faster starter processes, requiring fewer refreshments, have been devised, sometimes using commercial sourdough starters as inoculants. these starters generally fall into two types. one is made from traditionally maintained and stable starter doughs, often dried, in which the ratios of microorganisms are uncertain. another is made from microorganisms carefully isolated from petri dishes, grown into large, homogeneous populations in fermentors, and processed into combined baker's products with numerically defined ratios and known quantities of microorganisms well suited to particular bread styles.