Wednesday, January 16, 2013

DIY Sous Vide and the Dorkfood DSV Controller

Slow Cooker and DSV Sous Vide Controller
So for Christmas I received the Dorkfood DSV Sous Vide Controller (thanks Mom!), which at $100 is the cheapest path to home sous vide short of wiring your own PID controller and solid state relay together (something I think many home cooks would shy away from). You still need to buy/own a crockpot or rice cooker to act as the heating element (I got this slow cooker on sale), but that's still well short of the $349/479 that a Sous Vide Demi or Supreme is going to cost you. There are two other devices similar to the Dorkfood controller that I'm aware of that go for about $150: this one from Auber Instruments and this one from Fresh Meals Solutions. While I have not used either of those units, my boss does have the Auber Instruments sous vide controller so I can make some comparisons from talking to him about it.

In terms of general operation the controller worked great and maintained the temperature of the water bath within a few tenths of a degree of the set temperature (based on checking every few hours with my Thermapen). Since the heating element is independent of the controller (i.e. it depends on what rice/slow cooker you buy) this isn't meant as a knock, but you should be aware that it takes a fair bit of time to preheat the water bath. For my setup it was over an hour to get from hot tap water to a temperature in the 140's F. Since sous vide is generally a longer term cooking project this isn't much of an issue unless you really want eggs, burgers, or fish or whatever for dinner that night... in which case you clearly need to take the preheating time into account.

The major flaw of this device... and there is indeed a flaw... is not in how effectively it maintains temperature, but in the fact that the $50 you save on it apparently led to a electromechanical relay being used instead of a solid state relay. This means that whenever the PID controller in the device turns your heating element on or off to maintain temperature... something that can happen once a minute or so... there is an audible click as the electromechanical relay switches. In our tiny Cambridge apartment we can hear it from the living room. For me, it's not enough of an annoyance to feel I need to return it to purchase a controller with a solid state relay (I know from my boss that the Auber Instruments one is silent) but it is something I feel any potential buyer needs to be aware of.

Pork Belly In Bath

One final issue I wanted to touch on in this post is whether or not you need a vacuum sealer to do sous vide. Despite the fact that "sous vide" translates to "under vacuum"... you do not, in fact, need a vacuum sealer to do sous vide. Learned this trick from Kenji when I tried his beer cooler sous vide, but the vacuum part isn't really doing any of the work here as far as cooking or flavor. Ultimately what you really need is 1) your meat and any liquid sealed off from the water bath (so as not to leak), 2) the liquid/meat to stay submerged, and 3) only the bag between the liquid and the water bath. You can accomplish this, however, by simply slowly submerging a standard Ziploc style bag in water as you seal up the top. This forces 99% of the air out and is perfectly functional for sous vide.

Now, there are other reasons for buying a vacuum sealer, and obviously this way you are going to have a substantially greater chance of a leak at the seal... but if the added expense of a vacuum sealer was holding you back then you should be aware that it's not something you truly need. Alternatively you could buy these hand pump + special bags to save money as well.

Now what a good vacuum sealer will do is help prevent spoilage, so if you are going to do a lot of sous vide at once and let it hang out in your fridge for days and days before finishing it off... then a real vacuum sealer is something you are probably gonna want, for piece of mind if nothing else.

Thus ends my mixed review of the Dorkfood DSV Controller, a cheap and finely functioning but somewhat annoying DIY sous vide controller. As you can guess from the pictures I've already cooked something delicious in it, and that post should go up by the end of the week.