Hi, I'm a regular coffee drinker. I used to take "instant coffee (black, without
sugar or milk). " Recently, I've started taking "filter coffee (black, without sugar or milk). I simply pour boiling water in "filter coffee" and stir it intermittently for 3-4 minutes until insoluble granule settles down (I don't use funnel or gauge to separate insoluble part), and I drink it and throw away the insoluble matter. I want to know if it's healthy way to drink filter coffee?