That tiny white block is doing serious physics. This is a carbonation stone, a tool brewers use to dissolve CO₂ into beer efficiently and predictably. The key idea is surface area and mass transfer. The stone is made from porous ceramic, sintered stainless steel, or natural stone, with microscopic pores (often 0.5–2 microns). When pressurized CO₂ flows through it, the gas exits as thousands of microbubbles instead of a few large ones. Why that matters: • Smaller bubbles = much higher surface area • Higher surface area = faster gas–liquid diffusion • Faster diffusion = CO₂ reaches equilibrium sooner This process follows Henry’s Law, which says the amount of gas dissolved in a liquid is proportional to the gas’s partial pressure above it (and inversely related to temperature). Cold beer + high CO₂ pressure + microbubbles = rapid carbonation. Without a stone, CO₂ forms large bubbles that rise and escape before dissolving. With a stone, diffusion happens before buoyancy wins. Same phy...