yeast

Yeast isn't just something you find in bread! It's a tiny, single-celled fungus that helps dough rise and helps make beer, wine, and other fermented foods and drinks.

Think of it as a tiny worker feeding on sugar and releasing gas. That gas creates bubbles in dough and helps it expand. In drinks, the same process also helps create alcohol. While we mostly know it from baking, this living organism is found in nature too, including on plants and in the air. People have used it for thousands of years, long before they understood why it worked; they just knew that a bit of old dough could help new dough rise.

Yeast is a microscopic, single-celled fungus belonging to the kingdom Fungi. While often associated with baking, its influence extends far beyond the kitchen. It is a key part of many fermentation processes, changing sugars into carbon dioxide and alcohol. This is what makes bread rise and helps produce alcoholic drinks such as beer and wine.

There are many different types of yeast, with baker's yeast (Saccharomyces cerevisiae) being the most common for baking and brewing. It is sold in active dry, instant, and fresh forms, each with slightly different ways of being used. Active dry yeast is often mixed with warm water first, while instant yeast can usually be added directly to dry ingredients.

But yeast isn't just about food and drink. Scientists also study it because some of its basic cell processes are similar to those of more complex organisms, including humans. That makes it useful in research on genetics, medicine, and biotechnology.

Historically, people used yeast long before they understood what it was. Bread-making and brewing with yeast go back to ancient times, but it was not until the 19th century that Louis Pasteur showed that fermentation was caused by living organisms. So the next time you enjoy a slice of bread or sip a beer, remember the tiny fungus helping make it possible.