Buttermilk is the tangy liquid left in a butter churner after the cream has hardened into butter. Buttermilk contains tiny specks of creamy butter, giving it a sweet, slightly sour taste.
When milk sits in a butter churner, it undergoes a process called fermentation. During fermentation, bacteria convert a carbohydrate into an alcohol or acid. In this case, the lactose in the milk becomes lactic acid. Other foods such as beer, wine, cheese, and yogurt are also made by fermentation.
In the late 1800’s, Louis Pasteur discovered that heating fermented liquids such as wine or beer kills the bacteria that cause them to spoil. Moreover, this method, known as pasteurization, was also used to sanitize milk, which at the time often carried tuberculosis. Heating the liquid denatures the enzymes in the bacteria, changing their shape and preventing them from functioning properly. Without these enzymes, the bacteria cells cannot undergo normal processes and therefore die. Additionally, heat causes the liquid in the bacteria to expand, eventually bursting the cells.
Instead of directly heating the liquid, factories use specialized machines called pasteurizers to sanitize the milk without altering its taste or quality. Raw milk enters the machine and passes through tubes heated by steal plates surrounded by hot steam or water. Temperature sensors ensure that the milk warms completely. The milk must reach 161° F – if not, it circulates through the pasteurizer again. Afterwards, the pasteurizer chills the milk down to 39° F with coolant, a cold liquid or gas. This process kills 99.999% of microorganisms without sacrificing nutritional value. Once the milk is cooled, it is packaged, labeled as pasteurized, and sold.
Nowadays, cultured buttermilk is made by adding live lactic acid bacteria to pasteurized milk. The mixture ferments for 12 to 14 hours at a low temperature to prevent the bacteria from dying.
Oftentimes, recipes call for buttermilk in the place of regular milk. Since buttermilk is slightly acidic, it reacts with baking soda to produce CO2 bubbles, causing baked goods to rise. This reaction also yields browning. Furthermore, buttermilk adds extra flavor to fluffy pancakes, silky panna cotta, and delicious scones.
To make buttermilk at home, just combine 1 scant cup of milk with 1 tablespoon lemon juice or white vinegar. Let stand for 5 to 10 minutes. As it ferments, the milk will thicken and small lumps will form. Just add a few extra ingredients to turn this tangy cream into delightful buttermilk scones!
The scones start with a basic dough, rolled out, and cut into triangles.
Cold butter creates light, flaky layers.
A wonderful breakfast or an afternoon treat with tea.
Pair with tart strawberry jam. No extra butter necessary!
3 ½ cups flour
1/3 cup sugar
1 tsp salt
2 ½ tsp baking powder
½ tsp baking soda
¾ cup butter, cold and cubed
1 cup buttermilk
Preheat oven to 400° F.
Combine the dry ingredients. Using a fork, cut in the butter until pea sized lumps form. Add the buttermilk and mix until a ball forms.
Divide the dough into two. On a floured surface, form half of dough into a circle about ½ inch thick. Cut into 6 triangles. Transfer to a greased baking sheet and bake for 12 to 15 minutes or until edges are golden.
Makes 12 scones.