The foam in your mattress is essential to the feel of your bed. Not only does it impact your overall sleep quality, but it may also affect your overall health. Sometimes, foam is made with toxic chemicals -- not something you want to sleep on each night. Some of the biggest brands in the mattress industry create non-toxic foam. Here's what makes them different and why it matters to you. 

Last month, I had the opportunity to tour the 3Z brand mattress factory in Glendale, Arizona. One of my fellow mattress experts and I walked through the 600,000-square-foot facility with the CEO and learned how 3Z makes all of its beds -- from six unique brands -- in-house. Some of the most well-known mattresses from 3Z include the Brooklyn Bedding Signature Hybrid, Helix Midnight Luxe, Leesa Sapira Chill Hybrid, Nolah Original 10", Birch Natural and Bear Elite Hybrid. We set out to learn how a factory that produces six different brands makes each bed feel distinctive.   

Read more: Best Mattress

How does foam differ?

One of the main reasons one bed may feel different from another is the type of foam used. For example, the Tempur-Pedic Breeze Pro mattress feels drastically different from the Nolah Original 10". While the Medium model of the Breeze Pro is also slightly firmer than the Nolah Original, Tempur-Pedic uses dense memory foam in its mattresses. The foam in the Nolah Original is neutral polyurethane foam (made at the 3Z factory). This type of foam is lighter and more forgiving -- meaning that it doesn't leave you feeling like you're stuck in the mattress. Poly foam is still pressure-relieving, but it makes you feel like you're sleeping more on top of the mattress than too within it.  

All-foam beds, like the Nolah Original, are constructed with multiple layers of foam -- each slightly different. Some foam layers are firmer and used for support, while others are comfort layers and allow for pressure relief. The chemical makeup of the foam determines its density, firmness and feel. 

What are the different types of foam used in mattresses?

Besides polyurethane foam, other different types of foam include:

• Memory foam
• Gel memory foam
• Copper-infused foam
• High-density foam
• Latex foam

Read more: Guide to Mattress Types: Materials and What to Consider

How is foam made?

Believe it or not, making foam is a similar process to making a cake. In short, you add the ingredients, mix and watch as the product rises. While the chemistry behind foam isn't quite as simple as baking, this analogy breaks down the foam pouring process in easy terms. 

When Owen and I observed the process, it felt like we were in a How It's Made episode. We were as close as someone could get; we quite literally could have reached out and touched the liquid pouring onto the conveyor belt. 

In layman's terms, John Merwin, 3Z's CEO, describes the foam pouring process as "mixing liquid chemicals in precise ratios." Once these chemicals are combined, they react and rise as the foam is carried down a conveyor belt. 

"This mixture is carefully monitored to ensure uniformity and quality as it rises and cures into a solid foam block," Merwin says. While it takes only mere minutes for the new foam to rise, it takes several hours to fully cure. Once the foam is solid, it's then cut into exact layers to be used in any of 3Z's mattresses. 

If you, like me, thought that the color of a foam determined its feel… that's actually false. At the factory, we were told that the reason one piece of foam is gray, for example, and another is blue is to simply tell them apart.  

It's also important to note that 3Z's foam is CertiPUR-US certificated. This means that the foam is safe, fiberglass-free and made without toxic chemicals such as "ozone depleters, formaldehyde [or] heavy metals." It also means that the foam with this certification "meets stringent standards for content, emissions, and durability," Merwin says. 

The only other foam certification is GOLS (Global Organic Latex Standard), but this only applies to latex foam. 3Z does have beds that contain GOLS latex foam (i.e., the Birch Natural), but that isn't made in-house. The process of making latex foam is very different from polyurethane pouring; it requires certain raw materials, specific procedures and machinery.    

Video: Foam pouring at the 3Z mattress factory

Watch my fellow mattress expert, Owen Poole, and me explore the 3Z factory and understand how they make its foam. 

3Z mattress foam

I have tested more than 50 mattresses over the years, and some of the beds from 3Z are among my favorites. I largely credit that to the materials it uses; mainly the foam. 

3Z is unique in that not many mattress brands in the US pour their own foam or, let alone, own a factory that makes its beds in-house. Merwin says, "Our foams are crafted with meticulous care and attention to detail. What sets our foam apart is that it's poured in-house, giving us full control over the quality of the final product." He continues, "This also allows us to create new foam variations that are exclusive to our brands."

Prior to the trip, Poole and I were very interested to know how 3Z makes their beds distinctive if all the assembled materials are coming from the same place. To this, Merwin says, "The difference in feel among them is due to varying formulations and densities tailored to each mattress model. We adjust the composition and structure of the foam to achieve specific levels of firmness, support, and comfort to meet each mattress's unique requirements."

While 3Z makes a few "universal" foams used in multiple beds and brands, Merwin says that "most of the foam we pour is tailored to each brand," and "each of our brands has a distinct identity… [that] is supported through the materials used to craft each brand's collection of mattresses." 

I walked away from my tour of the factory with both a better understanding of foam and how it impacts the feel and firmness of your mattress. 

Why this should matter to you

If you aren't in the mattress industry like me, watching someone pour foam might not sound like a well-spent afternoon. However, if you value a premium and quality mattress, the making of your bed's materials still applies to you. When looking for a new mattress, make sure its foam is Certi-PUR US certified to ensure your bed is free from toxic chemicals. 

Secondly, the type of foam in your mattress determines the feel and firmness. If you're looking for pressure relief but are a hot sleeper, I recommend gel memory foam. However, if you enjoy the feel of traditional, dense foam, I recommend memory foam beds. Neutral polyurethane foam is a middle ground that seems to please most sleepers.   

If you purchase a mattress from 3Z, you can rest assured that the foam is made in-house, without harmful chemicals and designed specifically for comfort and support. Merwin says, "We are constantly innovating and developing new types of foam that set new benchmarks in the bedding industry."