Monday, January 12, 2009

Pseudo Vide

Starting the water bath preheat at 170F.

I've been playing around with sous vide techniques for the past year now and while I've found it infinitely fascinating, I realize that it's not something that the average home cook can do at home. First of all, the expense to get into sous vide cooking is quite considerable. I use the PolyScience Immersion Circulator, an amazing piece of equipment that allows you to control bath temperature with 1/10th of a degree. It costs $969 - not an inconsequential sum for the home user.

But that's not all, you also need a vacuum sealer to create the anaerobic environment you want for sous vide cooking. Ideally, you want to use a chamber vacuum sealer, like the Minipack-torre MVS31, an "affordable" chamber vac for $2,085. Again, not an insignificant amount of money for the home cook.

After half an hour at 225F, water temp is 136F.

And since I'm not made of money, it's also rather consequential to me - though I am saving my tips to buy one soon. Instead, I make do with a FoodSaver because it's relatively cheap (mine was $175 at Costco) and will do most of the job that a chamber vacuum will do. The big differences between the chamber and the FoodSaver is the ability for the chamber to control pressure hardness that will allow you to do things like change the texture of fruits and other compressed foods that really doesn't work very well in the FoodSaver. Plus, the FoodSaver, compared to the smallest of chamber vacs, is so compact you can keep in on your kitchen counter.

So I've been thinking: how can we achieve sous vide-like results without the expenditure of up to $3,000?

The biggest factor and advantage of sous vide is the controlled temperature environment of the water bath. It's crucial. For many applications, we're cooking the meat at 58.0C (136.4F). This brings the temperature of the meat to a medium rare within an hour and we can hold it at that temperature indefinitely until the meat has reached the desired texture and consistency. For the tenderloin we made this past Christmas, we sous vide(d) the tenderloin for four hours at 58.0C and then finished with a blow torch. The results were succulent, tender and juicy, with the perfect bright pink interior.

Twenty minutes into the cook, bath temp is at 141F.

We've explored sous vide steak before, and since that time, I've improved on my technique a bit (I hope). If we take a one pound steak, season it then vacuum bag it, we'll cook that steak in a 58.0C water bath for 50 minutes. The result is a beautiful pink interior that's just hard to beat. We can take it out a couple of hours to help break down the fibers but 12 hours would be too long (I found out the hard way).

Sous vide allows us to cook to a certain temperature and then no more. In a 136F water bath, the steak will always and only be 136F. It will not turn grey as it would at 160F. But while it's easy to believe that a 136F steak will always be a 136F steak, there is a point where the meat will start to turn mealy, gritty and dry - all the while maintaining it's wonderful pink coloration.

Holding steady at 141F.

The parameters of our experiment are to use only normal home cooking apparatus. No vacuum sealers and no immersion circulators. How can we achieve sous vide results using pseudo vide techniques?

For this, we're going to take a normal cooking pan (in this case a Vollrath 2" deep 1/2 hotel pan - okay, not exactly your mother's casserole but it's what I had handy), an oven, a Ziplock Freezer Bag and a seasoned steak.

First the steak: I went out to (horror of horrors) Costco and picked up a three pack of New York Strip steaks, about a pound each. Being commercial corn-fed, they're not my usual tasty deliciousness but for our experiment, they would suffice.

Season the steaks with a liberal amount of salt and pepper then place in a large Ziplock Freezer Bag. The reason I'm rather specific is that you want a sturdy and thick plastic bag to minimize the possibility of punctures. Nothing ruins a sous vide cook session than water in your food.

After forty minutes, our pseudo vide steak is ready to come out.

And don't be afraid with the seasoning. Give it a liberal application of salt and pepper. Some of you may be surprised that I don't use more exotic seasonings but I'm one who prefers to let the natural flavors of the meat speak for themselves and I find that the salt and pepper accentuates rather than masks the flavor of the meat.

Using your hands, squeeze out as much air from the bag as you can and then seal the Ziplock 95% closed, leaving just a small gap no bigger than your mouth as an opening. Now, it's time to suck.

