Page 44 - #54 English

Cover Story

process avoids any re-infection and the end result is a product your steam wand to froth the milk, millions of tiny air bubbles
that lasts up to six months without refrigeration or preservatives. are injected into the milk. Milk proteins are destabilized by the
heat (their structure, which resembles a ball of wool, begins to
Sterilized milk goes through a more severe form of heat unravel) and the protein molecules start to wrap around the air
treatment, which destroys nearly all the bacteria in it. First, the bubbles. This creates a protective coating that keeps the bubbles
milk is pre-heated to around 50 degrees Celsius, then homog- from bursting. However, different kind of milk require different
enized, after which it is poured into glass bottles or can which are amounts of steaming time since each type of milk have differ-
closed with an airtight seal. There is no legally defined process ent molecular compositions. Several components of milk play
for sterilizing milk but, commonly, filled bottles are carried on an important role in creating stable foams and delicious tasting
a conveyor belt through a steam chamber where they are heated drinks, and that is proteins, carbohydrates, and fat. For creating
to a temperature of between 110-130ºC for approximately 10-30 stable milk foams of desirable texture and stability, milk fat and
minutes. Then they are cooled using a cold water tank, sprays or, milk proteins are of crucial importance. Milk proteins stabilize
in some cases, atmospheric air and then crated. The sterilization the air bubbles in milk foams. Milk fat destabilizes foams, but
process results in a change of taste and color and also slightly is desired for flavor. Heating up these fat molecules not only
reduces the nutritional value of the milk, particularly the B group affects foam texture; when heated or steamed, the fatty acids
vitamins and vitamin C. also participate in chemical reactions, such as oxidation reac-
tions, that can give rise to an undesirable flavor. The steaming
Evaporated milk processing is made by heating milk temperatures for each type of milk are thus differed due to their
until about 60 percent of its water content has evaporated. It is distinct properties.
then homogenized, packaged, and sterilized. The result is a dense,
creamy, ultra-concentrated milk that can be canned and stored Choosing the Right Milk
for several months. The high heat used in processing also adds a Whole milk produces in a soft and creamier foam that
slightly caramelized flavor and darker color than regular milk. flows easily on the surface of your coffee. While skim milk re-
sults in more foam, larger air bubbles, and the consistency is less
Condensed milk is sometimes used in many Asian coffee supple because of its higher protein content than whole milk.
shops with menus like Kopi or Thai-style iced coffee. It is made The real difference between the two foams was their smoothness
by condensing milk to one-third of its original volume and add in and taste. The fat content adds a wonderful texture to the drink
sugar. It is very thick and sweet and is available in cans. and also changes the way flavour is released. Coffee made with
skimmed milk has an immediate and intense flavor that does not
Steaming Milk linger while coffee made with whole milk, the flavors will be less
Well-steamed milk combined with great-brewed espres- intense but will last longer. This sums up that all forms of milk
so is a wonderful sensory experience. Great milk foam is like can produce foam regardless of their fat content, but what really
liquid marshmallow: soft, mouse-like and enjoyable to drink. Have whip them up is the protein. The different protein content of dif-
you ever wonder how does milk froth work? And how it form that ferent milk consequently affects each milk’s ability to maintain
stable silky texture? Let’s explore a bit deeper. that frothy foam. Protein content can vary slightly depending on
the time of year and how the milk is processed. Creating stable
Steaming milk is the process of injecting hot water milk foams is an intricate interplay between balancing the desir-
vapor into cold milk until it reaches the ideal temperature and able foaming properties of milk proteins with the destabilizing
amount of froth for your perfect coffee beverage. When you use milk fat.
44