3.2. Fermentation time
The fermentation times for the dough to reach a total height of 10 cm
differed significantly between the different baker's yeasts (Table 2) from
40 min in the dough fermented with l'Hirondelle and Bruggeman to
100 min in the dough fermented with Malteserkors. This is in spite of
the fact that all doughs had the same initial yeast concentration. This indicates
that the baker's yeast named Malteserkors has lower fermentative
activity than e.g. l'Hirondelle and Bruggeman. A high fermentative
activity resulting in a short fermentation time is obviously an economic
benefit for the bakers if focus is solely on bread volume. Bell,Higgins, and
Attfield (2001) also found significant differences in the fermentative activity
of 39wild and domestic baker's yeasts. The fermentative activity of
S. cerevisiae have been found to be influenced by pH, temperature and
dissolved oxygen during an 8 h fed-batch cultivation, with the highest
fermentative activity at pH 6, 32 °C and 20% dissolved oxygen in the
phase of maturation of the baker's yeast (Angelov, Hristozova, &
Roshkova, 1997). Furthermore, the authors found that strains having
a high maltase activity were also having a higher dough leaving
ability. Hence, the different fermentation times observed for doughs
fermented with the seven commercial baker's yeasts (Table 1)might
be caused by differences within the cultivation method of the baker's
yeasts or by the mode of regulation of maltose utilization in the yeasts