75 x 4. This blog post – for what it’s worth – is meant to keep your version one machine functioning a lot longer than mine and maybe save you from burning down your house.
A Word of Caution: when you finish your immersion circulator (and let’s face it with awesome directions like these, how couldn’t you?) always make sure that your water is up to temperature and holding constant before you walk away from it. Some sous vide recipes can call for meat to be cooked upwards of 2-3 days, so there will definitely come a time when you need to leave it alone.
For those times, clear everything out of the way, make sure your circulator is on a GFI outlet, covered, and holding a constant temperature before you leave or heaven forbid fall asleep in what would sure to be a blazing inferno later. When dealing with these cheap PIDs, some of them have a tendency to overshoot their temperatures. If this happens over time all your water can boil away, and if you’re lucky all that happens is that your circulator will melt down and your heating element will burn out. If you’re unlucky, poof! Your house is on fire.
Now on to the good stuff. I’m not going to do a full set of directions here, as Scott’s blog post does a good job, and if you pick up Make Magazine, they have a more detailed set of instructions in the latest edition based on the same blog. Instead, I’m going to focus on the places where my design diverges from the Scott’s version as well as some clarifying points in the blog instructions that I found confusing. I recommend reading the original instructions all the way through and then reading my revisions so that you have a complete picture before you start construction.
There are four main areas where I diverged from Scott’s design:
- The heating element selected (this leads to the construction of a heating element mounting assembly – heat + plastic = goo)
- The relay selection and heat sink (see notes on Solid State Relays + 13 amp load = one hot son-of-a-bitch)
- The addition of a safety float switch
- Aluminum U clamp instead of acrylic
|4 x Nylon hex bolts ¼’’ – 2’’||Home Depot online|
|12 x matching nylon bolts ¼’’||Home Depot online|
|4 x matching nylon washers ¼’’||Home Depot online|
|4 x rubber grommets ¼’’||Should be able to find at Home Depot in-store.|
|3’’x3’’ square of sheet aluminum||At Home Depot, it comes in much bigger sheets. You’ll need to cut it down.|
|1500 watt 120v water heater element||You can find this at Home Depot in the water heater section. It will look like this one at Amazon.com.|
|25A SSR Heat Sink||http://www.auberins.com/index.php?main_page=product_info&cPath=2&products_id=45|
|PID Temperature Controller with SSR output||http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=3|
|Thermocouple||I’m using a PT100, but any thermocouple supported by your PID will work. The auber instruments PID above comes preset to work with a K type thermocouple. You want the probe to be at least 4 inches long, and preferably 6 inches. This one would be a good choice:http://www.auberins.com/index.php?main_page=product_info&cPath=3&products_id=27|
|Aquarium pump (Pico Evolution 400)||Amazon.com|
|On/Off Switch||Just needs to be rated at something higher than 13 amps: Radio Shack|
|Power Cord (6’ long)||Make sure it’s rated for over 13 amps. You can find them at Home Depot.|
|Flat Bar Aluminum 2’’ Wide||Home Depot online|
|Self-Adhesive Rubber Bumpers||Amazon.com|
|2x Nylon bolts 1 inch x ¼’’ with matching washers and nuts||Home Depot or Lowes|
|Clear acrylic case 4’’x4’’x7’’||I used this one from Target. In the store they sell them individually. You want the middle-sized one at Target.com.|
|2x Nylon bolts 1/8’’ x ½’’ with washers and nuts||Home Depot or Lowes|
|1/8’’ x 2’’ brass pipe nipple||Home Depot online|
|1/8 In. Brass FIP Coupling||Home Depot online|
|1/8’’ Flowline Float Level Switch||Amazon|
|Plastic Epoxy||For gluing the aquarium pump and the J-clamp.|
|Hot Glue||For gluing the power cord and a few other places.|
|Silicone Caulk||For sealing the holes on the bottom of the enclosure.|
|16 gauge wire||Several feet for all the internal wiring.|
|Polycarb Food Pan and Lid||Amazon.com|
Next time, we begin construction!