Chapter 6 – The Syneresis of Rennet-Coagulated Curd

Gels formed from milk by renneting or acidification under quiescent conditions may subsequently show syneresis, that is, expel liquid (whey), because the gel (curd) contracts. Under quiescent conditions, a rennet-induced milk gel may lose two-thirds of its volume, and up to 90%, or even more, if external pressure is applied. Often, syneresis is undesired, for example, during storage of products like yogurt, sour cream, cream cheese, or quark; hence, it is useful to know under what conditions syneresis can be (largely) prevented. In making cheese from renneted or acidified milk, syneresis is an essential step. Consequently, it is useful to understand and quantitatively describe syneresis as a function of milk properties and process conditions, particularly when new methods or process steps are introduced in cheesemaking.