Four years ago I performed an experiment in which I compared 8 different time and temperature combinations for cooking pork belly sous vide. The result was that my preferred options were 48 hours at 57C/135F and 24 hours at 74C/165F. I had also tried 36 hours at 68C/155F, as recommended by SeriousEats. That was nice, but not as nice as 24 hours at 74C/165F. Some years later I’ve started to sous vide other cuts suitable for braising for 48 hours at 68C/155F with great results and often even better than 24 hours at 74C/165F. And so I was curious how pork belly would fare with 48 rather then the previously tried 36 hours at 68C/155F.

To find out, I cut a piece of pork belly in half and sous vided one half for 48 hours at 68C/155F and the other half for 24 hours at 74C/165F.

Then I reserved the liquid from the bags and tasted both pieces.

At 74C/165F there was clearly more liquid in the bag, which I weighed as 25% of the original weight of the meat, compared to only 18% for the pork belly cooked at 68C/155F. On the photo (68C/155F on the left), you can see that a bit more fat has rendered out of the pork belly at 74C/165F (which floats on top).

The most noticeable was that at 74C/165F the pork belly was almost falling apart when I took it out of the bag, while at 68C/155F it was more firm. On the photo you can see that at 68C/155F the meat is more compact.

Of course I’ve tried both pieces of pork belly as well. It was striking that I could not really tell them apart by tasting them; they were both tender, juicy, and equally delicious. I was a bit surprised that they were so hard to tell apart by tasting, because of the difference in firmness and liquid lost during the cook.

My conclusion? 48 hours at 68C/155F is a great time and temperature combination for pork belly, with as the main advantage that it holds together better, which is easier for handling the meat after cooking it sous vide (e.g. if you want to grill or deep fry it). 24 hours at 74C/165F is just as delicious and takes a day less to cook, but it is prone to falling apart and a bit more of the fat renders out (which you can consider an advantage or a disadvantage, depending on your point of view).