Sous vide cooking is a relatively new technique to arrive in the home kitchen. Originally from the French for "under vacuum," because it often involves sealing food in plastic, sous vide allows you to cook food gently in an automatic water bath to the precise perfect temperature. The technique has trickled down from experimental fine-dining restaurant kitchens to everyday home cooks precisely because it’s an easy, convenient, and hands-off way to cook. From the perfect seared steak to crème brûlée with the ideal consistency, sous vide makes cooking easier and more foolproof, taking away all the guesswork and giving you back free time. Learn more in our Sous Vide Guide.

Short answer: Yes. Take a look at Is Sous Vide Safe? for more detail.

Not really. Precision and hands-off ease-of-use are two of the most attractive qualities of sous vide for the home cook. Trying to cook sous vide without an immersion circulator forces you to sacrifice both of these attributes. The most effective “hack” for cooking sous vide without a device is to set up a large pot of water on your stovetop, fit it with a thermometer, and fiddle with your burner until you reach your target cooking temperature. But this method is imprecise and requires a lot of babysitting. An immersion circulator accurately controls and maintains the temperature of your water bath so that you don’t have to. Long story short: If you want to cook sous vide, get a device.

No. Vacuum sealers are helpful tools, but not necessary for sous vide. A high-quality zipper-lock plastic bag does just fine.

Covering your water bath container with plastic wrap or a sous vide–specific lid helps to prevent evaporation (and therefore the need to refill the water bath over the course of long cook times). It also helps bring the water back up to temperature quickly after adding ingredients to the bath, which is especially important when cooking delicate foods like Soft-Poached Eggs.

Myoglobin, an oxygen-storing protein and the main pigment in meat, is responsible for the color of your steak. Myoglobin changes hues depending on its chemical environment. Without oxygen, myoglobin is dark purple (think of a raw vacuum-sealed steak). When heated, myoglobin loses an electron and turns brown (think of a cooked sous vide steak). And finally, when exposed to oxygen, that myoglobin turns red (sliced steak).

We love that sous vide allows for a bigger time window for perfectly cooked food compared to most traditional methods. You will notice a lot of our sous vide recipes have ranges for the sous vide cooking time. The idea is that any time within a recipe’s range will yield a great result. The low end of the range gives the ideal result in the least amount of time, and the upper end of the time range is the limit to which that food can be cooked without any negative impact. If a recipe does not have a range, it’s important to hit the exact target time.

You always need enough water to completely immerse the item that you will be cooking sous vide. Keep in mind the principles of displacement—if you are going to be cooking a whole prime rib roast, you don’t want to fill your water bath to the brim. Sous vide devices will either have a minimum water fill-line marked on the device itself or will display an error message if the water level gets too low.

Take it out of the bath, and place it in a second bag. Remove as much air as possible, make sure both bags are sealed, and place it gently back in the bath. Follow our air-displacement method to remove the rest of the air bubbles:

1. Clip bag to container: Clip the corner of the bag to the side of the container with a binder clip, allowing remaining air bubbles to rise to the top of the bag. This step is important because air is a poor conductor of heat and too much of it insulates the food from the hot water bath. Removing air gives the food better contact with the heated water, so it cooks more quickly and evenly.
2. Remove last air bubbles: Open one corner of the zipper and release any remaining air, and then reseal the bag. To prevent cold spots on the food, make sure the bag isn’t touching the sous vide machine or cooking vessel. If cooking with multiple bags, make sure they aren’t pressing up against each other. 

Our displacement method for removing air bubbles is just as effective with liquid. Just be careful not to spill the contents of the bag before you get it in the water!

First, it’s usually not that hot. But if you’re looking to avoid the heat, fill a separate container with cold water and carry out the sealing steps there, and then transfer your bag to the prepared heated water bath. No poached digits! 

We have a “use whatever sinks your boat” policy when it comes to dealing with floating sous vide bags, but here are a few of our favorite methods:     

• Clip a large binder clip to the bottom of the sous vide bag, and then fit a heavy spoon into the mouth of the clip.
• For recipes that call for double bagging, pop a couple of heavy spoons into the outer bag.
• Fill a Mason jar or zipper-lock freezer bag with pie weights, and place it on top of the floating bag. 
• Place an inverted steamer basket on top of the offending floating bag. Then place additional weights, like heavy spoons or pie weights, on top of the basket.

Don’t freak out! Dispose of the water. Thoroughly wash your water bath container. You can gently clean your sous vide device with a no-suds dishwashing detergent (do not submerge the device in soapy water). We also recommend cleaning your device periodically in a vinegar bath. Combine equal parts water and distilled white vinegar in a small pot. Use your sous vide circulator to bring vinegar solution to 140°F/60°C. Once the bath reaches that temperature, the cleaning is complete. This cleaning method also helps remove mineral buildup inside the circulator.

Say it ten times fast: soo veed.