The different coffee varieties are not equal. There are very bitter and acidic coffees that cause heartburn and leave an unpleasant aftertaste in the mouth.
What I did not know, is that you can neutralize this bitterness and acidity, that are very unpleasant!
Add ¼ teaspoon of ... baking soda to the coffee beans before preparing a carafe.
Baking soda is alkaline and neutralizes the acidity. The small amount added to the coffee will make all the difference, especially if you bought coffee beans that have bitter taste.
It is an excellent habit to take because the taste of bicarbonate is not detectable in coffee, but its action helps to avoid the inconvenience of a coffee too acid on your stomach!