The Chemistry of the Barbecue "Stall" - Modernist Cuisine

The Chemistry of the Barbecue “Stall”

MCAugust 30, 2012

The “stall” is widely known among serious barbecuers. Well into cooking, the temperature of uncovered meat stops rising and may even fall slightly before it climbs again. Most barbecue experts say this stall occurs when connective tissue in the meat softens and fat starts to render, which does occur, but it doesn’t cause the stall.

The stall is quite real, but it is not due to softening collagen as the graph below shows. We cooked two briskets side-by-side in a convection oven, which mimicked the air temperature in a smoker, but was much more consistent and thus better suited for the experiment. We left one brisket uncovered (blue curve) and vacuum sealed the other (green curve). Sensors measured the core temperature of each brisket as well as the dry-bulb (black curve) and wet-bulb (red curve) air temperatures in the oven.

The stall clearly occurred in the uncovered brisket 2-4 hours into cooking as the wet-bulb temperature in the oven fell. The stall ended after about four hours because the surface of the brisket had dried out enough that it was above the wet-bulb temperature. The temperature of the vacuum-sealed brisket, in contrast, rose steadily to the oven’s set point in about three hours. Any effect due to collagen or fat rendering would occur in both briskets, but we see the stall only in the uncovered one.

Early in the cooking, the wet-bulb temperature rose as the uncovered brisket evaporated, increasing the relative oven humidity to about 72%. But the humidity then began to drop as evaporation could no longer keep pace with the air venting out of the oven. By the eight-hour mark, the humidity was below 50%, and the wet-bulb temperature was down almost 10 °C / 18 °F from its peak.

The core of the uncovered brisket stalled. In this test, we left the brisket dry, but if we had slathered it with sauce periodically as many barbecue chefs do, we could prolong the stall by keeping the surface wet.

Sous vide cooking is, in our opinion, by far the best way to achieve the perfect cooking rate necessary for great barbecue. We barbecued in two distinct steps: smoking to impart the smoke flavor, followed by sous vide cooking to achieve the optimum texture and done-ness.

Smoking before a long sous vide cooking step has the advantage of proteins remaining intact and able to react readily with smoke. Smoked food continues to change while being cooked sous vide: its pellicle darkens, the rind becomes firmer, and the smoky flavor mellows.

The alternative, of course, is to smoke the food after cooking it sous vide. This also works well, but a longer smoking time is required to develop a robust smoked flavor and appearance. This is because precooking denatures a large fraction of the proteins in a cut of meat or a piece of seafood, which leaves the flesh less reactive to the smoke.

Whichever approach you choose to take and you should try both ways to judge the differences yourself the remarkable texture that is the hallmark of sous vide cooking, and the consistency it brings to smoking, makes it the best way to smoke meats and seafood. Alternatively, you could substitute for the sous vide step a combi oven, CVap oven, or low-temperature steamer.

You can find our recipe for Smoked Dry-Rub Pork Ribs here.

–This post was adapted from Modernist Cuisine. Too see what others think of our pastrami, see the Steven Colbert clip below, and click here to read about what Steven Raichlen has to say on The Barbecue Bible.

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6 Responses to “The Chemistry of the Barbecue “Stall””

  1. Allan McPherson

    Good Morning,

    I am a BBQ chef out of Atlantic Canada (yeah, I know…). I first read this article on the stall last summer. As a restaurant cook the upside to knowing why the stall occurs doesn’t help me in a day to day environment (I actually do a lot of sous vide at home, but it is not practicle for my workplace) save for knowing when to aply the texas crutch.

    That said, it plant a seed in my mind that might be taking root. It had occured to me that there might be a way to short circuit the stall, not as it starts, but at the very beginnig of the cook. I might have hit on something in this regard.

    I was reading some old magazine recipes and was chuckling to myself over the use of mass produced convienice products in recipes. The use of commercial mayo as a slather for chicken and fish, especially seemed gross. Until I realized that commercial mayo is basicly emmulsified oil, stabilized “artificially” and heat stable.
    A layer of oil over the meat to be smoked, oil that would cling and not render or melt off of the meat, should be able to inhibit evapouration.
    I started with a three pound blade, already rubbed, then gave it a smear of mayo. It cooked way faster than I would have expected.

    Anyway I have been playing with this idea, and on a purely anecdotal level seems to avoid a stall, or at least shorten it. I am running a couple of pieces today that I have rubbed with a mixture of demi glace, and roasted marrow bone fat emmulsified with xantham gum. We will see how that goes.

    Just something you might want to play with.