Friday, August 15, 2014

Sous-Vide Series: High Steaks for Cheapskates

A Glorious Marriage of Biology, Technology, Butchery, and Parsimony


The silk-purse-from-sow’s-ear approach to sous-vide has been around a long time: cook a cheap, tough cut of meat long and low enough, and it turns buttery-soft, like an expensive cut.

Not quite Dolce & Gabbana
In this post I’m going to explore how far we can take the idea. The first step is to consider that a cheap cut may be of high quality. Chuck and shins and round are cheap cuts even if they come from artisinally raised, prime, heritage-breed cows. They will cost more than similar cuts from the supermarket, but worlds less than the porterhouses and prime ribs from the same animal. Think $7 to $10 a pound vs. $25 to $70.

The cuts we're most interested in are cheap because they're tough. These cuts generally have a lot of flavor, but require long cooking (traditionally by braising or stewing) in order to be succulent. When cooked by traditional methods, they become moist and tender by virtue of all the rendered fat and gelatin (more on this later) but are cooked well-done—gray and stringy. Our goal here is to get that same tenderness, without cooking the meat past the bright pink perfection of a quality steak.

Some cheap cuts of interest include short ribs, oxtail, cheeks, neck, and brisket. We're going to be looking at chuck (especially the part called the chuck roll, or chuck eye), since it's basically the tough twin-brother of prime rib—it can mimic a rib-eye steak quite convincingly.

Additionally, cheap cuts, if you’re dealing with a whole sub-primal section, can be dry-aged just like expensive cuts. It’s just a less common practice, so the trick is finding a butcher who will do it for you. In New York City or the Bay area, this probably means a few phone calls. Farther afield, you may have to forgo the aging, or else get serious and do it yourself. I won’t cover home dry-aging in this post, because, frankly, it’s a more complex topic than even some butchers ackowledge. I’ve had 4-week aged meat from one butcher that had more intense aged flavors than 10-week meat from another. There are many, many variables to consider and tame.

Why dry age at all? The primary reason is flavor. There’s an intoxicating depth, savor, and funkyness produced by the process. The other reason is texture. Aging allows specific families of enzymes resident in the meat to break down collagen and other proteins, for a tenderizing effect. Even cuts that are already tender benefit. If you haven’t had expertly dry-aged meat, seek it out. It will be one of your more memorable gustatory experiences—I promise.

The rest of the process involves harnessing cooking technology to achieve the best possible flavors and textures.

Case Study: Penobscot Bay, Maine

Suppose you want serve some really delicious steak at a dinner party. To a dozen people. On an island, a 12 hour drive and boat ride away. And where the only electricity comes from a solar panel, the stove burns wood, and the propane fridge struggles to maintain 45 degrees. And your budget is $60.

I had the opportunity to accept this challenge when friends invited a small crowd of us to a private island off the Maine coast. Last year my girlfriend and I made pasta, with clams we dug up on the beach. This year, with the help of a good butcher and a cheap immersion circulator, we decided on the steak experiment.

Sourcing the meat was actually the tricky part. I had to call several shops before finding a butcher who was excited about the project, and who agreed to dry age a prime chuck roll for us. That butcher was Rob DelaPietra. He invited me to his eponymous shop in downtown Brooklyn, where we picked a piece of meat together. He cut off a 7.5 lb. hunk of chuck roll from the rib end. Normal price was $10/lb, and since I was buying in bulk he offered it for $8. Expensive compared with regular chuck, but this was a nicely marbled, prime piece of meat. And he was going to charge nothing for the dry aging. My schedule determined that it would age about 4 weeks, which Rob thought would be about right for maximizing flavor with minimal weight loss.


I paid for the meat and walked away. When the time came, four weeks and a couple of days later, here’s how it looked:

Bring on the funk.

I wish I could better describe the smell. The closest thing I can think of is black truffles … that musky, almost dizzying aroma. I raced it home in a cooler, which lent an air of emergency organ-transplant to the proceedings.

And then the work began. After trimming the desicated crust, there was a half pound of trim, and an additional half pound of weight lost as moisture. This works out to about 13% loss, which really isn’t bad. Final cost of the meat, including loss from aging, was $9/lb. I sliced it into 1.5" and 1.75” steaks.


After trimming.

The trim. 8oz. of nasty deliciousness. Save this. More to come in a future post.

The steaks

On to the cooking and the rest. There were 8 discrete steps:

1: pre-sear

2: package for sous-vide

3: immerse for 1 minute in simmering water, to pasteurize surface

4: pre-cook for 4 hours at 40°C / 104°F

5: cook for 44 hours at 55°C / 131°F

6: chill in an ice-water bath, pack in a cooler, hit the road

7: rewarm in water bath on the stove

8: sear on a hot griddle

Here’s a more detailed explanation of the hows and whys, including commentary on the optional steps.

Note: it’s important to NOT pre-season with salt when doing a long cook. Salting before cooking at these times and temperatures will start to cure the meat, changing its color and temperature to something resembling corned beef. Not what we're after.


