Many bakers are unconditionally loyal to a particular format or brand. In professional circles, consistency is very important so yeast is chosen carefully. At home, we need a yeast which suits most of our baking needs. Your grandmother probably used fresh yeast.
Purists adore it.
Doughs made with it are supple and bouncy and the yeast fragrance is subtle. Fresh yeast, usually the choice of professional bakeries, is best for doughs which will not undergo excessive handling. The strains used to make fresh yeast are different from those used to make dry yeast. Fresh yeast, of course, has no lag phase. Fresh yeast does have its drawbacks.