Yes it is supposed to taste very bitter.
You can tell if tahini is bad by checking for any changes in color, smell, or taste. If it has a rancid or sour smell, a strange color, or a bitter taste, it is likely spoiled and should not be consumed.
Tahini has a very interesting flavor combination that is creamy, a bit nutty and slightly bitter. You can get a general idea of the flavor by eating 1 teaspoon of sesame seeds.
Acids taste bitter.
A base typically has a bitter taste.
A good miso alternative for those seeking a different flavor profile in their dishes is tahini. Tahini is a paste made from sesame seeds and has a nutty and creamy taste that can add a unique flavor to dishes in place of miso.
Campari has a bitter taste.
It is incredibly bitter, definitely an acquired taste
Tahini can last up to a year if stored properly in a cool, dark place. It can go bad if it develops an off smell or taste, or if mold appears.
Bases taste bitter. Acids taste sour.
Alkaloids usually have a bitter taste
Bitter-melon.
Some minerals can have taste characteristics such as salty or bitter taste.