1) The pre-sear is completely optional. Many people dispense with it. There is some evidence that meat from grass-finished animals, like sheep and some cattle, will develop unpleasant flavors if you pre-sear. This wasn’t an issue for this piece of meat. The reasons for a pre-sear are to make post-searing faster and easier, and to develop better flavors from the maillard (browning) reactions. This is a controversial point; I’m trusting Dave Arnold and Nils Norén at cookingissues.com, whose blind taste test favored a combination of pre- and post-searing.

Pre-seared.

2) Package for sous-vide. I used ziploc bags, with about 45ml liquid added per bag to displace air. You can use stock or melted butter, but in practice there’s little disadvantage to using flavorless cooking oil, even you’re using the bag juices as a sauce component (a topic for another post). If using a vacuum machine, oil or butter helps keep the steaks from sticking to the bag and getting misshapen as the shrink from cooking. Use just enough to coat the meat.

3) Immerse for one minute in simmering water. This is technically optional, but I strongly recommend it, especially if you’re doing a low temperature pre-cook (next step). The idea is to pasteurize the surface, so spoilage bacteria won’t do bad things. While uncommon, some people cooking low and slow have found green slime on their meat, with the aroma of baby diapers. Spoilage bacteria are rarely harmful, but you probably won't be inclined to test this point.

Do the simmering step carefully, with tongs or silicone mitts, and let the water return to a simmer between bags. Be especially careful with ziploc bags. Simmering water is at the upper limit of their temperature range, and the seal can be quite weak until the bags cool a bit.

4) Pre-cook 4 hours at 40°C. I’m expecting protests over this one. This is indeed a temperature associated with high bacterial growth. Health inspectors without biology backgrounds have done a doubletake on less experimental techniques than this. But it’s safe if you follow step 3. I plan to do a longer post on the the pre-cook. Here’s the basic thinking:

Cooking in a beer cooler modified to fit the immersion circulator. This saves a ton of energy.
The enzymes that tenderize meat during the aging process are most active in this temperature range. Calpain is most active at 40°C; Cathespin is most active at 50°C.

Biproducts of these enzymes are further broken down by a group of enzymes called aminopeptidases. This is the process that creates the aged flavors I’ve been crowing about.  There are several aminopeptidases, each with its own temperature of peak activity. The 40°C point gets the most activity out of the most important flavor enzymes.

In addition, experiments cited by Douglas Baldwin found that pre-cooking in the 50°C range produced off-flavors, quite possibly related to products of cathespin.

Nathan Myhrvold and company, in the Modernist Cuisine books, suggest 45°C as a precook temperature. There are some reasons to favor this. Bacterial activity will be lower than at 40°C, and tenderization should procede more quickly. No one I know of has reported off flavors at this temperature.

However, Myhrvold mentions the precook only in conjunction with tenderizing. At 45°C, the most important flavor-producing enzymes are deactivated or degraded.







Disclaimer! All information on precooking and flavor development is provisional. The graphs were created with very few data points, using common enzyme curve shapes. This data comes from scientific studies that were designed to answer very different questions.* I plan to do a more scientific test to see if a 40°C pre-cook actually enhances aged flavors. Right now I can only say that the science suggests it might, and that the results were freakin’ delicious.

I am confident, however, in the safety of this method. There is much more literature on pathogen growth and death curves than on enzymes. In summary: at 40°C, eColi populations double every 30 minutes. This means that after 4 hours, assuming you started with a pasteurized surface, bacteria levels would still only be 0.0003 as high as on the original raw meat. If you are still concerned about this, let me know, and I’ll post the science and math to support it.


5) The final cook. Time and temperature are the usual topics for debate in sous-vide cooking. I went 44 hours at 55°C (I consider this a 48-hour cook, including the pre-cook). The results were very good, if, like me, you’re interested in pink, medium-rare meat that’s tender.

55°C is the lowest temperature acknowledged by the FDA for pasteurizing beef, but the science shows that you can safely pasteurize meat (eventually) at temperatures as low as 52°C / 126°F. A lower temperature would give a more toothy, rare texture, trading some of the developed beefy flavors for brighter, rarer flavors, and giving slightly more rubbery / slimey fat to deal with, especially on a fatty cut like this. I'd be way of going lower that 54°C / 129°F.

A slightly higher temperature will melt more of the fat, making the mouthfeel of some bites more pleasant.

A shorter cooking time (say, 36 hours) will sacrifice some tenderness for some added juiciness. I may lean this way in the future, but only with a similar piece of good quality, aged chuck.

If you’re unfamiliar with the reasoning behind the low-and-slow approach, it can be summed up as this: the “doneness” of the meat is determined solely by the highest temperature the meat reaches. But the tenderness is determined by both temperature and time. Tough cuts are tenderized mostly by the breaking down of collagen (a tough protein which is abundant in all hard-working muscles) into gelatin (which gives melt-in-your-mouth succulence). We used to think this only happened at high temperatures. Now we know that it happens at almost all cooking temperatures. The catch is that the lower the temperature, the longer it takes. If you want to make a tough cut both tender and pink, you’d better have some time on your hands

If you’re thinking, “wait … just a couple of hundred paragraphs ago you said the tenderizing was done by all those unpronounceable enzymes,” good catch. Some of the tenderizing gets done by those. But they’re innactivated by the time you get to cooking temperatures. Once we’re really cooking, some of the tenderizing gets done by higher temperature enzymes, like collagenase, and others simply by thermal breakdown—think of this as the collagen melting.

