Answer:
Focus group
Explanation:
The focus group refers to the people who are involved in a group to discuss about the topic that is related to the research of the market or the analysis of something or discussing for the new product.
It is an open discussion so that everyone who is in a group put their ideas and analyzed it what reactions would be received from an entire population
Since in the question, the taste and preferences changes constantly and the problem is that you are not aware of the flavours what actually people want so it should be discussed in a group so that proper analysis could be made by considering everyone perceptions
Therefore this research represent the focus group