On my recent visit to the local library (yes I do get geeky at times) I came across a pamphlet oddly titled “how churn can be prevented or reduced”; at the first look at I thought it must have something to do with the use of the term churn in financial world, however on reading I realized it was about our good old butter churning process! Churning milk or cream gives us our ubiquitous butter, then why would anybody want to prevent milk churn, you might ask (I wondered so too). Well, it seems though churning is a highly desirable process in butter making, involuntary churning of milk during transport causes severe loss of milk fat along with many other flavor and texture changes in the milk; hence churn reduction or prevention has been a hot topic of research in dairy industry!

Churning, as we all know, is the process of vigorously shaking up the milk to separate fat from the milk. Milk is actually oil in water emulsion of dairy fat and dairy liquids; what churning does is breaks this emulsion (partially or completely) making part of the dairy fat to precipitate out, which in turn changes the flavor, texture, and composition of the milk.

When raw or unhomogensized milk is being transported over long distances, the exaggerated movements of transportation lead to spontaneous churn formation in milk. Apparently this occurs not just due to shaking up of milk; incorporation of oxygen and favorable temperatures are also required for the milk to get churned. Based on this there are 3 main techniques that the dairy industry uses to prevent or reduce churn:

•  Avoiding head space: Since agitation is essential for churn to form filling up the milk cans or containers completely, leaving no head space during the transportation will obviously reduce churn formation.

• Maintaining low temperatures: When the fat globules in the milk are slightly solidified, churning is not possible. Hence, some companies use specialized cooler equipped transport systems to maintain the temperature of the milk container below 10^oC and thus prevent churn.

•  Addition of additives: Certain additives like sodium metaphosphate have been used on experimental basis to prevent the milk from churning. Though this technique has shown to have some success, I have not yet come across any data to prove that it is being used commercially in the milk that we consume, hence cannot comment on this.

So these are some of the ways used by dairy industries try to prevent or reduce churn formation in unhomogenized or raw milk. There might be many more techniques that I am not aware of. If you know of any please feel free to share it with me. Special thanks to NIDDI (dairy institute), for allowing me to share all this information with you guys.

Image credits: google.con