Kitchen hack: How to cook sous vide without a machine
If you watch any of those fancy cooking competitions, chances are you've heard about (and are dying to try) sous vide cooking. It's a method that involves vacuum-sealing food in a bag and cooking it in a water bath for several hours at a low temperature.
The key is to carefully monitor the heat to gently bring your food to the right temperature without overcooking it. Cooking in a bag locks in the food's natural juices, aroma and moisture. This results in super-flavorful, ultra-tender and juicy, evenly cooked food. Unfortunately a sous vide cooker will set you back at least $300, probably more. But here's a big secret: You don't need a fancy appliance to sous vide.
All a sous vide machine does is adjust the temperature of the water as needed, which you can do yourself. You can DIY this technique with a pot, zip-close kitchen bags, some binder clips (seriously!) and an accurate thermometer.
1. Prepare the water bath
Fill a large, heavy-bottomed pot with as much water as you can without it overflowing when you add your food. If you find later that you've filled it too much, you can always use a ladle or heat-safe Pyrex liquid measuring cup to remove water if you need to.
2. Secure your thermometer
You'll need a high-quality (and by that I mean accurate, not expensive) thermometer throughout the sous vide process. For best results, secure it inside the pot rather than dipping it in periodically. You're less likely to miss a temperature fluctuation this way. I really like a digital thermometer for this method, one with numbers large enough to see from a couple of feet away.
You can secure a thermometer inside a pot of water using a heavy-duty binder clip from the office supply store. Clip to the outside of the pot, and adjust the metal pinchers to support the thermometer. The tip of the thermometer should go through the loop of the pincher inside the pot, while the thermometer itself rests on the other pincher. You'll want to secure it so that the tip is dipped in the water but not touching the bottom (where the heat will read higher because of contact with the burner).
Here's what it should look like, more or less, depending on the kind of thermometer you have (this photo shows a pot of milk, not water).
3. Get the water up to temp
Now bring the water to the temperature called for in your recipe. You'll need to play with your heat settings to get it right. It takes a little trial and error to achieve a steady cooking temperature. You should probably try this for the first time on a day when timing isn't urgent rather than the night of a dinner party.
Make sure your thermometer stays within 2 degrees F (plus or minus) of the desired temperature before you consider the water ready. This means you may need to move the heat setting up and down or even move the pot around on the burner — sometimes if you're having trouble maintaining the exact temperature, sliding the pot partially off the burner will be the sweet spot. This is the most time-consuming part of the process.
4. Seal the food inside bags
Place your ingredients into zip-close bags. I prefer high-quality (thicker) sandwich-size bags because they're easier to handle.
Make sure the ingredients are already cut into individual servings. Some foods, like delicate fish, will be hard to remove and cut as needed after cooking (and it takes longer to cook, which is longer that you have to maintain the temperature). Don't put too many pieces of food together into one bag. The ingredients need some room to move.
To vacuum-seal a bag, submerge it open end-up into water as deep as possible without getting water into the opening. The water will push air outside the bag, and you can just seal it right up — almost as good as a vacuum sealer. I like to use a separate dish of water for this step, but you can use the sous vide water.
5. Cook your food
Place the bagged ingredients into the pot of heated water to cook. I've found that using the extra binder clips from the box to secure the bag to the side helps keep the ingredients submerged better and makes it easier to remove the bags later without burning yourself. The temperature will plummet when you add all the bags, but that's not a problem. Simply bring it back to the cooking temperature by raising the heat gradually (don't crank up the heat, or you may have a lot of trouble maintaining a steady temperature later).
Keep monitoring your temperature. As with heating the water, you want to keep it within 2 degrees F of your ideal. Don't be afraid to remove it from the heat if it goes to high, but do keep an eye on it, and put it back on when it dips (not lower than 2 degrees F below the ideal temperature). If it goes too high or too low for a bit, don't panic; just keep bringing it back to where you need it.
Cook your ingredients according to the recipe's directions, then remove from the water (carefully, because it's hot). Be careful removing tender or flaky fish, because it may fall apart if you're too rough with it. That's another good reason to not overpack it. A good set of silicone tongs skillfully used is very helpful. If the food is meat, make certain that it's come up to a safe eating temperature by using the thermometer to check the actual meat temperature just as you would from the oven.
Some recipes may ask you to sear it before serving. Others may ask you to dress it or garnish it with herbs. No matter what recipe you choose, you'll love the flavor of a good sous vide. For many foods, it's like eating them again for the first time.