Scientists Grow Mars Bricks From Sand and Yeast, No Furnace Required

The recipe for a house on Mars might start in a brewery. Instead of melting Martian soil in a furnace hot enough to hit 1,000 degrees Celsius, a team of researchers grew the glue for their bricks from genetically engineered yeast, the same microbe behind bread and beer. They mixed it with ordinary sand and gelatin, then used freezing and low-pressure drying rather than high-temperature processing to harden the blend. The result was a solid material strong enough to hold weight, with an estimated processing energy one to two orders of magnitude below representative heat-based methods.

Called MLBM, for Martian living building material, the mixture works because the yeast cells are engineered to grow sticky proteins on their surfaces, some that bond the cells to each other and others that glue them to sand grains. Writing in the journal Chem Circularity, the researchers describe blending it into a gelatin-based liquid and exposing it to Mars-like freezing temperatures and near-vacuum pressure, where it hardens into a strong structural material. Broken pieces can be crushed and reformed into fresh bricks, a kind of built-in recycling that could matter a lot on a planet where nothing gets shipped in twice.

How Scientists Made These Mars Bricks Without a Furnace

Researchers started by genetically modifying a common type of yeast, the same kind used in baking and brewing, to grow sticky proteins on the outside of its cells. Some of these proteins helped the yeast cells bond to each other, while others, inspired by the way mussels glue themselves to rocks in crashing ocean waves, helped the yeast stick tightly to grains of sand.

That modified yeast went into a gelatin-based liquid, which was then mixed with plain sand. After sitting briefly at room temperature, the blend went through a freeze-drying process built to copy Martian conditions: temperatures around negative 55 degrees Celsius and air pressure thinned to nearly nothing. As the water inside froze and then turned straight to vapor, the gelatin formed a porous frame, and the yeast cells locked into its walls, reinforcing it from within.

Once hardened, researchers squeezed and bent the small blocks and beams until they broke, a standard way to measure strength. The best version could handle about 12 megapascals of squeezing force and about 6 megapascals of bending force before failing (a megapascal is simply a unit used to measure pressure). For comparison, its bending strength was reported as up to twice that of a similar lightweight cement-based concrete, and it absorbed energy before cracking about as well as reinforced concrete built specifically for toughness.

A separate test checked whether the mixture could be 3D printed, since any real Mars construction would likely rely on printers rather than hand-poured molds. Using a chamber that could simulate both freezing cold and thin air, the team printed a small beacon-shaped structure under simulated Martian conditions: about 0.01 atmospheres of pressure and negative 30 degrees Celsius. Oddly, the print held together better under those harsher, colder conditions than under a milder but still low-pressure test, likely because the extreme cold kept water inside the mixture from boiling and forming disruptive bubbles.

To test reuse, the team crushed the hardened bricks and rebuilt them using the same recipe and process, repeating the cycle several times. The rebuilt bricks kept a similar strength and stiffness to the originals, and the yeast cells inside stayed alive, confirmed by a glowing marker visible under a microscope.

Why These Mars Bricks Aren’t Ready to Build a Colony Yet

None of this means Mars is getting yeast condos anytime soon. The researchers are upfront that their best-performing formula still depends on gelatin sourced from pig skin, an ingredient that would have to be hauled from Earth, along with nutrients to keep the yeast fed. They also tested a gelatin-free version made purely from a biological binder; it was weaker, but it still held together, hinting at a path toward a recipe that relies less on materials shipped from Earth.

A long list of engineering problems also stands between this lab result and an actual Martian structure. A real habitat needs to hold breathable air in against a hostile outside atmosphere, block radiation, manage dust, and hold up for years, not just survive a handful of lab tests. The researchers describe their material as a possible building block, not a complete, airtight home. The strength numbers, the printing trial, and the recycling cycles are all encouraging, but they remain lab-scale results rather than a mission-ready system.

Its achievement is narrower but real: a possible lower-energy alternative to construction methods that depend on heating Martian material above 1,000 degrees Celsius. Whether or not this exact yeast-and-gelatin mix ends up in a real Martian wall, it points to biology, rather than brute-force heat, as a promising building tool for a place so far from home.

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