fermenting the mash

In the master brewer's day this is the last phase of truly active work, here the beer becomes a proper product.

The master brewer adds yeast to the beer mash in the fermenter that until now has been made up of water, sugars, proteins, hop substances and mineral salts.

At a temperature of 22° C, thanks to the addition of oxygen and yeast, the sweet beer mash begins the fermentation that is simply the transformation of maltose into alcohol and carbon dioxide. During this process, which can last from three to seven days, both degrees Plato and pH are periodically checked.

At the end of the fermentation period the temperature is considerably reduced to precipitate the yeasts in order to facilitate the decantation of the beer.

The fermentation phase complete, the beer that only now can truly be referred to as such, is passed to the aging vat.

The yeast which remains from the emptying of the fermenting vat is recovered and reused.

Top fermentation
Fermentation with Saccharomyces cerevisiae yeast at 18-22° C, the only available until 180 years ago, it gives the beer a soft, rounded taste.

Bottom fermentation
Fermentation with Saccharomyces carlsbergensis yeast at 4-10° C, it yields a dryer taste.
Noted both for economic reasons and for beer contamination.

Plato degrees
The content of extract in the mash is determined by the saccarometer at 20°C with the Plato scale. The Plato scale can be converted into alcohol levels with the conversion scale.