Uses of Yeast: Definition, History, Types and Significance in Everyday Life

Humans have been using yeast for centuries to ferment beverages and bake breads. It is one of the oldest domesticated microorganisms, known to be used by many ancient civilizations. Egyptians and Chinese started using yeast for making baking breads and fermenting beverages around 5000 years ago. Even today yeast is an industrial microorganism used for making many different food products. In this article we will learn about these interesting uses of yeast along with its history and role in our environment.

Table of Contents

• What is Yeast
• History of Yeast
• How Yeast Works
• What are the Uses of Yeast
• Types of Commonly Used Yeasts

What is Yeast

Yeast is a single cell microorganism called eukaryotic that is a part of the Fungi family. There are around 1500 species of yeast found in nature. They are present in soil, air, plants and even inside our bodies. It feeds on sugar and creates fermentation that is used for many different purposes. Yeasts are natural decomposers that break down dead matter and return the nutrients back to soil. Further, we will learn in detail about the environmental and commercial uses of yeast along with its brief history and functioning.

History of Yeast 

Yeast got its name from the old English word ‘gyst’ which means bubble or rise. It originated hundreds of millions of years ago. Even before many languages were created, the yeast-raised breads were being baked in ancient Egyptian civilizations around 5000 years ago. The baking and fermentation uses of yeast became popular. This knowledge from ancient Egyptians and Babylonians passed on to Greece and Jewish which then spread to the whole world. This is how yeast became one of the oldest domesticated microorganisms for preparing food and drinks around the world.

How Yeast Works

Yeast works through a biological process called fermentation that breaks sugar and carbohydrates to produce energy in a warm and moist environment. Fermentation is a metabolic process in which yeast breaks sugar into gases and organic acids. The products released from this reaction are carbon dioxide and ethyl alcohol. When yeast is added to the dough, it consumes the sugar in the flour, releasing carbon dioxide gas that gets trapped inside the dough and inflates it. 

What are the Uses of Yeast

Different species of yeast are used for different purposes:

Baking: Yeast is one of the most important agents used in baking. When we add yeast to flour, it becomes warm in the oven and expands to make the dough rise. This process makes the bread spongy and soft.

Beverages: Yeast consumes sugar in grains and fruits that produces ethanol and carbon dioxide that is used in making wines, beer and spirits.

Fermented Foods: Some batters and traditional foods are fermented to enhance the taste and flavour of dishes. Fermented foods are easy to digest as well.

Medicinal Use: Yeasts are also used for medical purposes for making vaccines, enzymes and natural proteins. 

Environmental Use: Yeasts support natural soil enrichment by decomposing organic dead matter. They also absorb nitrogen from the environment for making their food and is a sustainable alternative to fossil fuels.

Supplements: Many health care products and supplements have yeast as it is rich in vitamins, proteins and minerals.

Biofuel Production: Yeast ferments sugar from plants to produce bioethnol which is a natural fuel for transportation and energy production.

Preserving Food: Fermentation done by yeast lowers the pH of food due to the presence of alcohol and prevents it from getting spoiled by harmful bacteria.

Types of Commonly Used Yeasts

Based on the types of uses of yeast, it is classified into the following different types:

Baker’s Yeast: Used for baking bread, pizzas, cakes and other baked goods, this type of yeast is the oldest microorganism being used over thousands of years. The gases released in fermentation help in raising the dough, making cakes and other baked goods soft as well as spongy. During baking the ethanol produced during evaporation gets evaporated due to heat of the oven. 

Nutritional Yeast: This type of yeast is used in nutritional foods and supplements made for health benefits. As yeast is rich in vitamins, minerals and proteins they are used for enhancing the nutritional value of food.

Brewer’s Yeast: This yeast is used for fermentation of fruits, vegetables and grains to produce alcoholic beverages as the fermentation results in producing ethanol and carbon dioxide.