Front view of the South Bay EcoCore Hybrid Deluxe 12-inch medium plush mattress on a modern grey upholstered bed frame.

Mattress firmness scale for EcoCore Hybrid Deluxe showing a medium-plush comfort level, ideal for side, stomach, and back sleepers.

Infographic of the bio-based soy memory foam features: breathable open-celled foam, renewable resources, and hypoallergenic antimicrobial properties.

Cooling feature graphic for South Bay mattresses highlighting gel-infused memory foam and articulated cuts for a temperature-neutral sleep experience.

Diagram of Individually wrapped steel pocketed coils in the EcoCore Hybrid Deluxe mattress for precise support and enhanced motion isolation.

South Bay mattress quality guarantees including a 10-year limited warranty, CertiPUR-US certified foam, and Assembled in USA seal.

Three-quarter perspective of the 12-inch EcoCore Hybrid Deluxe mattress showcasing the white breathable top and grey patterned side fabric.

High-angle view of the EcoCore Hybrid Deluxe medium plush mattress on a designer platform bed in a bright, modern master bedroom.

Detailed close-up of the EcoCore Hybrid Deluxe mattress cover highlighting the premium quilted sleep surface and grey textured border.

Studio product shot of the South Bay 12-inch EcoCore Hybrid Deluxe plant-based foam mattress against a clean white background.

Top-down studio perspective of the EcoCore Hybrid Deluxe mattress showing the geometric patterned white cover.

Simple 3-step setup guide for South Bay mattresses: unbox, unroll, and sleep within 24-48 hours of expansion.

Patented edge-to-edge support technology graphic for the South Bay mattress, providing 20% more usable sleeping surface.

Graphic illustrating the flexibility of the EcoCore Hybrid Deluxe mattress for use on an adjustable power bed base.

Detailed exploded view of the EcoCore Hybrid Deluxe layers including eco-friendly plush comfort, cooling gel, and hybrid edge-to-edge support.

EcoCore Hybrid Deluxe - Plant Based Foam Patented Edge Support Medium Plush 12 inch Mattress By South Bay

Plush Medium Firm Pillow top Memory foam Hybrid

EcoCore Hybrid Deluxe - Plant Based Foam Patented Edge Support Medium Plush 12 inch Mattress By South Bay

$699.00

$999.00

Save $300.00

Brand:

SOUTH BAY

i Size Guide

$699.00

Only 12 left in stock

Free USA Wide Delivery

10 Year Warranty

Advanced Technology

To begin with, the South Bay EcoCore Hybrid Deluxe Mattress is engineered for sleepers who want both restorative comfort and thoughtful, eco-friendly design. It is a 12 Inch Eco-Friendly Hybrid Mattress that brings together renewable soy-based foam and responsive pocketed coils in a single, beautifully balanced sleep surface.

Next, the feel is best described as cloud-like medium plush comfort. The top layer cushions you on contact, while the support core stays buoyant and responsive underneath. This balance makes it a strong pick for couples, combination sleepers, and anyone who wants softness without sinking too deep.

Moreover, the construction reads like a roadmap of modern sleep technology. A gel-infused memory foam layer delivers advanced cooling plant-based technology at the comfort surface. Beneath it, individually wrapped pocketed coils provide buoyancy, airflow, and motion isolation. A bio-based air foam layer made from renewable soy adds further breathability and is the heart of the plant-based hybrid mattress 12 inch design.

Because of this layered build, you get targeted pressure relief for shoulders and hips, paired with a superior edge-to-edge sleep surface that feels stable from corner to corner. It is also a strong choice as the best 12 inch plush hybrid mattress for side sleepers looking for both contouring and support.

Finally, the EcoCore Hybrid Deluxe is built with CertiPUR-US certified bio-foam and backed by a 10-year manufacturer's warranty. Cloudy Mattress is an authorized South Bay retailer, so you can buy EcoCore Hybrid Deluxe online with confidence, choose financing through Affirm at checkout, and add an adjustable bed, a box spring foundation, or old mattress removal to your order. Shop the South Bay collection today and bring home a luxury, eco-friendly mattress for sale at Cloudy Mattress.

Medium Plush 12 Inch Hybrid Feel

This is a true medium plush 12 inch hybrid mattress, offering a soft, cradling top surface paired with reactive coil support so you sink in just enough without losing alignment.

Plant-Based, Eco-Friendly Construction

Made with bio-based polyurethane foam derived from renewable soy, this mattress delivers sustainable sleep for eco-conscious buyers who want comfort that respects the planet.

Cooling Through Every Layer

A gel-infused memory foam layer and an open-cell breathable foam structure work together to dissipate heat and keep the surface temperature-neutral all night.

