Yeast
Yeast, a microscopic fungus, plays a vital role in various aspects of biology and industry. It's crucial in baking, brewing, and fermentation processes, converting sugars into alcohol and carbon dioxide. In biology, yeast serves as a model organism for genetic research. Its versatility and significance make yeast a fundamental microorganism with diverse applications in both scientific and culinary fields.
Yeast is a single-celled fungus and one of the most widely used ingredients across general provisions and staple foods. Its largest application is baking, where it acts as a leavening agent: the yeast feeds on the sugar in the dough and produces carbon dioxide gas, which causes the dough to expand and rise. The same organism underpins fermented foods and beverages such as beer, wine and cheese, where it converts sugars into alcohol and other byproducts through fermentation.
The global yeast market was valued at around USD 4.5 billion in 2020 and is projected to reach USD 6.3 billion by 2027, at a CAGR of 4.5% from 2021 to 2027. Beyond food and beverage, yeast is also used in animal feed, biofuels and pharmaceuticals, which adds further growth opportunities. Asia-Pacific is expected to grow at the highest CAGR, driven by rising demand for bakery products and alcoholic beverages, particularly in China and India. Major players include Angel Yeast Co. Ltd., Lesaffre Group, Lallemand Inc., Associated British Foods plc, Kerry Group and Koninklijke DSM N.V.
Commercial yeast production runs as a controlled fermentation using a specific yeast strain. A nutrient-rich culture medium containing sugars, amino acids, vitamins and minerals is prepared and sterilised to prevent contamination. A pure culture of the selected strain is then inoculated into the sterile medium and allowed to grow, before transfer to a larger fermentation vessel where the yeast multiplies, consuming sugars and producing alcohol and carbon dioxide. Temperature, pH and oxygen level are carefully controlled throughout to optimise growth and fermentation.
Downstream, the yeast cells are harvested from the culture medium by centrifuge or filtration system, washed and dried to reduce moisture content using a spray dryer or another drying method, and finally packaged into bags, drums or boxes for distribution. For a plant owner, the design decisions concentrate around sterility of the medium, instrumentation and control of the fermenter, and the harvesting and drying train that determines final product quality.