Surface Area & Agitation

For interaction to occur between water and coffee grounds, there must be contact between the two. This contact depends on the available surface area. The finer the coffee grind, the larger the surface area becomes, because the surface-to-volume ratio increases. The smaller the particle size, the higher the proportion of soluble compounds that can be extracted.

Therefore, grinding plays a critical role in coffee preparation. It’s also essential that all coffee particles are of uniform size to ensure even extraction. If they’re not, larger particles will extract fewer soluble compounds compared to smaller ones, resulting in uneven extraction. This will lead to a cup of coffee that contains both