The good news is that you don’t have to do anything during all thosse hours. Maybe check in a couple of times a day to whisper encouragement, and to make sure the power hasn’t gone out.

6) Chill in an ice water bath. Important!—unless you're planning to sear and eat the meat immediately. The meat's pasteurized at this point, but hasn’t been cooked hot enough to kill spores, which are the dormant, nearly indestructible forms of anaerobic bacteria like c-perfringes and c-botulinum. Killing these spores requires temperatures only achievable in a pressure-canner. You can't do it through regular cooking, sous-vide or otherwise.

These bacteria are a threat because there’s no oxygen in the bag, and it’s a low acid environment—exactly the conditions that allow them to blossom into active bugs. So the only insurance against a full-body botox treatment is to chill the bags quickly and keep them refrigerated. Once you do so, the steaks could theoretically last many weeks in a properly calibrated refrigerator, remaining both safe and fresh. I prefer not to test my luck, so I don’t go past 2 weeks.

On this trip we faced the added challenge of two day’s travel by car and boat to get the meat to an island. As long as you can find ice along the way, this is no problem. Just keep those bags sealed, and make sure there’s plenty of ice all over inside the cooler. My cooler is only decent quality (not like the more expensive marine coolers) and still I only had to re-up on ice once in two days.

7) Warm for service. A water bath is great for this step, too. You can use an immersion circulator, of course, but you don’t need one. Just use a thermometer to make sure the water doesn’t get above your cooking temperature … you don’t want to wreck the careful work you’ve done. I got a big pot of water up to about 53°C and left it on a warm part of the stove. Did I mention it was a wood stove? I like that the process started with a fuzzy-logic, PID-controlled laboratory circulator, and finished on a spruce fire.

Sous-vide bags on the backburner of the Queen Atlantic.
8) Final sear. You can do this lots of ways: a pan, a blazing hot grill, a salamander broiler, a deep-fryer, even a blowtorch. Generally I think the easiest is a griddle. It’s just a heavy frying pan that happens to be big enough for a bunch of steaks. Dry the meat with paper towels, season with salt and pepper, and give the griddle plenty of time to heat up. Water splashed on it should leap back off. If you have an infra red thermometer, get the surface above 260°C / 500°F.

Put oil on at the last minute. I prefer a refined, high heat oil like safflower or canola. Olive oil can work, but you may not want the flavor, and it seems more likely to scorch or catch fire. Be generous with the oil … it’s the only thing that can conduct heat into the irregularities of the meat.
Sear each side of the meat for a minute or less. You may want to hit each side a couple of times but don’t flip constantly here … this slows the development of a crust.

And that’s it. You don’t have to rest the meat. Resting is about equalizing temperatures, and about letting the juices thicken up a bit so you don’t lose too many of them. But it’s not going to be an issue here, because the searing is so brief. If you’re going to slice before serving, as I did, you can do it right away.

Technically, you should slice across the grain. With meat this tender it’s unimportant. Slice however you like. Just make sure to cut the pieces thick enough that people feel like they’re eating a steak.


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How was it?

Well, I wouldn’t have written all this if hadn’t been worth it. It was among the best steaks I’ve had. And all the competing steaks had cost well over double per pound, and had required real cooking skill (but less knowledge) to prepare.

At least one person at the table said it was the best meat he’d ever had.

Someone else said “this is more tender than fillet mignon,” which wasn’t true, but I appreciated the sentiment. My favorite comment: "this is like eating a baby."

Anyway, I’m seriously happy with this method, and plan to use it again, even just to serve guests at home. It’s best suited to a feeding a crowd, because, dry aging small pieces of meat is wasteful. It’s also more satisfying to feed a crowd, since these methods scale so well. I don’t know any other way to serve a dozen people such perfectly cook steaks, and get each plate to table at the same time, hot. If you use these methods, it’s actually easy.


In an upcoming set of posts, we’ll discuss sauce.


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*Sources on enzymatic tenderizing and flavor development:

Mechanism Involved in the Improvement of Meat Taste during Postmortem Aging

Proteases in Fresh Pork Muscle on their Influence on Bitter Taste Formation in Dry-Cured Ham

Quality Aspects of Muscle Foods (Google Books excerpt)

Sous-Vide cooking: A Review

Myhrvold, Nathan; Young, Chris; Bilet, Maxime; Modernist Cuisine, Vol. 3. P.78; The Cooking Lab, 2011

2 comments:

  1. if you are searing the meat before putting it into bags, wouldn't it kill all the bacteria on it? Why do you need to simmer it for a minute in the bag?

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    Replies
    1. Searing is more than adequate for top and bottom surfaces, but it doesn't reliably heat the edges enough to pasteurize them. If you pre-seared in a deep fryer that would take care of everything in one step.

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