Optimization by Ad Libitum Mixing and the Just-About-Right Scale
This exercise demonstrates the use of two methods for optimization of an ingredient level (sugar content) that influences sweetness and product acceptability in a beverage system. Two methods are used, the just-about-right scale (JAR) and a method of adjusting the sample to taste preference. The adjustment method is prone to a context effect in which the taster is likely to undershoot the true optimum when either ascending (adding) or descending (diluting) the sweetness level. The JAR scale method is prone to a centering bias, in which the middle concentration in a series is more likely to be called “just right” or optimal. A method for graphically interpolating the true JAR point from two overlapping concentration series is illustrated.