Simba's most sustainable mattress is miles better than luxury hotel beds - it's all I want to sleep on

I remember when Simba first launched their Earth range: a dreamy trio of sustainable mattresses designed for eco-conscious sleepers who don’t just count sheep, but care about the planet too. Each one is crafted with natural materials and built to be fully recyclable, which instantly piqued my interest. So when I finally got the chance to snooze on the most luxurious model in the collection, the Simba Earth Apex Mattress, I practically leapt into bed.

Having just moved house, I saw it as the perfect moment to reset my sleep routine. I've always believed in investing in the best cooling mattress I can find (a must when you' can be a hot sleeper like me), and this one ticked every box, from breathable British wool to over 5,000 pocket springs. The promise it makes is for cooler, comfier, deeper sleep. And I have to say, Simba delivered.

We all know a mattress is a big purchase, but with a generous Simba sale, you can thank me later. My partner and I are total opposites when it comes to sleep, but this mattress rose to the challenge. Now, I actually dread sleeping anywhere else. From the first night, it was lights out, toss-and-turns gone, and dreams well and truly unlocked.

Simba Earth Apex Mattress Specifications

What's inside the Simba Earth Apex Mattress?

Simba is one of the best mattress brands you'll find when it comes to transparency and communication with what's inside their mattress. Whilst there are some technical terms that might have you scratching your head, it doesn't take much reading to make sense of them. If you want a layer-by-layer breakdown of what's inside the Simba Earth Apex Mattress, snuggle up. I've got it what's inside and why it's there:

• Cover: Plant-derived viscose damask with invisible tufting for a soft, breathable, and smooth surface
• Upper Comfort Layers:
  • Silk & Cashgora wool blend: Provides sumptuous cushioning, breathable and luxurious
  • British wool layers (3–5 layers) for natural insulation and temperature regulation
  • Hampshire wool layer adds support and shape retention
• Microcoil Aerocoil® Layers:
  • Titanium Aerocoil® springs (approx. 2,500) at the top for body-contouring and airflow
  • High-carbon steel microcoils (approx. 2,500) beneath for added support and cooling
  • QuadCore® steel spring base (~750 coils), grouped in fours and sonically welded, for stable, zoned support
• Pocket-Sprung Support: CoreMAX™ 7-zone, 1,000‑spring pocket core providing full-edge support and spinal alignment
• Tufting & Finishing: Invisible tufting and internal hand-tufting to secure and stabilise all 12 layers whilst keeping them smooth
• Overall Depth & Build: Approximately 30–32 cm with 8 to 12 distinct layers

Who would the Simba Earth Apex Mattress suit?

The Simba Earth Apex has a lot to offer sleepers. The better question would probably be to ask who wouldn't it suit? The whole of Simba's Earth range will appeal to those who are eco-conscious. You've got a mattress packed with wool, silk, hemp, and other plant based materials, which ensure that the mattress is crafted from a fully recyclable construction. That means you can sleep without any planet-guilt on your shoulders.

I knew the Apex would be great for hot sleepers, in part because of the sustainable credentials. Wool is naturally breathable and Simba has partnered that with an open spring structure that really lets air move through the mattress, so you don't end up feeling stuffy and clammy in bed. That being said, you don't lose any of the comforts of softer mattresses. The hand-tufting feels really soft and nice to sink onto, whilst keeping a firm feel to the bed.

What impressed me in a way that I didn't expect was just how versatile this is. I am a stomach and side sleeper and my partner is a back sleeper, which can make finding mattresses a little challenging. This supported both of us really well and we both agreed that the motion isolation was second-to-none. Neither of us stirred when the other moved in the night. Although this is an expensive mattress, once you've invested, there aren't really any compromises.

What is the Simba Earth Apex Mattress like to sleep on?

From the very first night, I could tell this mattress was something special. I’m mostly a side and front sleeper, which usually means I need that sweet spot between support and softness and the Simba Earth Apex gets it just right. It cushions my hips and shoulders without making me feel like I’m sinking into a marshmallow. My partner sleeps on his back and likes something a bit firmer, and he’s been sleeping like a log too. The balance of support and comfort is seriously impressive, and the best part, as I mentioned above, is that we’re not disturbing each other when we move. The motion isolation is excellent, which means no more midnight wake-ups when one of us rolls over.

I've been on holidays and to visit friends since sleeping on the Simba Earth Apex and I've actually found a bit of a problem. This has optimised my sleep so incredibly well that I have become a bit of a snob. I don't get the aches and pains on this in the same way that other mattresses either crush my shoulder (too firm) or make me feel hot and uncomfortable (too soft). I've found myself desperate to climb back into this bed to get my beauty sleep. It's brilliant, but I wish I wasn't such a snob.

Is the Simba Earth Apex Mattress cooling?

My partner is one of those people who radiates heat like a human radiator, so a cooling mattress is non-negotiable in our house. The Earth Apex has this clever open structure and breathable layers that actually seem to work. Even when the weather took a turn and we saw some sunshine and hotter days, neither of us found that the mattress was making things worse. If anything, bed was our sanctuary.

Whilst I can be a hot sleeper, I fluctuate a lot. On the days when I was naturally cooler, and I didn’t feel cold either, which is a first for us. Compared to memory foam mattresses I’ve tried before (which can feel like you’re sleeping in a warm cake tin), this one actually feels fresh and breathable, even during a warm spring heatwave.

Is the Simba Earth Apex Mattress good value?

It’s not the cheapest mattress out there, but when you compare the Simba Earth Apex to other hybrids with similar eco credentials and techy layers, like Emma Luxe or Tempur, it actually starts to look like really good value. The fact that it’s made with sustainable materials gives it that extra feel-good factor, and Simba's sale often offers bundles with pillows and protectors thrown in. For something that’s helped both me and my partner sleep better and stop overheating, I think it’s well worth the price.

If you like the sound of that and you want to go all-in on the luxury, natural experience, Button & Sprung's Southdown Mattress is incredible. It's packed full of pocket springs, all the wool is British and traceable, and you get two tension options for how firm or soft you want yours to be and you can zip and link them to suit you and your partner's sleep habits. I'd argue that it's actually even more cooling than Simba's Earth Apex, but the one that I tested was a lot firmer too.

Should you buy the Simba Earth Apex Mattress?

If you’re a couple who sleeps differently (hot, cold, side, back) this mattress is such a good all-rounder. I’ve never found one that suits both of us so well. It’s comfy without being too soft, cooling without feeling clinical, and it keeps movement to a minimum (which my sleep-deprived self really appreciates). Add in the sustainability angle and the fact that it feels properly premium, and I’d say it’s a big yes from me. If you’re on the fence, try the trial period, but I honestly don’t think you’ll be sending it back.

How we test mattresses

At woman&home, we have a rigorous process for how we test mattresses. All of the reviews that you read come from me, our experts, and people who have been cherry-picked to choose the mattress that will tackle a sleeper's grievances.

Before we write a review, our experts have slept on the mattress for at least two weeks, normally more. That's because physiotherapists say that it takes two weeks to notice a change, so we want to be sure that we cover every aspect of the mattress you're sleeping on. In the case of the Simba Earth Apex, I have been sleeping on this since March, so it's had an extended test through the seasons.

When testing, I think about all the key factors: is it comfortable, is it cooling, does it transfer motion? Every aspect will be different for various sleep styles and bodies, so I make sure to be specific about who it would suit and why, I'll also give you context of whether the mattress is good value. If you want to find out more, you can visit our dedicated page for how we test mattresses.