I don’t like to throw away food and when I’m cooking I definitely don’t want to throw away any flavor. So when I brown meat, I always deglaze the pan to make a sauce out of the browned bits that have gotten stuck to the bottom of the pan.
I’ve been cooking sous-vide for over a year now, but until recently I had not figured out how to use the juices that are left in the bag after cooking something sous-vide. Especially when braising meat for two to three days, there can be a lot of juice and since it obviously has a lot of flavor it bothered me that I didn’t know how to use it.
Many sous-vide recipes simply mention “make a sauce from the bag juices”, but don’t tell you how to do this. Above is the juice that I had obtained from braising short ribs for 2 days at 57C/135F. As you can see it is quite a lot.
This is what happens when you heat the juices to make a sauce: the juice will curdle and you get a lot of nasty looking scum. What stopped me from finding the solution until recently was that I wanted to use all of the juices for a sauce. Unfortunately, that is simply not possible as the proteins in there have only been cooked to 57C/135F, so it is unavoidable that they will curdle if you heat it any further.
The solution is simple: first remove most of the scum with a slotted spoon as you usually do with scum on a stock.
Next, line a sieve with paper towels (or a cheese cloth) and filter the juices.
What is left is pure meat juice with a lot of flavor in it, perfect for adding to a sauce.
It is not a problem that the meat has cooled a little while you were doing all of the above steps, because now you can brown the meat and then take the meat out and deglaze the pan with the strained juices to make a quick sauce.
For a fancier sauce, sauté chopped garlic with a few thyme sprigs and a bay leaf for a minute in the fat left in the pan. Deglaze the pan with wine (white wine for white meat, red wine for red meat) and then add the strained juices. Let it reduce a bit over medium heat and then strain. If you like you can make it a bit thicker by whisking in some small pieces of cold butter.