We have all eaten banana cream pies; sundaes topped with a dollop of whipped cream; waffles covered in mountains of swirly whipped cream; or slices of cream-covered Tres Leches cake. However, most of us have only ever made whipped cream by spraying it from a can. What exactly happens when cream is made into whipped cream? And how is butter made from this same substance? In Food Science class, Just Bakery students set out to find the answer.
First, students learned the theory behind how milk fat behaves. Milk is full of small particles of fat called globules, made up of a thick membrane on the outside and liquid fat on the inside. In non-homogenized milk, those globules will rise to the top and form a layer of cream nearly ten times as fatty as milk.
When cream is whipped, the motion of the whisk tears tiny holes in the globule’s membrane, exposing patches of the sticky fat underneath. The globules begin sticking to each other, forming a network of fat particles and pockets of air. That is called whipped cream. However, if you continue to beat or churn the whipped cream, the globule membranes will become so damaged that the liquid fat on the inside leaks out and pools together in yellow clumps. Those clumps are kneaded together into butter.
After studying the science of milk fat, Just Bakery students conducted an experiment to witness the process of transforming cream into butter. First, they split into two teams: Therese and Gustavo versus Adam and Jesus. Each team was equipped with a bowl, a whisk, and a cup of heavy cream. They raced to see which team could whip the cream into whipped cream the fastest. Whisking by hand is very hard work, and as the students’ wrists became tired, they handed off their whisks to other members of their teams. Therese and Gustavo were winning; as the cream thickened up and became fluffy, they beat it even faster, until it formed soft peaks in the bowl. It had reached the perfect stage for spreading on top of a banana cream pie.
The next step was even more challenging: beating that whipped cream until it became butter. Once again, the two teams picked up their whisks and attacked the beautiful fluffy white cream. They watched as it slowly lost it fluffiness and assumed a clotted, gritty appearance. After 10-15 minutes of beating, the cream had turned yellow and granular, and had released a thin whitish liquid called buttermilk. The students drained the buttermilk away, sprinkled on some salt, and kneaded the butter grains with their hands, forming a solid mass of soft yellow butter.
The butter was ready to eat. The students spread it on slices of Just Bakery bread, and sampled the fruits of their experiment.
…by Diana G…