This year, Santa brought a Sous Vide Supreme – a “water oven” that allows one to cook vacuum-packed food at a constant, precise (usually low) temperature.
There are a few reasons to get into sous vide cooking:
- Precision temperature control means no over- or under-cooking. You can cook a perfect soft-cooked egg every time.
- It allows you to cook and hold items at a specific temperature for a relatively long period of time.
- Flavour is captured in the cooking pouch – items can braise in a tiny amount of flavouring, along with their own juices. You don’t lose any of the food’s inherent flavour to the cooking environment, and you can either supplement that flavour with other tastes, or just leave the main ingredient to taste intensely of itself.
- Being able to cook at extremely low temperatures for extended periods of time allows you to produce effects that can’t be achieved through other means of cooking. For example, you can cook tough cuts of meat like brisket or short ribs long enough for them to become super-tender, while maintaining them at a medium-rare temperature.
- It enables you to cook things to the same temperature all the way through, without drying them out. Consider the normal way of cooking a steak: hitting it with high heat and hoping that the centre will reach medium-rare before the outside is charred. You need to work hard to avoid an over-done outside, under-done inside, and toughening or drying out. Even if you do everything right, you end up with varying degrees of doneness. This gets to be more of a problem as you cook thicker cuts, like “baseball” tenderloin steaks and 2-inch thick T-bones for bistecca alla Fiorentina. In a water oven, you can gently bring the steak to a single, uniform temperature and doneness all the way through. If you want medium-rare steak, you set the oven at 135’F, and the steak can never get more done than that. Then just before serving, you blast the outside with some high heat to get that tasty, tasty crust.
This isn’t to say that everything done sous-vide is perfect, or that it’s appropriate all the time: sometimes you want the melding of flavours that a traditional oven braise provides, and sometimes it’s nice to have a leg of lamb that has some rare and some well done meat. Sous vide is just another cooking tool, and I’m enjoying learning to use it.
This year’s New Year’s Eve feast will include cassoulet. And that, my friends, means duck confit: lightly salt-cured duck legs cooked slowly in duck fat until they become succulent beyond belief.
There are a few things about duck confit that lend it to sous vide cooking:
- It needs a constant, low temperature over several hours in order to become tender without seizing up or drying out.
- Cooking it traditionally – in a pot in the oven – requires a heckuva lot of duck fat. Sous vide, you can just vac-pack the legs with a couple of tablespoons of fat, and depend on water to transfer the heat.
For the curing and flavouring, I turned to Michael Ruhlman – the recipe is on his website, but can also be found in his excellent resource, Charcuterie: The Craft of Salting, Smoking, and Curing.
After 48 hours in the fridge, I rinsed the duck legs, patted them dry, and got ready to vacuum pack them with duck fat.
For a good vacuum seal, you need to ensure that the edge of the bag is kept clean and dry. Folding the edge over itself is the easiest way to do this. Plus, you end up with a bunch of bags that look like they’re saying “NOM NOM FEED ME DUCK AND FAT NOW.”
Sous vide cognoscenti have differing opinions regarding the optimal time and temperature settings for confit. They typically range from 165’F to 180’F, and from 8 to 12 hours. As usual, I take Thomas Keller’s advice – in his pioneering book, Under Pressure: Cooking Sous Vide, he recommends 180’F for 8 hours.
Got botulism? No thanks. Unless you're serving sous vide food immediately, you need to plunge it into a 50% ice / water bath and keep it there as long as the guidelines specify – this is a function of temperature and food thickness.
After coming out of the ice bath, one leg went into a hot-but-not-smoking cast iron skillet for 30 seconds each side. I wish I could tell you it came out looking like this:
How did it taste?
Pretty amazing. Definitely on the salty side of fantastic, but for its intended uses – in a salad, and as a cassoulet garnish – it’s great. The texture was unbelievable – still holding together, but falling away into silky strands on the fork. The garlic (which I was skeptical about) ended up being a really special flavour. Robust, but not at all aggressive.
Next time, as someone who likes to eat duck confit as a main course rather than a garnish, I’d probably cut the curing time down to 12 hours or even 6: in Under Pressure, Keller uses a 6-hour cure; Ruhlman, in Charcuterie, advises between 24 and 48 hours. Presumably, the sous vide method intensifies the saltiness.