There has been considerable research in recent years on the texture and sensory properties of cultured dairy products. This article gives an overview of the formation of structure in cultured products (primarily in relation to yoghurt, cottage cheese and sour cream) and suggests approaches to controlling their textural properties. Two important themes concerning this topic are first that the casein micelles are the building blocks of acid gels so casein chemistry and casein interactions are important, and second that an understanding of the gelation process is the key to controlling the physical properties of cultured products. The impact of several processing steps on the structure of cultured dairy products is discussed. Textural properties and the possible causes of defects such as whey separation and lumpiness are also discussed.