Sous vide and pellicle/bark

[bkervick]

Hey all.

I've been into cooking sous vide for a few years now, and finally have the space and legal ability to have a BBQ, so I got a pellet grill for smoking (naturally drawn to the pellet since i'm so used to set and forget immersion circulators). I'm very interested in QVQ and SVQ, since I think I've got a handle on many foods and cuts SV and am just looking for a few additional elements (bark and smoke).

I've been doing a ton of research and am intrigued but also confused by the concept of the pellicle in bark formation. I've read the bark article on here and a few other sources. Essentially, the bark is pellicle + spice crust (dissolved into a glaze by moisture/fat and then dried back into a crust + maillard reactions) + color change from smoke.

The problem is that this usually takes a long number of hours. There are suggestions that acid/salt can help create quicker bark.There are also tips that suggest applying the dry rub in advance and allowing meat to sit for at least a few hours aids in pellicle formation (beyond the normal dry brining benefits).

My questions:
Does a pellicle form on already cooked meat? If I ice bathed the meat after sous vide cook, added rub, and let it sit uncovered in fridge would it create the pellicle? Or would it need to be done before the first cooking step (whether SV or Q)? What's the science on this?

Since meat cooked SV has already lost a lot of moisture and rendered fat, would it be smarter to create a dry rub slurry instead of a dry rub to dissolve those spices to quicken the speed of the glaze forming? Perhaps a slurry of a dry rub + clarified purge (following the microwave stickied tip on this forum) to more closely mimic what happens on the meat's surface?

Normal BBQ features an extended period of low temp to dry out the rub to create the crust. But the time is more about achieving full collagen/gelatin breakdown and fat rendering than about the bark needing to take a long time, right? Since I've already achieved those things with sous vide, would a higher temp (assuming I don't use sugar in my rub), create the bark faster? Or are the chemical reactions specific to that temp range?

[bkervick]

So here were my results from my first SVQ attempt taking some of these ideas into account.

I did a pork shoulder, just salt no rub heading into the bag (not in advance), at 145 for ~36 hours. Removed juices. Ice bathed. Added rub, no salt in rub (similar to Memphis dust, sugar, paprika, etc.). Fridged exposed on rack with rub for about 2 hours. After the 2 hours, the rub had appeared to "set" a bit, but I don't really know what I'm looking for in regards to pellicle. I then used clarified bag juices to mop outside to hydrate rub and make a bit of a slurry.

Smoked 2hr or so on high smoke setting (205-235 ish). Cold day, but probes confirmed cook area temp was accurate. My IT was low for most of the cook and rose very slowly. Had meat probe in middle of meat and near edge, and I was at 75 and 90 for a majority of the time, where even after pasteurizing sous vide and ice bathed I was starting to get worried about food safety (since I hadn't planned to re-pasteurize).. Had the beginnings of bark (something like a rosewood color).

Figured it would be a good time to test a bit higher heat. Had about 30 minutes left before I had to shutdown and take the pork on the road, so I cranked up to 375. Even that didn't budge the IT as far as I hoped. It did help darken the bark, probably some increased maillard reactions. Didn't get to black in only 2.5 hours of total smoke, but did get a nice dark mahogany color. There were a couple spots where the rub was starting to re-hydrate, which probably means I got small spots on the very edge that started to cook past 145 or some internal fat pockets rendered that hadn't previously rendered.

Have attached a picture of the final. Small smoke ring, which is nice for only smoke after. Really nice texture. Wasn't the easiest shred I've ever had on pulled pork, but that's what I was going for at 145. I really like the "shredded but with chunks" texture on a sandwich. Was still fully fork tender, moist, and has a nice pull almost a bit like pulled pork crossed with ribs. Smoke was evident, but not overwhelming, which is nice.

Considering the different variables at play (want cold/moist for smoke, but also dry out the crust and longer period of smoke for bark), I think QVQ is definitely the best option, but a SVQ of start slow with slurry then crank up the temp option (but probably longer than I did for the higher temp, maybe a full hour or two at 325 or something after 2 at 225) makes sense if you're not planning to bring the meat IT above your previous cooked IT. I'd also hopefully plan the rub fridge rest for longer to see if that increases pellicle formation.