Using your mouth, suck the remaining air out of the Ziplock bag until the plastic forms tightly around the meat, creating a light vacuum. Quickly seal the remainder of the Ziplock and make sure the seal is tight, secure and the vacuum remains. If there are any air pockets, open the bag and do it all over again. Be sure to get as tight a vacuum as your lungs can produce.

Pseudo Vide Steak ready for finishing.

Once sealed, refrigerate the steak until it chills to 38F. You can leave it overnight if you wish but don't exceed three days. If you can't get back to it for over three day, freeze it.

When you're ready to begin, take a roasting pan and fill it with warm water. Preheat your oven to 225F. Place water pan into oven.

At home, I'm using a KitchenAid double-stack convection oven. It's nearly new and can hold temperature down to 170F. I started here and after 40 minutes, the water bath was only reading 118F, not nearly hot enough. I realized that while the ambient temperature might be 170F, the water would take a lot longer reaching the same temperature. I needed to boost it faster and raised the temp to 225F. To measure water temperature, I'm using a Fluke 51 Series II thermometer.

Adding the finishing touches with a blowtorch.

After another 20 minutes at 225F, the water temperature had reached 136F. Time to drop the steak into the water. With a cold steak going into the bath, I was certain that the bath temp would dip so we would need to maintain oven temp to recover. While I set the oven timer to 50 minutes, I knew we would have to check the temperature as we proceeded and make cook time adjustments as necessary.

From here, it's just a waiting game. Every fifteen minutes, I would check the bath temp. About twenty minutes into the cook, the water temp reached 141.5F, a bit hotter than I would prefer but not too bad. At that temp, the juices might start to be squeezed out of the muscle fibers. If I couldn't keep it below 140F then we might have to cut the cook time.

As the cook progressed, the water temperature remained roughly the same. Decided to drop the temp to 200F and to cut the cook time by ten minutes. Cook time would be 40 minutes instead of 50.

At fifty minutes, I decided to pull the meat from the water bath. The seals' integrity had not been compromised and the steak had that lightly gray/red exterior color that seems typical for sous vide. There was very little juice in the bag meaning that the steak had maintained most of its' water content and yield.

Finished and ready to serve.

From there, all that was necessary was exterior caramelization. You can simply pan sear both sides of the steak until you get the color you desire. For this test, I decided to avail myself of the blowtorch. Nothing caps a technologically enhanced steak like an open flame from a propane blowtorch. Color to your desires.

But what is the end result? As the cross cut image shows, we were able to achieve a pink interior with very little gray ring on the outer edge. This is ideal. The meat itself was tender, moist and pretty darn good.

I had originally started this project thinking that it would not be possible to achieve a sous vide cooktime because I expected the oven to bring the water bath temperature to its' ambient temperature. As we can see, it takes a considerable amount of time to do that using the convection fan. I expect a non-convection oven to work similarly but take longer in its' water heating cycle.

Pink in the center with two eggs on top. Nice.

Some of the naysayers out there (my friends) said that this method wouldn't be possible because of the imprecise nature of an oven. And while it's true that an oven can and will go through swings in temperature, it seems that this temperature swing is mitigated by the water bath - being that the bath doesn't fluctuate temperature as readily. While it's probably not suitable for sous vide cooking that requires precision to the tenth of a degree (like with soft eggs), it can be utilized for cooking proteins in this manner - and with good results, as long as the cook times are relatively short.

Which brings up another problem. While we've seen that short cook times (under 60 minutes) can utilize this technique, during a long cook session, the water bath will, at some point, equalize to the ambient temperature of the oven, destroying the effect of sous vide cooking. 200F is way too hot for sous vide. So too is 170F - and I realize that most ovens out there won't go down that low. So while steaks are possible, sous vide braised ribs are not, unless you monitor and regulate temperature the whole time, which defeats the convenience of sous vide.

In the end, it was a fun experiment but I think I'll stick with my immersion circulator. Thanks PolyScience.