Not all beds are the same. We went behind the scenes to see how the foam in your mattress is created

The type of foam your mattress is made with can not only affect your overall quality of sleep, but also affect your overall health. Some pennies are made with toxic chemicals that you don’t have to sleep every night. Fortunately, many mattress brands create and use non-toxic foams in their mattresses. Here’s what to look for when shopping non-toxic mattresses and why it should matter to you.

CNET’s sleep team had a chance to tour Brand 3Z Mattress Factory in Glendale, Arizona. During the tour of the 600,000-square-foot facility, we learned from the CEO how 3Z manufactures all of its beds—six unique brands—in-house. Some of the most popular mattresses from 3Z include Brooklyn Bedding Signature Hybrid, Helix Midnight Luxe, Leesa Sapira Chill Hybrid, Nolah Original 10-in, 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: The best mattresses of 2024

How is foam different?

One of the main reasons one bed feels different from another is the type of foam used. For example, on Tempur-Pedic Breeze Pro Mattress feels drastically different than 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 a neutral polyurethane foam (made in the 3Z factory ).Polyethylene foam still relieves pressure, but makes you feel like you’re sleeping more on the mattress than on it.

All-foam beds, like the Nolah Original, are constructed with multiple layers of foam – each slightly different. Some layers of foam are firmer and are used for support, while others are comfort layers and allow for pressure relief. The chemical composition 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 foam
• High density foam
• Latex foam

Read more: A guide to mattress types: materials and what to consider

How is foam made?

Believe it or not, making mousse is a similar process to making a cake. In short, you add the ingredients, stir and watch the product bubble. Although the chemistry behind foam is not as simple as baking, this analogy breaks down the foam pouring process in simple terms.

As Owen and I watched the process, it felt like we were on an episode of How To. We were as close as possible; we could literally reach out and touch the liquid pouring onto the conveyor belt.

In layman’s terms, John Merwin, CEO of 3Z, 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 hardens into a rigid foam block,” says Merwin. Although it only takes a few minutes for the new foam to rise, it takes several hours for it to fully harden. Once the foam hardens, it is cut into precise layers to be used in each of the 3Z mattresses.

If you, like me, think that the color of the foam determines its feel… that is actually false. We were told at the factory that the reason one piece of foam is gray, for example, and another is blue, is simply to tell them apart.

It is also important to note that the 3Z foam is CertiPUR-US certified. This means the foam is safe, contains no fiberglass and is made without toxic chemicals such as “ozone depleting substances, formaldehyde (or) heavy metals.” It also means that foam with this certification “meets strict standards for content, emissions and durability,” says Merwin.

The only other foam certification is GOALS (Global Organic Latex Standard), but this only applies to latex foam. 3Z has beds that contain GOLS latex foam (i.e Birch Natural), but this is not done internally. The process of making latex foam is very different from pouring polyurethane; requires certain raw materials, specific procedures and machines.

Video: Pouring foam at the 3Z mattress factory

Watch my fellow mattress expert, Owen Poole, and I explore the 3Z factory and find out how they make their foam.

3Z mattress foam

I’ve tested more than 70 mattresses over the years, and some of the 3Z beds are among my favorites. I largely attribute this to the materials he uses; mainly the foam.

3Z is unique in that not many mattress brands in the US infuse their own foam or, let alone, own a factory that manufactures their beds themselves. Merwin says, “Our foams are crafted with meticulous care and attention to detail. What sets our foam apart from others is that it is poured in-house, giving us full control over the quality of the final product.” He continues: “This also allows us to create new foam variants that are exclusive to our brands .”

Before the trip, Poole and I were very interested to find out how 3Z makes its beds distinctive if all the assembled materials come from the same place. Of this, Merwin says, “The difference in feel between them is due to different formulas 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 several “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 different identity … (which) is maintained through the materials used to make each brand’s mattress collection.”

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

Why this should matter to you

If you’re not in the mattress industry like I am, watching someone pour foam might not sound like an afternoon well spent. However, if you value a premium quality mattress, the craftsmanship of your bed’s materials still matters to you. When looking for a new mattress, make sure it has foam Certi-PUR USA certified to ensure your bed is free of toxic chemicals.

Second, the type of foam in your mattress determines the feel and firmness. If you are looking for pressure relief but sleep a lot, I recommend gel memory foam. However, if you like the feel of a traditional, dense foam, I recommend memory foam beds. Neutral polyurethane foam is an average solution that seems to appeal to most sleepers.

If you buy a mattress from 3Z, you can rest assured that the foam is proprietary, free of harmful chemicals and designed specifically for comfort and support. Merwin says, “We are constantly innovating and developing new types of foam that set new standards in the bedding industry.”