Proteins are important biopolymers that can contribute significantly to food structure. Controlling the manner in which they aggregate and form matrices within food systems is fundamental to sensory attributes and can have an impact on digestive properties. This work investigated the structuring behaviour whey protein isolate (WPI) over the entire acidic pH range from pH 1.0-6.8. WPI is a commercially available mixture of several proteins. β-lactoglobulin is most abundant and tends to dominate the functionality. Some important aspects are the clarity of protein solutions in beverages, the temperature of denaturation, the aggregation characteristics and consequently the gel forming properties. pH is a key factor which affects all of these properties and there remains aspects worthy of further investigation. In this presentation, the role of pH in denaturation, aggregation and structuring will be discussed in detail along with the trends observed. Some previously unknown aspects surrounding the behaviour of whey proteins at specific pH points and their applicability to commercial products will be highlighted