I have made a modified sous-vide setup based on the following excellent instructions which I have not seen mentioned here. Total cost was under $75 for me since I simplified the setup a bit. Temperature accuracy is excellent.
Quick overview of my modifications. I used a 6" deep full size hotel pan I got in chinatown as my water bath and a standard $9 1500 watt water heater element instead of the set of immersion heaters.
Pretty easy once I got all the parts together. Assembled it all over the course of one night. Hardest part was drilling the hole into the side of the hotel pan for the water heater. Luckily my neighbor is an electrician and had a step bit that worked perfectly, took about 45 minutes.
Oh, and the Radio Shack relay mentioned didn't work for me when hooked up to my PID's solid state relay (different PID then used in the link). The switching voltage wasn't enough but eventually got a relay that only needed 5V to switch. Short term I used the internal relay which worked fine, but was noisy and I wasn't comfortable driving that amount of amperage through it.
By using beer cooler, you can reduce the heat output required to maintain a constant temperature. I also wonder if one could substitute a mixer or model boat propeller on the end of a rod and a small motor for the pump?
Actually, what gave me the confidence to use the 1500 watt heating element was when I searched for the PID I was buying on google, I found a lot of links to home-brewers who used these heating elements drilled into the side of big aluminum/stainless steel pots. They were using even higher wattage units to get quicker boil times.
It's great that we can so easily share information between different hobbies, isn't it? :-)
Oh, I also ought to mention one thing regarding the heating element for those who might not be familiar. If I remember correctly the National Electric Code indicates that a constant load (such as a heating element) cannot be more than 80% of the peak load rating for the circuit - which (I think) ends up being 1440 watts on a 15 amp branch.
It's almost certainly safe to operate on a 15-amp circuit, but if one is particularly worried about the letter of the law or insurance coverage if anything unfortunate happens, be sure to run on a 20-amp circuit.
Interesting, I wonder if this is a new development (can't find that in my 2005 NEC codebook). I did run across something else, though, 200.21B2 states that the total load on a single 15-amp receptacle cannot exceed 12 amps, which might also apply.
I guess I'm going to have to go back and re-read the whole section. This concludes the thread-jack. We now return you to the regular discussion.
The mash temperature needs to be pretty exact, and I (personally) find it hard to do fine temperature control with a burner. Even a few degrees variation during mash can favor different enzymes and result in inconsistent starch conversion or an alteration in flavor. I've never had much success trying to keep the temperature that steady for a full hour using a propane burner. That's not to say no-one else has success that way.
Besides that, I use a big 100 quart cooler as a mash tun to help keep the temp consistent which precludes using external heat.
My roommate was just using a burner and a pot to heat the water to the desired temp, and then he placed the hot water in a big insulated cooler, which keeps the temperature extremely stable for the hour or so while the warm water flows down into the sparging system in a second cooler holding the mash, unless I'm just completely confused about the process...
Yeah, if you have a cooler that consistent and adjust your temp for the measured thermal mass of the cooler it would work fine. Mine loses about ten degrees per hour at mash temp, however, so I need to adjust the temp pretty continuously during mash.
Of course, another part of it is just my desire to hack together nifty gadgets. :-)
I'm thinking of building something similar but instead of connecting the heating elements directly install a normal wall outlet and use a longer cable for the temp probe.
This way it would be possible to use a rice cooker as some have used in different projects or you can always plug in the same heating elements you used in your setup.
You pretty much describe exactly what I built. It's all installed in a wooden box I created that sits on my counter, the top has the PID display, on either side is a wall outlet, one controlled by the PID and one direct 120V current for the water pump. The temperature controller is on a long wire that just comes out of a whole I drilled on the front, though you can build the fancy headphone attachment as detailed in the link. All the other wiring is in the box too, including the relay which is nice since it muffles the sound of the relay switching on/off.
I tried using it with the rice cooker I had and the results weren't great. I found the temperature fluctuations too erratic but didn't really investigate too much since my rice cooker was gonna be too small for anything but eggs.
This is an awesome hack, but I gotta point out that the price point on "real" SV he's using is off. It's $400+ if you buy a Sous Vide Supreme. But you can also buy a $40 rice cooker (which is a multitasker) and a $130 PID controller from Auber Instruments.
The only downside to the beer cooler hack, besides the fact that it's not precise enough to do eggs, is that it won't work over very long cook times. It looks like it'll kill on steaks, but it isn't going to work for medium rare short ribs.
More Hacker News on Sous Vide, another topic I seriously will not shut up about, is here:
Auber has great customer service too - the sensor on my PID went bad and when I emailed Auber about it, they FedExed a new sensor to me within minutes.
(it occurs to me though that the cooler insulation might help a lot with "active" SV, and now I need to find a way to PID-control an immersible heater).
Not really, to either interpretation of that question:
(a) There's no crock pot I can think of that controls the temperature of what's in the pot; in other words, fill the pot with water, and there's no crock pot that keeps the water at 130f.
