Mixture experiments are a special class of response surface experiments in which the product under investigation is made up of several components or ingredients. In the simplest mixture experiment, the response (the quality or performance of the product based on some criterion) depends on the relative proportions of the components. In contrast, in a factorial design, the response varies depending on the amount of each factor.

Minitab can create three designs (simplex lattice, simplex centroid, and extreme vertices) and analyze data from these types of experiments:

·    mixture experiments

·    mixture-amounts (MA) experiments

·    mixture-process variable (MPV) experiments

Researchers in a food laboratory are trying to improve a recipe for cheese fondue. They would like to study the effects of the mixture blend as well as the temperature at which the fondue is served on the flavor (Flavor).

The mixture is comprised of three ingredients: two types of Swiss cheese (Emmenthaler and Gruyere) and white wine.