What is the best grind for Aeropress?

The AeroPress occupies a unique middle ground in brewing technology, blending the immersion characteristics of a French press with the pressure-driven extraction of an espresso machine. The common misconception is that there is one 'perfect' setting; in reality, the grind size is a variable that must be calibrated against your contact time. A medium-fine grind is the industry standard because it provides enough surface area for the relatively short brew times (typically 90 seconds to two minutes) to achieve a balanced cup. If you grind too fine, the resistance during the plunge increases, often leading to over-extraction and harsh, bitter notes. If you grind too coarse, the water passes through the puck too quickly, resulting in a thin, sour, or underdeveloped cup. From the producer's perspective, the grind size is the final gatekeeper of the work put into cultivation, processing, and roasting. A consistent grind—achieved through a burr grinder rather than a blade—is essential to ensure that the delicate acidity and sweetness of high-quality specialty coffee are not masked by the uneven extraction of 'boulders' and 'fines.' When brewing lighter roasts, which are denser and harder to extract, a slightly finer grind can help unlock flavor; conversely, darker roasts, which are more porous and soluble, benefit from a slightly coarser setting to prevent bitterness. Ultimately, the AeroPress is a tool for control; treat the grind size as your primary lever to adjust the extraction yield to match the specific density and roast profile of the coffee you are brewing.