Answer: Crowd-storming
Explanation:
Crowd-storming is defined as the process that links crowd-sourcing and brainstorming together.External sources are the base of ideas or invention which are reached to gain opinions and then a particular decision or solution for any particular case is extracted through group activity.
According to the question, crowd-storming is being depicted through the scenario .As the coffee shop is using external source(fans) to obtain ideas about iced coffee . Creators in form of group will then make decision about the winner of the coffee contest through tasting their recipes