At what temperature will the fats on meat render?

According to Amazing Ribs:

130-140°F - Fats begin to melt and render (liquefy). This is a slow process and can take hours.

Note: this is 55-60 C.

The speed of the process will increase with temperature.

It's actually somewhat of a problem, if you're not careful. You will hear people say that you can't overcook something sous vide, and while that might be true with some things, anything that has a lot of fat can actually end up with the fat rendered right out of it. I've left a whole duck in so long that there was no fat left in the breast at all. I had to debone it and put all the meat into the rendered fat and put in the fridge for an ad hock duck confit, which by the way worked out beautifully, but wasn't what I had on the menu. We ended up going out to dinner.

We use sous vide and other circulation techniques in my restaurant's kitchen all the time and here's my conclusion for you:

Previous notes about the melting temperature of duck fat are accurate. However, your cooking method should depend on the result you're after. Thus, I've provided two methods below.

For a MR breast: The first step is to circulate your duck breasts at 131 degrees until the internal temperature reaches 131 degrees. This generally takes about 90 minutes. Once cooked, we properly cool and store our breasts (below 40 degrees) until we are ready to serve them. When it is about 30 minutes before you're ready to eat, pull the breast from the refrigerator and let them come to room temperature (or about 60 degrees). At about 15 minutes before you're ready to eat, sear in a saute pan over medium-low heat until that middle layer of fat renders out and the skin is nice and crisp. This should take about 10 minutes. Turn the breast once, long enough for the flesh side to sear slightly and for the middle of the breast to come back to about 122 degrees (this will be warm in the mouth but will not cook your beautifully circulated meat any further). Remove from the pan and rest five minutes before slicing or serving.

For a more traditional confit: Circulate broken down duck (I like to six-cut mine, two breasts, boned out, two whole legs and two whole wings, bone in) at 150 until the internal temperature in the thickest part of the thigh reaches 150. This should be enough time to render most of the fat, but not all of it. I find that this should take approximately two hours if you start from room temperature, three from cold. At this point, fully cooked, you can cool and store your duck in bag in fat for six months or more. If you're ready to serve, in a medium-hot fry pan sear your pieces on the skin side only until crisp. This will be considerably faster than the previous method and you should be careful and pay close attention to your pan. The skin is easy to burn once it's been fully rendered, much like a piece of chicken.

Good luck & enjoy!

My guess is he used 140°F, for over 12 hours. I have done chicken breast and Turkey breast at a 140?F for less than 4 hours and it was perfect juicy not pink.