Yeast & Fermentation

Is Moretti beer top- or bottom-fermented? Bottom-fermented, like almost all major Italian lagers. The yeast works at low temperatures, around 8 to 12 degrees Celsius, and eventually settles to the bottom. The beer stays clean, fresh, and free of fruity side notes. Such a lager ferments for several days to about a week, then lagers cold for several more weeks.

Lager yeast, Saccharomyces pastorianus, is a hybrid of two yeast species. It ferments the wort slowly and thoroughly. After primary fermentation, the young beer goes into cold storage to mature further, allowing sulfur notes and residual fermentation aromas to fade away.

Luigi Moretti knew exactly why he made ice back in 1859. Without refrigeration, bottom-fermented beer simply doesn't work in an Italian summer. Over time, the ice factory grew into a modern operation, and today great beers mature in stainless steel tanks at controlled temperatures.

Craft brewers work differently. A pale ale like Point Break is fermented with top-fermenting yeast at room temperature, usually between 18 and 22 degrees Celsius. The yeast rises to the top, producing fruity aromas that complement the hops.

Bondai also brews a Berliner Weisse called Paura Paura. This style undergoes mixed fermentation, with yeast plus lactic acid bacteria, giving it a fresh, tart character. It proves that the craft scene between Udine, Sutrio, and Carnia explores many paths of fermentation. Set a tart beer next to a mild lager, and you'll instantly taste just how much yeast shapes a beer's character.