This is a question we used to get ALOT in our cafe'. While I wish it were rocket science, it's not.
There are a number of variables that go into making great coffee, (another blog), but in the end one of the most abused, that is the one ignored ALL THE TIME is the most simple.
You need to use enough ground coffee when brewing coffee to produce great coffee.
This can be hard at home because the dripper's basket 'throw' (the amount of coffee it can hold), may not be large enough to hold the needed coffee with sufficient room for the water so it does not overflow. But in the coffeehouse business our brewers can handle it AND MORE so there is no excuse.
Restated, most places serving marginal coffee simply DON'T use enough ground coffee, (regardless of quality), to brew the coffee you are paying for. Why? Well, it normally comes down to a couple of possibilities:
1 Choice. This the worst case. By measuring less than what is needed the shop is choosing to raise their profits by serving 'thin' coffee.
2 Ignorance. This means that they are not trying to make bad coffee or increase their profits , but are lost with regard to what the caclulations/recipes are for great coffee. Strange, in a coffeehouse, to not know this, but ... well ...
I would guess that this is the most common.
3 Mistake. This is the least likely. They have the knowledge but day in and day out are somehow not applying it or are miscalculating.
In all of the above, what happens is that even a wonderfully roasted varietal will not have the body or the mouth 'feel' that it should.
If your coffee is thin, you can actually see through it when it pours.....look at the coffee when its pouring....if its light caramel in color, its likely to be thin. Even a lightly roasted coffee should pour 'looking' thick.
Now, if your coffee is rich looking when it pours, we have a whole 'nutha' issue. Which is much more technical actually and will be in another post......john