How long does it take for water to freeze? All we have to say is this, you know the internet is a special place when you can find this out. Much like with a lot of the questions that we answer here, you better believe that there’s more than meets the eye when it comes to determining the answer to this question.

Before we even begin to dissect this, let’s point out the fact that everyone has known since their school days. The freezing point of water is 32 degrees Fahrenheit…wait, isn’t it? Okay, not that this article is about when water freezes, but, apparently, scientists have made some discoveries in the past that have complicated the idea of when water freezes.

We bring that topic up just for fun as it’s kind of crazy. Regardless, 32 degrees is still the general consensus of when water freezes, but how long does it take for water to freeze once it’s colder than that? Well, let’s take a look.

Looking at ice cubes and water bottles

Zero Chemistry
Photo by Scott Rodgerson / Unsplash

What we’re going to do is take a look at water freezing in both water bottles and ice cube trays. So, no, this article is not going to look at how long it takes bodies of water to freeze or anything like that. We’re going to look at this question in more of a practical sense and doing that with ice cube trays and water bottles seems like a good way to do just that.

In order to answer the question, we first need to assess some of the factors that affect the freezing time of water. To provide you with a quick overview, the factors are,

  • The size and volume of the water
  • The temperature of the freezer
  • The material being used
  • The Mpemba effect

Yes, you did read that last bullet point correctly. We’re going to talk a little bit about the infamous Mpemba effect as it does pertain quite a bit to what’s being talked about here. Saving that one for last, though, let’s talk more in-depth about those factors.

The size and the volume matter

Indeed, this one’s pretty obvious. When trying to answer the question, how long does it take for water to freeze, it kind of starts there, though. For ice cube trays, it would depend on the individual size of the slots for the ice cubes.

The larger the ice cubes, the longer they’re going to take to freeze. Same principle applies to water bottles as the larger the bottle and more water that’s inside, the longer it’ll take for the water to fully freeze.

The temperature of the freezer being used

This is where the freezing point of water comes into play. Again, the general consensus is that water will freeze when below 32 degrees Fahrenheit. However, your freezer should be much colder than that at all times.

As a matter of fact, the FDA recommends that homeowners keep their freezer temperature at 0 degrees Fahrenheit. Oh, also, when waiting for water to freeze, it’s best to keep the freezer door closed as much as possible.

Each time it opens, all that cold air leaves, and then the freezer has to regulate back to its programmed temperature.

The material being used

Clearly, this isn’t referring to water itself but rather whatever the material of the container is that’s holding the water. Probably the two main materials for most water-storing purposes are plastic and metal.

It’s kind of complicated to choose between the two, however. While metal is going to accelerate the freezing process due to its poor insulation, plastic is probably a more practical choice for ice cubes and water containers, and such (regarding freezing water in them).

How long does it take for water to freeze?

Okay, so before we get into the Mpemba effect, let’s try to actually give a potential answer to this question. Factoring in everything that was just brought up, a standard ice cube tray will probably take anywhere from three to four hours to freeze. Meanwhile, smaller water bottles could take up to two hours to freeze, while larger containers could take several hours to fully freeze.

We know, what’s with the vague answer? As you’ve learned, though, it’s more or less impossible to just provide an answer that always works and move on. Believe us, we wish it was that simple. With all that being said, it’s time to talk about something that can also accelerate the freezing process…or can it?

The Mpemba effect

Have you ever heard of the Mpemba effect? It’s very possible you’ve heard of what it claims before without ever knowing what it was called…as that’s the ballpark that we were in before writing this. It’s a rather simple principle and it claims that water is quicker to cool when its initial temperature is warmer. On the surface, it really doesn’t make any sense at all, and the effect has had people taking sides for years.

There are people, in fact, that have done experiments to debunk the Mpemba effect.

We have no opinion on the matter one way or the other, we just want to mention that some believe that using hot water instead of cold water in the freezer will allow it to freeze quicker.

Expect a little bit of a wait time no matter what

The moral of the story when trying to conclude, “how long does it take for water to freeze” is that a little bit of wait time is going to be required. Freezing water is a process and it can’t be done instantaneously.

It sometimes doesn’t take very long, but the factors listed above will impact the waiting time. So, while you’re waiting for your ice cubes to freeze, why not check out how to stay warm in a tent?

Do you guys see what we did there? Yeah, we know, we’re not as clever and witty as we think. Oh, well, go freeze that water now!