Fermented Foods and Yeast
In almost every country around the world, people consume fermented foods daily. Many individuals eat these foods without even realising they're fermented, and rarely think about fermentation in their daily lives. Despite most people having little knowledge about the fermentation process itself, they maintain a surprisingly familiar relationship with fermented foods. Some form of fermented food exists in virtually every culture across the globe. While yeast is an essential element in alcohol production, its applications extend far beyond the brewing process. In the fermented foods mentioned earlier, yeast plays a tremendously important role during their creation. It's also used in baking, and due to its rich nutritional profile—abundant in vitamin B, protein, and minerals—yeast is sometimes used as a dietary supplement for health benefits.
The Role of Yeast in Brewing Processes
Yeast is a microorganism that consumes sugars, releases carbon dioxide, and produces alcohol. Though too small for the naked eye to see, these microscopic organisms are responsible for creating alcoholic beverages. There exists a wide variety of yeasts, each with different properties and characteristics.
The specific yeast strain used plays a decisive role in determining the final flavour of the finished alcoholic beverage. The quality of the alcohol can largely be determined by how quickly and abundantly alcohol is produced during fermentation. Rapid alcohol production helps inhibit the growth of lactic acid bacteria and acetic acid bacteria, preventing unwanted sour flavours in the final product.
Additionally, the yeast itself must have strong resistance to alcohol to maximise the potential alcohol content in the finished beverage. For this reason, different types of alcoholic beverages require different yeast strains specifically selected for their particular production needs.
The traditional approach to Korean alcohol production doesn't rely on cultivating a single specific yeast strain. Instead, alcohol is generated by diverse wild yeasts present within nuruk, a traditional Korean fermentation starter. Unlike koji (the Japanese fermentation starter), nuruk employs various yeasts rather than a single strain to produce alcoholic beverages.
This method results in less consistency in the final product but allows for a wider range of flavours and aromas. Similar to how a wine's taste is determined by the quality of grapes used that year, traditional Korean alcoholic beverages derive their distinctive flavours from the quality of the nuruk used in fermentation.
For those interested in learning more about this unique fermentation starter, the article "Exploring Nuruk: The Foundation of Korean Brewing Traditions" provides an accessible introduction to understanding its significance in Korean brewing traditions.
Understanding Enzymes
If yeast is the microorganism that produces alcohol, then what exactly are enzymes? Some people occasionally confuse the meanings of yeast and enzymes, and some even believe they are the same thing. However, yeast and enzymes are entirely different.
Enzymes are not microorganisms but rather catalysts composed of proteins formed by polymerized amino acids that accelerate biological reactions. They can break down certain substances or combine materials to create new ones. These enzymes don't exist in just one form—there are many different types.
For example, enzymes that break down proteins can only decompose proteins, while enzymes that break down starch can only decompose starch. A single enzyme cannot break down both starch and protein simultaneously. Enzymes with this substrate specificity exist abundantly in animals, plants, and microorganisms, with an incredibly diverse range of varieties.
The Role of Enzymes in Alcohol Production
In the alcohol production process, enzymes that can break down grains into smaller components are essential. Through enzymatic action, grains are repeatedly broken down until they become substances too small for further decomposition. This process requires enzymes capable of producing glucose—this glucose is then consumed by yeast, which releases carbon dioxide and produces alcohol.
This is why Western brewing traditions utilise malted grains, while Eastern brewing techniques have developed methods using malt extracts and molds. In Korea specifically, nuruk has been developed for alcohol production. The enzymes present in nuruk break down grains into sugars, enabling alcoholic fermentation that converts those sugars into alcohol. For more detailed information about the alcoholic fermentation process, you can find a comprehensive explanation in another article titled "The Science of Alcohol Fermentation: Understanding Single and Double Processes"
Beyond Brewing : The Broader Significance of Yeast and Enzymes
Yeast and enzymes exist far beyond their applications in alcohol production. Their functions and structures related to brewing represent just a small fraction of their importance, as they're involved in virtually all aspects of human life. While there is still much to study and understand about these fascinating biological elements, I've attempted to provide a brief explanation of the roles that yeast and enzymes play in the production of alcoholic beverages.
These microscopic organisms and molecular catalysts impact everything from the food we eat and the medicines we take to the fundamental metabolic processes that keep our bodies functioning. The brewing sciences have simply harnessed natural biological mechanisms that have evolved over billions of years, adapting them for cultural and culinary purposes.
The relationship between humans and these invisible yet powerful biological tools continues to evolve as our scientific understanding deepens, opening new possibilities in biotechnology, medicine, and sustainable production methods that extend well beyond the creation of alcoholic beverages.
