This is more an addendum to the duck confit carnitas post from last week than a full on recipe. The assertion I made at the end of that recipe was that I felt like you could use the same technique for traditional porky carnitas, saving yourself the trouble of tracking down a couple of quarts of lard in the same way that minimal duck fat is required for sous vide duck confit... thanks to the whole "food vacuum sealed in a bag" aspect of sous vide cookery. Indeed, I think you could get away with no fat at all since the reason for using fat is to protect the meat from over cooking... a necessity that is directly obviated by sous vide. However you are going need fat at some point, and since not much fat is going to render sous vide, you have to add it. I feel like putting it in the bag and separating it out of the cooking liquid after the meat is done is easy enough, but you could also just use it at the final frying step.
So I basically just dove into making my own sous vide carnitas without much of a recipe to guide me. The results were pretty good, but not perfect. One mistake I made, which you can see clearly above, was shredding the pork too finely before frying it... which subsequently dried it out a bit. Don't do that. Leave it as distinct chunks for frying. Another possible mistake was my choice of temperature. I did 176° F because Kenji suggested it would be done on the order of 12 hours, which it was and that meant I could have tacos on Cinco de Mayo. Which was nice. But Modernist Cuisine suggests 149°F for 36 hours, which could lead to juicier meat as well.
So with those caveats as to my approach, I still think... at least as a broad outline... this is a good way to go. I basically just followed Kenji's recipe for "No Waste Carnitas" but used 3-4 tablespoons of lard instead of 1/4 cup of vegetable oil and sealed it all in vacuum bag. Put the bag in a preheated sous vide setup set to 176° F and pulled it out the next morning... about 14 hours later.
You end up with perfectly cooked chunks of pork, some great cooking liquid to use in a salsa or glaze, and all of your fat back for frying. I don't know if you can tell here, but the meat definitely wasn't as dry as it appears up top... it was in fact perfectly cooked from what I could tell, so I'm not entirely sure going the 36 hour route is really necessary... but assuming enough of the connective tissue breaks down over that time frame at 149°F then it's theoretically going to give you the more moist end product.
Despite my error in shredding the pork a wee bit too much, the tacos I made from it were still pretty great... and really quite easy. I think with a few refinements... and some testing of longer cooking times/lower temperature... this could be dish I make pretty frequently.