The NYT piece only covered this briefly. Here is a better discussion of the issue.
Most chefs believe that cooking meat at moderately low temperature (typically 160-180F)submerged in fat - called confit - produces a special flavor and texture profile to the meat.
The classic dish is duck leg confit, which was traditionally used to store duck legs - the legs would be salted, then cooked in fat, and after cooking the fat allowed to congeal around the meat which would tend to isolate the meat from air and help it keep longer.
Sous vide confit puts some fat in the bag with the meat, and that seems to work very well. I experimented a bit with that (see the sous vide thread, and a thread on duck confit). Sous vide confit is a lot less messy than a big pot of fat, and requires less fat - like a teaspoon full per bag rathre than a pot full.
But I wondered if there was really anything to this. I didn't believe that the interior of the meat could actually be affected by being cooked submerged in fat. Fat molecules are way too large to penetrate into the meat.
Some people say all sorts of weird things about how confit might work, like the fat forces juices to stay in the meat, but those are like stories of searing meat to "lock in the juices" which have been shown to be wrong.
So, we cooked both duck legs, and pork shoulder several ways. Traditional confit style, sous vide confit (with fat in bag), sous vide (without fat in bag), and low temperature steaming (in combi-oven or CVAP, at typical confit temperatures). Cooking times and temperatures were the same between all of the tests.
It is easy to see/taste if there is some oil/fat on the meat so after cooking we added some oil or fat to the meat that wasn't cooked confit style.
We had one person handle the cooking and plating, and then we did careful taste tests. None of us (trained chefs and sophisticated eaters) could tell which sample was which better than random.
Our conclusion is that there is no human perceptable difference in cooking via confit. Yes, this flies in the face of tradition, but LOTS of traditional "knowledge" turns out to be wrong when examined in detail.
Some people will have a hard time accepting this. My answer is simple - TRY IT. If have not tried it in a controlled, disciplined and fair way, then there isn't much point in arguing about it, because this is not a matter of opinion or faith - it is a simple experiment.
Edited by nathanm, 14 December 2009 - 08:12 PM.