This course is aimed at raising an awareness of the whole chain of production from farm to cup. Coffee consumers have become more aware of coffee-farming practices, but milk production has remained, for many of us, a subject about which we know little. The popularity of latte art and the widespread love of milk-based coffee tells us at Barista Hustle — and as an industry — that we need to develop a respectful understanding of milk production.
Chapter 1 lays the framework for an holistic understanding of all the ingredients a barista works with. We explore the practice of dairy farming and dairy processing. We interview a dairy farmer to get an insider’s view of cows’ diets and a better understanding of what improves cows’ nutrition. We learn what it takes to produce milk that has the desired qualities of texture and flavour.
In Chapter 2 we go deep into the chemistry of milk foam, with assistance from Steven Abbott, a world expert of surfactant science. In particular, we examine the role of certain proteins in helping to hold bubbles together.
In Chapter 3 we look at how milk fats interact with milk foams. We explore how the milk fat globule reacts to being heated. And we explore how certain antifoams can interrupt the milk foaming process. Then we move on the milk sugars. We examine how lactose is made up and how lactose free milk is made too.
In Chapter 4, we look at some important phenomena that explain why some milk foams are ideal for latte art, and some are not usable. We explore lipolysis and how free fatty acids cause bubble rupture. We also look into ostwald ripening and how smaller bubbles are more immune to its effects. By the end of this chapter, readers should have developed a very thorough understanding of all the steps in milk processing, and the physics and chemistry of what makes milk such a great product for pairing with specialty coffee.