This yeast ferments well in dark roast worts. Beers
fermented in the lower temperature range produce dry and crisp beers to
fruity beers with nice complexity in the upper range. Ester production is
enhanced with fermentation temperatures above 64 degrees F (18 C).
Flocculation is low to moderate with filtration typically required.
Alcohol tolerance Approx: 10%
Fermentation Temps: 62-72° F
Flocculation: Medium
Apparent Attenuation: 71-75%
This yeast produces some of the best Dry Stouts.
My guess is that this is Guiness's strain of yeast.
If you want to make a true Irish Stout this is the yeast
for you.