The way that Joan found that required no refrigeration was the use of powdered milkshakes.
What method did Joan discover?
Joan wanted to introduced a powdered milkshake which apparently tasted much like ice cream.
Because it was made of powder, it did not have to be refrigerated to maintain its structure which made it a cost effective alternative to ice cream.
Find out more on cost effective methods at https://brainly.com/question/199821.