Patented Edge Support System

The reinforced perimeter expands your usable sleep area by up to 20%, giving you a superior edge-to-edge sleep surface you can confidently sleep, sit, and stretch across.

Built for Side Sleepers

With contouring foam over individually wrapped pocketed coils, the EcoCore Hybrid Deluxe provides targeted pressure relief for shoulders and hips, making it a strong fit for side and combination sleepers.

Trusted Certifications and Warranty

Built with CertiPUR-US certified bio-foam and backed by a 10-year manufacturer's warranty from South Bay International Bedding.

Key Mattress Benefits

6 Layers
Of Cooling
Comfort

The mattress is wrapped in a soft, breathable cover that pairs cleanly with the cooling foams beneath, giving the sleep surface a smooth, comfortable hand-feel.

This is the first contact layer, designed to cushion you the moment you lie down. It contours gently to your shape and uses cooling gel to dissipate body heat, providing targeted pressure relief for shoulders and hips without overheating.

This layer is the heart of the plant-based hybrid mattress 12 inch design. The open-cell breathable foam structure, made from renewable soy, keeps air moving through the comfort core for temperature-neutral sleep.

The structural core is built from individually wrapped pocketed coils that flex independently, delivering bounce, airflow, and motion isolation so partner movement is barely felt across the bed.

A reinforced perimeter surrounds the coil unit and expands the usable sleep area by up to 20%, giving you a superior edge-to-edge sleep surface that stays stable when you sit on the side or stretch toward the edge.

A firm foundational layer stabilizes the entire build, anchors the coil system, and helps the mattress maintain its shape over years of use.

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Plant-based foam is cooler and I can prove it

I tracked my sleep temperature with a wearable before and after switching. My average sleep temperature dropped noticeably on the EcoCore Hybrid. The plant-based foam breathes in a way petroleum foam doesn't and the coil system adds airflow underneath. The best sleeping temperature I've had on a foam-top mattress.

Edge support extends the sleeping surface

My partner and I both sleep close to our respective edges on a queen. The patented edge support means neither of us has a compressed perimeter to worry about. We each get the full surface of the mattress. For a couple on a queen that usable space difference is genuinely meaningful every night.

Medium plush hybrid is my goldilocks

I've spent years stuck between medium firm being too hard and soft being too unsupportive. Medium plush on the EcoCore Hybrid Deluxe is exactly where I needed to be. The coils give me support and the plant-based plush layer gives me the cushion I want. First mattress I've ever bought where I didn't immediately second-guess the firmness choice.

Eco credentials are legitimate

I researched South Bay's plant-based foam process before purchasing. The partial replacement of petroleum with plant-derived oils is certified and reduces the VOC content meaningfully. The mattress had essentially no off-gassing smell. Sustainable and high-performing. Both things are genuinely true here.

Medium plush runs closer to medium

The mattress is well-constructed and the edge support is excellent. My only note is the feel reads more as medium than medium plush to me. I was expecting a noticeably plusher surface and the plush layer is present but subtle. Not a quality issue just a feel calibration question. True medium sleepers will probably love it as-is. Plush seekers may want to know.

HAVE QUESTIONS?

WE'VE GOT ANSWERS

Designed for deep comfort and better rest, so you wake up refreshed and ready for the day

Yes. The plush gel memory foam comfort layer cushions the shoulders and hips, while the individually wrapped pocketed coils keep the spine supported. Together, they make this one of the best 12-inch plush hybrid mattresses for side sleepers in the South Bay lineup.

Plant-based foam means a portion of the petroleum-based ingredients in traditional foam is replaced with bio-based inputs from renewable plant sources. In this mattress, the foam is derived from soy, which makes it a true plant-based hybrid mattress a 12-inch option that is breathable and eco-conscious.

No, a box spring is not strictly required. The mattress works on any solid, flat foundation, a platform bed, or a slatted base with closely spaced slats. It is also compatible with an adjustable base, which is sold separately. Cloudy Mattress offers an "Add Box Spring with Metal Foundation" option at checkout if you want one.

The Patented Edge Support System reinforces the perimeter of the coil unit so the edges hold their shape under weight. The result is a superior edge-to-edge sleep surface that expands your usable sleep area by up to 20%, so you can sleep, sit, or stretch near the side without rolling off.

Yes. The foams used in this mattress are CertiPUR-US certified bio-foam, meaning they meet strict standards for content, emissions, and durability and are made without formaldehyde, phthalates, ozone depleters, heavy metals, PBDEs, and the restricted Tris flame retardants.

Yes. Cloudy Mattress, an authorized South Bay retailer, lets you lease or finance through Affirm at checkout, so you can spread the cost over time on your terms.

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