Yeast is a type of single-celled fungus that is found in many different environments, including soil, plant surfaces, and aquatic habitats. Yeast is also commonly used in food and beverage production, such as in bread baking and beer brewing.
The specific origin of yeast is not entirely clear, but it is believed that yeast has been present on Earth for millions of years. Yeast is known to have evolved alongside other microorganisms, and it has played an important role in many different ecological processes.
For commercial purposes, yeast is typically produced in controlled laboratory environments, where it can be grown and harvested under specific conditions to ensure consistency and quality. Different strains of yeast are used for different purposes, depending on their unique characteristics and properties.