A baker learns early in the baking process that it is difficult to make fine bread unless he or she gains a fair degree of insight into many of the chemical, physical, biological and mechanical aspects of the baking craft.  It is fitting that one of the seemingly most simple of organisms - a yeast cell - offers challenges that defy that assumed simplicity.  Yeast is a very complex organism, and its effects on baking are complex.  In this treatise we have tried to review as much of the literature available to us, and to distill it into a reasonable brief review of that literature. Since The Artisan has no research facilities capable of doing independent research aimed at better understanding what yeast does and why it does it,  we have relied on many sources.  However, that does not mean that any errors or misconstrued conclusions are the fault of those sources.  Errors of either commission or omission are ours, and ours alone.  We hope that visitors will inform us of any errors that we have made, and allow us the opportunity to correct said errors as appropriate.

Source materials for this Treatise have come from those authors and the works cited in the Bibliography found at the end of this document.


The baking process represents a highly complex set of physical, chemical, biochemical and biological activities. The microscopic yeast cell is responsible for the most important of these - Fermentation. Thus, yeast is the primary biological agent in dough formation, and discussions of yeast and its functions in the baking process are invariably intertwined with those pertaining to fermentation, and visa versa.

What are yeasts? Yeasts belong to the phylum Thalophytes. Members of this phylum form the most basic division of organisms in the plant kingdom, and are an undifferentiated group. Yeasts belong to this phylum along with other funghi, algae, and bacteria. Since funghi lack chlorophyll, they are dependent for food upon other organism's production of organic food matter. (Pyler) Thus, yeast must be fed to accomplish the task of leavening the dough. Yeast used in bread baking belongs to the genus Saccharomycetes and the species cerevisiae. More about this below.

Last Edited on: 12/25/2001 11:31:40 PM