While homebrewing high-gravity, high-alcohol beer always presents challenges, making imperial saison at home may be somewhat easier than brewing other high-gravity styles. Because so much of the character of saison is driven by yeast, it’s possible to “imperialize” a saison with only minor adjustments to the basic formulation.
Yeast
Forget everything you think you know when working with saison yeast. Some strains are notoriously finicky, while others are easier to use. White Labs 565 and Wyeast 3724 (reportedly descended from Brasserie Dupont’s strains) are famous for stopping partway through fermentation and may require temperatures as high as 95°F (35°C) to achieve full attenuation. White Labs 568 and Wyeast 3711 may be better choices for homebrewers who have neither the time nor the patience to attend to the demands of a high-maintenance yeast strain. Brewers who prefer dry yeast may consider Safbrew T-58 from Fermentis and Belle Saison from Lallemand.
A signature hallmark of saison is its dry finish. The BJCP and GABF style guides list terminal gravity ranges for saison at 1.002–1.012 and 1.004–1.016, respectively. Imperial saison should also finish dry, but the higher alcohol and higher hops levels demand more body and slightly more sweetness for balance.