【Experiment】I tried grilling steak with a cardboard "Eco Solar Cooker" that cooks using sunlight.

A cardboard "eco-solar cooker" that uses only sunlight for cooking without using electricity or gas. I was aware of its existence, but can it really cook? I will check by actually grilling a steak.

Lightweight and compact cardboard eco-solar cooker with water-repellent coating

The item I got this time is the "Eco Solar Cooker (solar thermal cooking device)" developed by Earth Cardboard. Made of cardboard, it weighs 638g and is light enough to be held with one hand. When not in use, it can be folded, making it convenient to carry to the campsite.

Although it is made of cardboard, it has a water-repellent coating, so it can guard against some rain and dirt.

Can be assembled by hand without tools

Let's assemble it while looking at the included instruction manual. No tools are needed; simply insert the four wings into the holes and secure them with the included clips. It's very easy, so once you understand it, you can assemble it without looking at anything the next time.

It is designed to move the front and back wings according to the direction of the sunlight. To secure them, only specific clips are needed, which makes adjustments simple.

According to the manual, to improve cooking efficiency, a black container is necessary. So this time, I prepared a skillet.

Less than 5 minutes after installation: 58℃

Although it's only been about 5 minutes since installation, the center is already heating up. Out of curiosity, I touched the skillet placed inside, and it was already very hot.

When I measured the temperature, it was surprisingly around 58 degrees. By the way, the concrete temperature was 40 degrees, so it seems to be collecting the sun's heat quickly.

10 minutes after installation: 79℃

After leaving it for another 5 minutes, the temperature rose rapidly. Although it's lower than the typical grill temperature, it's reaching a temperature suitable for cooking steak.

Let's quickly start grilling the steak. It doesn't sizzle like when heating on a fire, but... Is it really cooking?

10 minutes after placing the meat: 82°C

And here we are after another 10 minutes. The temperature has risen further to about 82 degrees. Looking closely at the thermometer's gauge, the maximum temperature reached is about 87 degrees. At this temperature, it seems like it should be cooked...

The surface of the steak still looked red, so it didn’t feel like it was cooked, but when I flipped it over, it had grill marks. It is definitely cooked.

I can't believe it can really cook without using fire or electricity. It's exciting, like going back to my childhood.

20 minutes after placing the meat: Is it grilled enough to eat!?

And, ten minutes later. Is the inside of the steak cooked through? If it’s just slightly rare, that would be fine, but honestly, I’m nervous thinking, “What if it’s raw?” So, can cooking really be completed using only sunlight? Let’s cut it in half!

It has been about 30 minutes since the setup, and it looks like a roast beef made with a low-temperature cooking device. It was a steak cut with a lot of red, but it is very tender. The flavor lets you feel the deliciousness of the meat, and it turned out to be much more delicious than I had imagined. This is impressive.

This time I used it for heating meat, but it seems you can also use it for various cooking methods like boiling water or cooking rice. Although it can’t be used when the sun isn’t out, it looks like it could be useful in disaster preparedness scenarios, so having one would be reassuring.

Product Name / Eco Solar Cooker
Price / 1480 yen
Weight / 638g
Size / 505×520×525mm

● Earth Cardboard

Search eco-solar cooker on Amazon