One gram of compressed yeast contains more
than seven billion cells. Yeast reproduces by
budding. A bud (or gemma) grows on the mother cell
that detaches when it becomes an adult, giving life to a new cell.
Our yeast is a microscopic, single cell fungus,
with an eliptical shape, in the genus Saccharomyces cerevisiae,
present in nature and it is the primary ingredient in breadmaking
because it is responsible or the volume, structure,
aroma, and flavour of the bread.
During industrial production, yeast reproduces quickly and in large quantities, feeding on a sugary substrate made up of sugar beet molasses.
The process takes place in subsequent steps with increasing volumes, all of which are part of the industrial phase. Here, the fundamental step takes place, the one that determines the quality characteristics of the yeast that will be found in the end product that will reach the market.
Fermentation is aerobic (propogation): large quantities of air are blown into the culture broth, under the careful control of the most modern electronic instrumentation.
When it is used in dough, on the other hand, yeast grows very slowly and uses most of the nutritional sugar to product carbon dioxide and alcohol.
This is the leavening action that the breadmaker is looking for.