Two of the most common home coffee complaints have simple causes. Sour usually means you pulled too little flavor out of the coffee. Bitter usually means you pulled too much. Here is how to read your cup and fix it.
Sour, sharp, thin means under extracted
The water did not pull enough out. Fixes: grind a little finer, use slightly hotter water (aim for 200 F), or slow your pour down so the water spends more time with the grounds.
Bitter, harsh, dry means over extracted
The water pulled too much. Fixes: grind a little coarser, back the water temperature off slightly, or speed the brew up.
Change one thing at a time
The trap is changing three things at once and learning nothing. Move one variable, taste, repeat. Nail your coffee to water ratio first so it is out of the puzzle, then dial the grind. The step by step is in how to brew a better pour over.
And remember, stale beans taste flat no matter how well you brew. Fresh roasted coffee is the foundation. Get on the drop list for a new one each week.