Does a Sous Vide Need to Be Preheated?

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Sous vide cooking is simpler than many people think. Moreover, you don’t really need to sit by and watch a sous vide which gives you the liberty of getting other things done while it cooks. Even with all the ease of sous vide cooking one question I often get is, does a sous vide need to be preheated before you can use it?

Does a Sous Vide Need to Be Preheated?

A sous vide needs to be preheated to the desired temperature. The optimum temperature for most recipes is between 133 degrees Fahrenheit and 140 degrees Fahrenheit. This temperature range is good for meats, poultry, and even some vegetables like carrots and asparagus.

A person using a silver stainless pot and a spoon for cooking on an electric stove

Whatever recipe you use, preheating is an essential step as you ensure that when you leave the vacuum-packed plastic bag in the water, the cooking process starts immediately.

While it is not ideal, you can cook small portions of food in water that is still heating up, but it is not recommended. Basically, any food that is in the water adds mass and time to the heating process. You would never throw ice cubes into water you were trying to heat up, so why put a large frozen chunk of meat in?

There is also a food safety concern when putting food in too early. If you have a large piece of cold food like a turkey breast, it is possible that the center of that meat will remain in the danger zone for too long while the water comes to temperature.

How to Preheat Food With a Sous Vide

This cooking style is all about precision, so it is a good idea to learn how to preheat the setup before putting in the meat, eggs, or whatever you want to cook. The constant temperature of this cooking technique is what will make a big difference in the results.

Follow these steps to preheat your sous vide for cooking:

  1. Fill a big pot with hot water
  2. Mount your sous vide
  3. Set the desired temperature
  4. Let it run unti the water comes up to temperature

You can accelerate the preheating process by mixing hot tap water with boiling water. Your goal is to get the water to temperature as fast as possible, then let the sous vide keep it there while your food cooks.

If you are cooking in a cold environment, you can insulate your water bath with towels, styrofoam, wood, or with floats. Sous vide precision cookers are not high energy appliances, often drawing around 100 watts of power (this is less than a 10th of a hot plate).

Because of this, they can’t put tons of heat energy into the water quickly. The more you can help your water come to temperature quickly and maintain that temperature through insulation, the quicker and more efficiently you’ll be cooking.

How Does Sous Vide Work?

Sous vide cooking means to cook vacuum sealed food in a controlled temperature water bath. I must vacuum seal the food to prevent contamination of the water as well as to ensure no air insulation exists impeding the cooking process.

The water bath stores tons of heat energy at the exact temperature I want my food to finish. When you cook food sous vide, the food in the bag can never exceed the temperature of its cooking medium (the water). So, imagine if a steak could never exceed a perfect medium rare – that is sous vide cooking.

What if a Sous Vide Is Not Preheated?

If your sous vide is not preheated, then food will take longer to cook. Worst off, your food might be sitting in the danger zone for bacteria and enzymatic activity, which will spoil your food. The larger and colder your food is going in, the more critical it is to preheat your sous vide.

A woman cooking in a red pot while a man chopping the ingredients in the kitchenA woman cooking in a red pot while a man is chopping the ingredients in the kitchen

Related Questions

Check out some of the most common questions I get about preheating water for sous vide cooking.

Can You Add Hot Water to the Sous Vide?

You can add hot water to the sous vide, but only while preheating. The fastest way to raise the temperature of tap water to the cooking temperature is to mix in some boiling water from the stove. Just make sure you don’t exceed the temperature set on your sous vide, or you will need to wait for it to cool back down.

How Long Does It Take To Preheat?

The preheat time depends on your sous vide model, the initial temperature of the water, and the quantity of water to heat. In general, preheating hot tap water with a consumer sous vide in a 3 gallon container takes 15-20 minutes. If you use the boiled water trick, you can be cooking in under 5 minutes.

Will Ziploc Bags Melt in the Water Pot?

Heavy duty freezer bags from major manufacturers like Ziplock do not melt in sous vide temperature water. I do not recommend using cheap or thin sandwich bags as those do not hold up well to higher temperatures. The bags may not melt, but they get weaker and more pliable (ie, prone to leaks) at high temperatures.


Next time you plan to cook sous vide make sure you preheat your water. Not only is it safer for you and your family, it also means your food will cook faster too. Don’t make the mistake of using cold tap water, and if you are really in a pinch, mix some boiled water in to speed things up.

Nathaniel Lee is an avid cook, drawing on his decades of home cooking and fine dining experience. He is a contributing chef at Mashed, and his recipes and contributions have been featured in Tasting Table, Edible Arrangements, Insanely Good Recipes, and The Daily Meal.