I’ve been experimenting with this for a while, but last night’s attempt at cooking a roast sous vide was definitely a success. First, I took the roast and let it dry-age in the fridge for about 3 days, covered with a plastic microwave cooking cover that had holes conveniently punched around the sides to let steam (or in this use, the water vapor) escape. Once it had been dry-aged ala Alton Brown, I placed it in the FoodSaver bag and vacuum sealed it.
Then, I hooked up my slow cooker (which normally cooks food around 200 degrees on low), and hooked it up to a NIST-Traceable Temperature Controller and progammed it for 130 degrees Fahrenheit. The Temperature Controller allows me to precisely control the temperature in the water by cutting power to the slow cooker when it gets hotter than 130. I then filled the slow cooker with water (leaving room for the roast beef), dropped the temperature sensor into the water, and let the water come up to temperature. Once it did, I dropped the roast into the water bath and waited for 3 hours or so. This allowed the entire roast to be cooked to medium-rare, which you can’t really do in the oven; normally the outer parts of the roast are overcooked to medium or well-done, while only the very center of the roast gets cooked to the oh-so-delicious state of medium rare. The other beauty of this sous vide cooking technique is that it’s very forgiving about the exact time that it is in the water bath; if you leave it for longer (say because you’re caught up in hacking some code and don’t want to disrupt your flow), there’s no risk of overcooking it.
When I was ready for dinner, I removed the bag containing the roast beef, and placed it on rack that was suspended on top of a large oven-safe casserole dish, and poured the juices that had been in the bag into the dish. This whole assemblage then went into a 500 degree pre-heated convection oven for 10-12 minutes, so the outside of the roast could be browned and filled with Mallard reaction yummyness, and so there would be a nice fond at the bottom of the dish for gravy making.
After pulling the roast from the oven, I dissolved the fond in some cream, added the juices that came out when I sliced the roast, gave it a quick blender action to make sure it was smooth, and then added a tad bit more cream, Cognac, salt and pepper to taste, and then thickened it with just a touch of cornstarch. (One of these days I’ll have to try it with a roux, but I’m a bit weak in my classical French sauce making skills.)
The result? A very nicely browned crust on the outside, surrounding a vast expanse of perfectly cooked medium-rare cow. Very tasty, and extremely flexible in terms of cooking time.