(b) Crock pots are (allegedly) hard to control with PID controllers (that's why everyone uses rice cookers); the "low" setting on the crock pot is apparently still too hot.
It's also getting harder and harder to find crock pots that don't have digital controls, which is a dealbreaker if you want to use a cheap PID controller.
I did this last weekend, it made one of the best steaks that I have ever had in my life.
I used a cheap cooler, so I cranked up the temp by 10 degrees above what I wanted the steak to be at when it finished.
One thing that isn't brought up on the page, you probably want to use a rapid digital thermometer rather than your standard analog meat thermometer, I probably let out too much heat when I checked the temp halfway though.
This reminds me of a staple of my Boy Scout cooking: eggs in a bag. Just crack your eggs into a zip top bag (it must be a freezer bag to handle the temperature), add cheese, or peppers, or whatever you like in an omelet, suck out the air, and put it in boiling water until it’s done. Then, if you eat your omelet straight out of the bag, you have no clean up!
It had never occurred to me then to try to cook anything else in bags, but I'm certainly going to try this out.
Just remember that there's a huge difference between boiling and SV'ing eggs. Boiled eggs sound gross. Boiled steak is gross. You don't want to let the eggs get over 150. Eggs cook fast. Water boils at 212f.
Ah yes, I forgot to mention: watch your eggs very closely, or they turn slimy (which is as gross as it sounds, yes). If you get them out in time though, they taste basically like an omelet cooked in a pan. Then again, I was a teenager last time I did that, so maybe I'd have a different opinion if I tasted them now :)
Any consideration for toxicity? I can't imagine plastic baggies are designed to keep food safe for human consumption when you heat them enough to cook meat.
Home brewers have a very similar problem. When you make beer from all grain, you need to stop the heating at certain temperatures and stay at that temperature for some amount of time to let certain enzymes activate. Using a cooler to maintain heat is fairly standard in home brewing. Very neat.
This is talking about a completely different temperature range. What you meant is “cooking your Ziplock at > 195°F may make it melt, and the effects thereof have not been adequately studied”
That's cool! I'm going to try an omaha steak in my cooler, it is already vacuum sealed so as far as I can see I just throw the steak in the hot water and go have a few cold beverages while it cooks. Mmmmmh.
I don't want to burst your bubble or anything, but you should call omaha steaks and ask them what the USDA grade of their steaks would be if they paid for them to be graded. Combine that with the fact that they are usually frozen and you're not getting a good deal on their meat.
I would be at least a little worried about food poisoning. Cooking salmon at 115 deg F, or beef at 125 deg F or even chicken at 140 deg F is not a high enough temperature to kill off many harmful bacteria and parasites. In normal cooking, the external surfaces of the meat, where most contamination occurs, reach much higher temperatures.
Killing most bacteria is a function of temperature and time. The higher the heat, the less time it has to be at that temperature. The lower the heat, the longer it has to be at that temperature. It's all a numbers game. Nothing is completely safe.
That's not entirely true. If you for instance "cook" meat at 100 degrees you'd end up with more bacteria than you started with. You do need to cook at a temperature that is hot enough to actually kill the bacteria. It's not a numbers game at all, it's understanding a little microbiology.
Nothing is completely safe, but food poisoning is also not fun.
I highly recommend that anyone read this information before attempting sous vide. It outlines the various bacteria involved and the time/temp calculations for various items:
Typically you would sear the fish/beef/chicken before/after for texture, flavor and color. Beef for instance will come out grey on the outside and look unpleasant unless seared (inside is still bright red/pink though).
The bigger risk is the time that the food is left in the danger zone of above 50 degrees and below 125 degrees (don't quote me on those numbers, going off memory). Basically any bacteria present in food in that temp range will start reproducing quickly. I have heard 4 hours as the time limit acceptable to have food in that temp range before being considered unsafe.
Beef is ideal to sear just before SVing, not only does it seal in the moisture, but the most dangerous bacteria on beef is on the surface, and just slapping the beef down in a very hot pan, flipping and removing is enough. This is why you can have a blue steak that is cold on the inside (not in many restaurants however) and cooked on the outside.
Searing your steak before cooking would likely aid in the hacked SV as a lack of vacuum sealing means some moisture may be lost, but searing prevents this. It also protects the average, less experienced, cook from giving themselves a wicked case of food poisoning.
The whole point is that temperature of the medium is unrelated to the temperature of the food.
A raw steak is a steak that reaches UPTO temerature X (about 55C I think) during the cookieng.
So you can put it into a low temp cooking device for an hour on 55C or you can throw it onto a 200C owen and leave it there just enough time for it to heat upto 55C.
It seems like there are a decent amount of misconceptions people have about sous vide cooking. Everyone should have a look at the sous vide primer here http://www.cookingissues.com/primers/
http://seattlefoodgeek.com/2010/02/diy-sous-vide-heating-imm...
Quick overview of my modifications. I used a 6" deep full size hotel pan I got in chinatown as my water bath and a standard $9 1500 watt water heater element instead of the set of immersion heaters.