Cooking sous vide involves heating food in a plastic bag for a long time at a consistent, relatively low temperature. Sous vide cooking was once the province of fancy pants restaurants, but consumer units of sous vide cookers are now available for home cooks like me.
For those who may never have cooked sous vide, a sous vide cooker is maybe a foot long, with a heater in the bottom and usually a propeller to circulate the water. We have a Sansaire model, which like many consumer models is under $200 – not long ago, you could easily drop a grand on sous vide equipment.
We place the Sansaire in a pot of maybe 10 inches of water, set the temperature (usually very low, under 150 degrees Fahrenheit), and put in the food, which should be in a sturdy plastic bag. Although you can use a regular Ziploc bag, it's best to use a vacuum sealed plastic bag ("sous vide" is French for "under vacuum").
Cooking sous vide, you're able to:
Retain nutrients. Because food is cooked in a sealed bag, nutrients can't escape during cooking.
Avoid over-cooking. Sous vide cooking is very forgiving. Once you set the temperature of the water, the temperature of the food cannot rise above that level. In a conventional oven, the temperatures rise way above the desired level of the food, so, for instance, the outside of steak will frequently be way overdone.
Help food retain texture. With sous vide cooking, you maximize desirable textures in meat and vegetables: you're cooking at low temperatures so meat doesn't get tough and vegetables don't turn to mush. For both meat and vegetables, cooking sous vide provides uniform doneness.
Our first cook with the Sansaire was to prepare "just set" eggs for a salad Lyonnaise. We cooked the eggs at 149.9F for 45 minutes. Eggs already come with their own natural container, so you don't need a plastic bag. Our eggs came out perfectly, the white soft, the yellow custardy. Of course, if you want your egg more or less done, you adjust the temperature/time up or down.
Second cook with the Sansaire was with some gorgeous pork belly I picked up at Carnivore. We vac-sealed the meat and cooked it at 148F for 24 hours. Because the temperature of the meat never rose above 148F, the cells in the meat stayed unbroken and the fat was fluffy rather than hard. Before serving, we quickly browned the bacon in a pan; you can enjoy the belly straight from the sous vide cooker, though without browning it feels a little like eating pork sashimi.
Third cook was with beef. To put the sous vide to the test, I chose flat iron steak, an inexpensive, rather tough cut. My hope was that the slow sous vide cooking process would melt the fat and connective tissue in even this tough looking cut and render it tender and tasty. I marinated the steak in vinegar, olive oil, garlic and ground mustard for 30 minutes and cooked it at 125F for 3 hours. After cooking, I quickly pan fried the meat in olive oil and butter for about 90 seconds per side, just to get some caramelization on the outside. It was very tender.
Overall, we're excited to use the sous vide cooker – it's a new kitchen toy we may actually use, and because it's close to fool proof, perfect for me.