Even though they generally perform as all other top fermenting yeast strains, Belgian Ale yeast get their own category due to their uniqueness and diversity that almost defies classification.
Belgian beers are characterized by significant yeast character — aromatic, fruity, phenolic, strong, dry. Characteristics of Belgian fermentation include increased phenol production.
Attenuation and flocculation is also much different than in normal brewers yeast. Some old Saison strains only attenuate 50 percent. They have to have very low initial gravities — in the mid-1020s. And the cells are usually smaller than other brewing yeast and are less-clustered. What does this low attenuation mean to brewers? Well, this is one of the main reasons that the strains are mixed, to increase the attenuation.