Yeast is one powerful ingredient. And one that gives you lots of options and room to play with. In bread, it has these main functions: to create gas bubbles in dough that allow it rise, to mature dough and give an airy structure, and to create wonderful and unique flavors.
Depending on variety, type, amount and fermentation time, the resulting flavor and texture possibilities abound.
How does yeast work?
Yeast promotes alcoholic fermentation, which breaks down sugars. Yeast is activated in the dough by moisture and carbohydrates, and is only active between 95 and 131oF.
Creamed, compressed and dry yeast
There are three main forms:
- Creamed yeast: yeast cells are suspended in liquid. Used in industrial, high-speed bakeries. 15-20% total solids.
- Compressed yeast: like creamed yeast, but most of the liquid is removed. Also known as cake yeast. 30-34% total solids.
- Dry yeast: it needs to be re-hydrated before use. The most common yeast to non-commercial bakers. 97% total solids.
How is it made?
Yeast production is a lengthy and multi-step process. It can be divided into four basic steps. In order, these steps are:
- Molasses and other raw material preparation.
- Culture or seed yeast preparation.
- Fermentation, harvesting and filtration.
- Packaging. This process takes approximately 5 days from start to finish.