What is a key difference between lager yeast and ale yeast?

The key difference that makes the chosen answer accurate lies in the characteristics of lager yeast compared to ale yeast, particularly regarding their fermentation abilities. Lager yeast, which belongs to the Saccharomyces pastorianus species, can ferment a broader range of sugars than ale yeast. This includes not just glucose but also melibiose, a disaccharide formed from galactose and glucose. This ability contributes to a more complete fermentation process, which often results in higher attenuation levels, or the conversion of sugars into alcohol.

Lager yeast generally ferments at cooler temperatures (typically between 45°F to 55°F or 7°C to 13°C), which allows it to produce its characteristic clean and crisp profile without many of the fruity esters and phenols that are typical of ale yeast fermentation. On the other hand, ale yeast, such as Saccharomyces cerevisiae, thrives at warmer fermentation temperatures (60°F to 75°F or 15°C to 24°C), which leads to the production of a more complex array of esters and phenols that can enhance flavor and aroma in the final beer.

Hence, while lager yeast's capability to ferment melibiose is important for its attenuation and fermentation characteristics, it highlights part