COFFEE GRIND - coarse, medium, or fine?

[AmberJayBird]

It is recommended to use either coarse, medium, or fine grind coffee depending on the method (how long the water will be in contact with the coffee, presumably affecting strength). Drip coffee is supposed to be brewed with medium grind. Why can't I just use a fine grind and use less coffee grounds? Does this negatively affect the flavor? Scientifically speaking, it seems that it's just a matter of surface area so if I use higher surface area (fine grind) and less grounds then I can achieve the same strength of coffee and use less of it (save money!!). Does anyone know if this is supposed to negatively affect the flavor?

[Androcles]

I suspect you would be right, AJB, if the particles remained in the same relative position to each other, but I think if you use fine grind with a drip method, it tends to remove the air, the particles get closer together and stick together with surface tension, so the water cannot get through - it forms a sort of mud cap. The result is a wait for hours and weak coffe as the water finds the route through which will probably be round the edges.

That's one theory, anyhow!