Sous Vide Evaporation: How to Deal With It

Some sous vide recipes require extremely lengthy cooking times of over 24 hours. This inevitably leads to water evaporation in the pot. Lower water levels, in turn, may lead to your food not being fully submerged in water.

So, the question arises – how do you deal with sous vide evaporation?

There are a few ways to deal with your water evaporating when a long sous vide session is called for. These methods include using plastic instead of metal containers, putting a lid on the sous vide machine (which, in all reality, it should already have), using vacuum sealed sous vide bags, and more.

In this article, I’ll explain why sous vide evaporation occurs and what it leads to. I’ll also provide several methods of solving this issue.

Does Sous Vide Cause Water Evaporation?

As we remember from school, water evaporation is a natural process. However, certain factors can speed up this process.

Sous vide cooking creates the perfect conditions for quick evaporation. High temperatures are the leading cause, especially if you’re using a metal pot. Why? Metal isn’t the best insulator.

When water evaporates, it cools down. This happens as molecules with the highest temperature move faster than others and leave the surface quicker. The cooler the surface, the less chance of evaporation. The problem with metal is that it heats up quickly and retains the heat for a long time.

The speed of evaporation depends on factors such as temperature, surface, air pressure, and humidity. Generally, evaporation isn’t an issue in sous vide until you decide to cook something that requires prolonged cooking times.

However, in some cases where high temperature is applied, evaporation occurs very soon.

Why is sous vide evaporation an issue? When food isn’t fully submerged in water, it can cook unevenly.

Often, this can be circumvented by cooking the food a bit longer, but sometimes, even this can’t solve the problem, and the meal is ruined.

Adding more water each time you notice it has evaporated is simply wasting resources and will mess with the temperature of the water bath. Furthermore, the water you add must be boiled, resulting in higher energy consumption.

I’ve got some better ideas.

How Do You Stop Sous Vide From Evaporating?

Now you know why sous vide evaporation arises. But how do you deal with it? Thankfully, I’ve got plenty of solutions.

Use Plastic Containers Over Metal Pots

The first hack is to choose plastic containers instead of metal whenever possible. Plastic is a better insulator, so it doesn’t retain heat as much as metal.

In addition, a colder surface doesn’t let the water evaporate as fast.

However, you should make sure the container you’re using is made of high-quality plastic that withstands extreme temperatures. For example, you can purchase a special sous vide plastic container with a lid and gap for an immersion circulator.

Such containers are better than regular plastic storage containers as they’re BPA-free.

Use a Lid On Your Sous Vide Container

Another simple solution is using a lid. That’s right, a simple lid can solve the whole issue.

One drawback is that the lid may raise the temperature inside the pot. Be aware, as you may overcook the food easily or even ruin it if the temperature is too high.

Let’s not forget that metal is a lousy insulator. You can move the lid slightly so that there’s a gap allowing the hot air to escape.

Use Ping Pong Balls

Now we’ve come to more fun DIY hacks that help to prevent sous vide evaporation. All you need for this method is a few ping pong balls.

Of course, it may be more beneficial to get a plastic container or a lid if you don’t already have them. However, it’s an excellent option for ping pong lovers who have the necessary equipment.

Simply throw ping pong balls into the container so that they cover as large an area as possible. In fact, ping pong balls work even better than a lid, as they’re made from plastic and are therefore an excellent insulator.

As a result, they cool down water, minimizing evaporation rather than simply retaining steam inside the pot.

Use a Vacuum Sealer

Vacuum-sealed sous vide bags also help to prevent this issue.

Although it doesn’t prevent evaporation, using a vacuum sealer helps prevent bags from floating, thus keeping them fully submerge in water. And therefore, less water is required.

Likewise, if you pour more water than needed initially, you won’t have to worry about evaporation.

Try Plastic Wrap or Aluminum Foil

If you don’t have any of the supplies mentioned above, plastic wrap or aluminum foil will do the job.

Wrap the top of the cooking container with the wrap a couple of times, then make a hole for your immersion circulator.

Just like a lid, it keeps the accumulating steam inside the container, preventing evaporation.

There are two issues with this method. The first is that wrap may raise the temperature inside the container. Imagine a greenhouse – that’s basically what happens inside your cooking pot.

The second thing to keep in mind is that wrap may cover the cooling vents of your immersion circulator.

Try Sous Vide Cooking Balls

Finally, here’s an option for those who aren’t a DIY fan but don’t want to create a sauna inside the cooking pot.

You can opt for specially dedicated equipment to fight sous vide evaporation. It can be found on Amazon or similar marketplaces. For instance, you can purchase a set of cooking balls as a ping pong ball alternative.

Their main advantage is that the plastic is 100% BPA-free, while ping pong balls aren’t made with food safety in mind. One major point in favor of such balls to a lid is that they’re suitable for any container shape.

Furthermore, you can regulate the number of balls to control evaporation and temperature. If you fully cover the surface, evaporation will decrease, but the temperature will rise. When you need to drop the temperature, simply remove some balls and let some water evaporate.

In Summary

Now that you know how to deal with sous vide evaporation, you can go even for the most challenging recipes that require lengthy cooking.

I highly recommend using a plastic sous vide container with a lid or sous vide cooking balls.

Although DIY methods work fine, the plastic used in ping pong balls or storage containers may contain dangerous chemicals. Therefore, specially dedicated equipment for this purpose is made following all safety regulations.