Sous Vide Equipment Explained: The Three Core Tools
By Dana Cole | Reviewed by Chef Daniel Pryce
Published · Last reviewed · 3 min read
Key takeaways
- Sous vide needs only three things: an immersion circulator, a container or pot for the water, and a way to bag and seal the food.
- The circulator sets and holds the temperature; aim for one that keeps the water within about 0.1°C (0.2°F) of target so doneness is reliable.
- Any heatproof container works if it holds enough water and clips the circulator; deeper is better for long cooks to limit evaporation.
- You can seal with a vacuum sealer or with the water-displacement method using a zip-top bag, so beginners do not need to buy a sealer first.
Sous vide equipment comes down to three core tools: an immersion circulator that holds the water at a precise temperature, a container or pot to hold that water, and bags plus a way to seal them. Once you see what each part actually does, choosing becomes simple. This is the kit I reach for every time, and the thinking behind how to pick each piece.
The immersion circulator
The immersion circulator is the heart of the kit: it heats the water and circulates it so the whole bath stays at one exact temperature. That precision is the entire point of sous vide, because temperature sets doneness and the food can never get hotter than the water around it. A good home unit holds the bath within about 0.1°C (0.2°F) of the value you set, which matters when only a few degrees separate results, for example a steak at 129°F (54°C) from one at 135°F (57°C)1. When I first switched from a pan to a circulator, the thing that sold me was opening the bag to an edge-to-edge medium-rare with no grey band at all.
How to choose: look first at temperature stability, then at the water volume the unit can hold steady, then at how it clamps. Wattage and pump strength decide how large a bath it can heat and keep moving; a stronger unit reaches temperature faster and copes with a bigger container. Treat extra features as optional, the job is to reach a target and hold it. If you are still weighing up the whole approach, see getting started with sous vide.
The container or pot
The container is simply the vessel that holds the water, and almost any heatproof pot or food container works as long as it is deep enough and lets water flow around the food. Most circulators need a minimum water depth to run, often around 4 to 6 inches (10 to 15 cm), with a fill line marked on the unit, so the container has to clear that. A large stockpot is fine for a quick cook. For long cooks I prefer a deeper plastic container, because depth means more thermal mass and slower evaporation over a run of several hours.
How to choose: match the size to what you cook. Too small and the food crowds the bath and blocks circulation; too large and the circulator works harder to heat all that water. Depth beats width for long cooks, since a tall column of water loses less to the surface. Make sure the rim suits your circulator clamp, and leave headroom so the level does not drop below the minimum as water evaporates. A lid, a sheet of foil, or floating insulation balls cut that loss and steady the temperature on long sessions.
The bags and a way to seal them
The last piece is a way to bag the food and remove the air, which you can do with a vacuum sealer or with a zip-top bag using the water-displacement method. Removing air matters because trapped air insulates and can float the bag, lifting food out of the water. The water-displacement method is the beginner-friendly route: seal all but one corner of a sturdy zip-top bag, lower it into the water, and let the pressure push the air out before you close the last corner2. A vacuum sealer pulls a firmer, tighter seal that suits long cooks and freezing; for frozen portions, plan on roughly 50% more cook time than the same food unfrozen2. I started with zip-top bags for a year before a sealer ever earned its counter space.
How to choose: a sealer is worth it if you cook often, batch for the week, or freeze portions; otherwise zip-top bags handle most home cooking well. Either way, use food-grade bags rated for the temperatures involved. The full comparison, including which bags to trust and the displacement technique step by step, lives in sous vide bags and vacuum sealing.
Putting the kit together
With those three tools you can cook anything sous vide, and the rest of the gear is optional refinement rather than a requirement. Clips or a rack keep multiple bags submerged and apart so water flows freely; a lid or insulation balls protect long cooks; a torch or hot cast-iron pan handles the finishing sear, since sous vide adds no browning on its own. Start with the core three, learn the method, and add accessories only when a real cook tells you that you need them.
This guide is general information and one cook’s experience, reviewed by a professional chef. Always follow current food-safety guidance for your situation, and give higher-risk eaters standard safe internal temperatures3.
Frequently asked questions
What equipment do you need for sous vide?
You need three things: an immersion circulator that heats and circulates water to a precise temperature, a container or large pot to hold the water, and a way to bag the food, either a vacuum sealer or a zip-top bag sealed by the water-displacement method. That is the whole core kit. Everything else, such as lids, rack clips, and finishing tools, is optional and added as your cooking grows.
How accurate does a sous vide circulator need to be?
Accurate enough that the water sits very close to your set temperature, since temperature is what sets doneness. Many home circulators hold the bath within about 0.1°C (0.2°F) of target, which is plenty for the few degrees that separate, say, a steak at 129°F (54°C) from one at 135°F (57°C). What matters most is that the unit reaches the temperature and stays there steadily, not how many extra features it lists.
Can you do sous vide without a vacuum sealer?
Yes. The water-displacement method lets you use a sturdy zip-top bag: seal all but one corner, lower the bagged food into the water, and let the pressure push the air out before you close the last corner. It is how most people start. A vacuum sealer is firmer and better for long cooks and freezing, but it is not required. Our guide on bags and vacuum sealing covers both in detail.
What size container do you need for sous vide?
Big enough to hold the water level your circulator requires and to let water flow around the food, with a little room to spare. A large stockpot suits short cooks; a deeper plastic container with a lid suits long cooks because depth slows evaporation. Most circulators need a minimum water depth, often around 4 to 6 inches (10 to 15 cm), so check the line marked on the unit before you fill.
Do you need a lid for the sous vide water bath?
Not for short cooks, but it helps a lot on long ones. Over a cook of many hours, an open bath loses water to evaporation, which can drop the level below the circulator minimum and expose the food. A fitted lid, a sheet of foil, or a layer of floating insulation balls cuts that loss and helps the bath hold temperature. See our water-bath tips for the practical setup.
Is an all-in-one water oven different from an immersion circulator?
Yes. An immersion circulator clips to a container you already own and heats and circulates the water inside it. An all-in-one water oven is a self-contained tub with the heater built in, so it needs no separate container. Both hold a precise temperature; the circulator is more compact and flexible, while a water oven is a single tidy unit. For learning the method, either works the same way.
References
- The Food Lab's Complete Guide to Sous Vide Steak, Serious Eats. ↩
- A Practical Guide to Sous Vide Cooking, Douglas Baldwin. ↩
- Safe Minimum Internal Temperature Chart, USDA Food Safety and Inspection Service. ↩
Written by Dana Cole. Reviewed by Chef Daniel Pryce.
Our guides are written from personal experience and reviewed by a professional chef for accuracy. Read our editorial policy.