What Goes Into Making Your Favourite Sandwich

Sandwiches can be breakfast, sandwiches can be snacks and even sometimes a treat when there’s delicious cheese dripping from it. But have you ever wondered what all goes into making that delicious cuboid? Apart from some healthy veggies or protein, most of it is processed food, like bread, mayo, butter and cheese. All these components of your sandwich are a result of simple scientific processes done with natural ingredients. Let’s take a look!

Fermentation In Bread

Bread is usually made with 3 basic ingredients, flour, water and yeast. Yeast is tiny single-cell microorganisms. They live off of simple sugars by breaking them down. Fermentation is the process of breaking down of glucose into carbon dioxide, ethanol (alcohol), flavour molecules and energy. So the yeast breaks down the sugar in flour thereby releasing carbon dioxide and alcohol that allows the bread to rise. This makes the bread soft and fluffy perfect for your early morning munching.

sandwich science

Emulsification In Mayo

What exactly is an emulsion? An emulsion is the mixing of oil and water using a binding agent called emulsifier. Oil does not mix with water, but when an emulsifier like egg yolks are used you get a thick emulsified solution. So mayo is an emulsion of oil and vinegar emulsified by egg yolks and some added flavourings.The hydrophobic end and hydrophilic end in the natural emulsifier in egg yolks form chemical bonds with both vinegar and oil keeping them together. Did you know that?

sandwich science

Breaking Emulsions In Butter

We just observed how an emulsion is made, know we’ll learn how it’s broken. Butter is a delicious byproduct of milk and is processed in many different ways. The most common being, churning. Milk is an emulsion of water and milk fats. When we churn the milk/cream we are trying to break this emulsion. When milk is churned vigorously, the fat globules collide with each other and burst its membrane. The fat released clumps together because of the cold temperature of the milk and form butter. The water that’s left behind is referred to as buttermilk.

sandwich science

Fermenting Dairy For Cheese

The next favourite ingredient in your beloved sandwich is cheese. Cheese as a spread, a slice or a cube, we love it in all forms. But how it’s produced is not known to many. It’s the same process of fermentation like in bread.

Which is, C6H12O6 (glucose) → 2 C2H5OH (ethanol) + 2 CO2 (carbon dioxide).

But here the ingredients used are not as few and common. So to ferment milk, lactic acid bacteria is added that naturally sours the milk by reacting with the lactose. This allows the milk and fat solids to coagulate and form solid curds. These curds are then further processed to make cheese.

sandwich science

Quite a process to get your sandwich ingredients from farm to plate, isn’t it? Know that you know the process of fermentation and emulsification. Can you observe if this process is used in any other foods that you eat regularly? Hint: Ice Creams.