Lager Yeast

aka “Saccharomyces pastorianus”, “S. pastorianus”, “Saccharomyces carlsbergensis” or “Saccharomyces monacensis”, “bottom-fermenting yeast”. Saccharomyces pastorianu named in honour of Louis Pasteur, is the yeast that we commonly refer to as “bottom-fermenting” lager yeast. Genetically ale yeasts and lager yeasts are very closely related. So closely in fact that they are often considered to be members of […]

Organic Acids

The most important organic acids found in beer are acetic, citric, lactic, malic, pyruvic and succinic acids. Organic acids gives a “sour” or “salty” taste to beers. Some of these organic acids are derived from malt and are present at low levels in wort, with their concentrations increasing during fermentation.

Wild Yeast

While wild yeast is sometimes intentionally catered for and wanted (see brett), there are several species that can negatively affect beer. Among non-Saccharomyces wild yeast, those such as Pichia, Rhodotorula, Kluyveromyces, and Candida can negatively affect the quality of beer by causing haze or a film on the surface. Additionally, they may produce off-flavors such […]

Phenols

Phenols is a group of molecules that contribute phenolic flavors and aromas. Phenol is always present in beers, in the form of polyphenols such as tannins. Polyphenols are derivatives of hops and malt, and contribute to a dry mouthfeel. Some (sometimes) wanted phenols are 4VG (clove, spicy, herbal), 4-EP (farmyard, medicinal, mice) and 4-ethylguaiacol (smoked […]

Brettanomyces

Brettanomyces, often referred to as “Brett”, is a family of yeasts. Brettanomyces is often considered a contaminant, giving a beer some “funky”, sour flavors. They are however essential to brewing sour styles such as Lambic and Gueuze and sometimes present in other styles such as saisons, farmhouse, Oud Bruid and Flanders red ales. There are […]

Saccharomyces

Saccharomyces, “sacc”, “sacch”, is a family of yeasts that ferments maltose sugars to create alcohols and CO2. Saccharomyces cerevisiae, “the sugar fungus of the beer”, is the family of yeasts that we commonly refer to as “top-fermenting” ale yeasts. Saccharomyces pastorianus, named in honour of Louis Pasteur, is the yeast that we commonly refer to […]

RDWHAHB

Relax, Don’t Worry, Have A Homebrew We all mess up, either through misunderstanding something, through clumsyness or through the lack of equipment or facilities. Personally I always screw something up while brewing, be it forgetting to shut a tap, forgetting to add something or simply making a mess. I usually ferment to hot (living in […]

Esters

Esters is a large (largest?) group of flavor compounds, in beer usually contributing fruity aromas and flavors. Esters can come in the form of hop essential oil sulfurs, or be formed during the fermentation. While most beer yeast has been selected for producing as few off-flavors as possible, Belgian and Bavarian (banana, clove) yeast is […]

Fatty Acids

Fatty acids are minor constituents of wort and increase in concentration during fermentation and maturation. They give rise to “goaty”, “soapy”, or fatty flavors and can cause a decrease in beer foam stability.

Organic Acids

The most important organic acids found in beer are acetic,citric, lactic, malic, pyruvic and succinic acids. They confer a “sour” or“salty” taste to beers. Some of these organic acids are derived frommalt and are present at low levels in wort, with their concentrationsincreasing during fermentation.