As promised in my review of sous-vide equipment, I’m going to write more about sous-vide techniques. This is the first post in a series, that will be in the new categorie “Sous-Vide tips & tricks“.
In cooking we often strive to combine a tender and juicy interior with a crispy and flavorful crust, which is an irresistible combination. Sous-vide is a great way to cook the inside of a piece of meat, making it perfectly tender and juicy, but it doesn’t provide a crust. One of the options for putting a crust on a piece of meat that was cooked sous-vide, is deep frying. (This technique is also interesting if you don’t have sous-vide equipment, but in that case you can only use it for a very tender steak like beef tenderloin.)
The advantages of deep frying for searing meat are that it works well for irregularly shaped pieces and that the crust is more crispy than with other methods. The main disadvantage is that you need a lot of fat to deep fry and that you have to be careful not to overcook the inside. For a larger piece of meat this is less of an issue, but for a thinner steak the core of the steak will be well done by the time a nice crust has formed.
As you can see in the picture, this relatively thin (about 2.5 cm/1 inch) piece of hanger steak is still medium rare on the inside after searing it in the deep fryer. How did I manage that? By first cooking the steak sous-vide, then freezing it, and then deep-frying it in very hot beef tallow (190C/375F). When timed just right, the crust is deep brown, crispy, and flavorful, while the inside is still medium rare. Freezing is that trick that is used here to make this possible. This post explains how to accomplish this step by step.
I started with a beautiful piece of wagyu hanger steak from local wagyu farm Het Koeienhuis. Hanger steak is a so-called ‘butcher’s cut’, a lesser known cut (in Dutch: longhaas, in French: onglet) that has a lot of flavor and can be prepared as a steak if done correctly. This means slicing it against the grain, and removing the membrane that runs through the center. It is still a bit tough when prepared like a steak. You can fix this by cooking it sous-vide for 4 hours at 55C/131F, which will tenderize the meat just enough by keeping it medium rare. (If you use beef tenderloin instead, you can skip cooking it sous-vide and go straight to the freezing part. Please note that beef tenderloin is much more tender than hanger steak, but has far less flavor. And it is more expensive.)
In this case, I removed the membrane and sliced the steak into medallions. I seasoned them with salt and freshly ground pepper.
Then I vacuum sealed them.
And cooked them sous-vide at 55C/131F for 4 hours.
I chilled the bag with the meat quickly in cold water (add ice cubes if needed).
Then I drained the meat and kept the juices to make a sauce.
I patted the medallions dry with paper towels.
Then I put them in a freezer bag and froze them. To freeze them more quickly, I arranged the medallions in a single layer between two cool packs that were already frozen. That way, an hour in the freezer suffices. But you could also freeze them for months if you like. Just make sure they don’t get stuck to each other. (To freeze the meat even more quickly, you could use liquid nitrogen instead if you have access to that.)
For best results the medallions should go straight from the freezer to the deep fryer. So make sure the fat is very hot (190C/375F) and that you have enough fat; I used 3 litres (3 quarts) of beef tallow. Using beef tallow for searing beef has two advantages: it gives the beef an additional beefy flavor, and it has a very high smokepoint (higher than most vegetable oils).
Do not deep fry too much meat at once, because then the fat temperature would drop by too much or the medallions would get stuck together.
I deep fried the medallions for 3 minutes.
You may have to experiment a little to find the right time. After 2 minutes my medallions were still frozen inside. After 4 minutes they were overcooked. 3 minutes was perfect.
I drained the medallions on paper towels to get rid of excess fat. Allow to rest for a couple of minutes before serving; the carry-over heat will continue to cook the inside.
Bagna càuda is a warm dip sauce from Piemonte, made with olive oil, anchovies, and garlic and served with raw or cooked vegetables to dip.