Based on what I learned recently from my Introduction to Philosophy class, “Existence = Attributes.”

From the natural perspective, bitterness is a quality or an attribute. In line with this, taste is a matter of preference. Allegorically, it is plausible that you may be referring to the bitterness in life based on experiences. (i.e. life could be compared to the bitterness found in coffee)

I am sure that you would know this, I am certain that you are a coffee drinker as well.

P.S. Fingers crossed that this is the answer that you are looking for. :)