The importance and origins of each flavour are:

Flavour: WOODY-PINE RESIN    Chemical name: ALPHA PINENE

“Woody-pine resin, like a pine forest, resinous”

ORIGINS: Hop varietal characteristic. Particularly associated with traditional North American hop varieties.

Flavour: ROTTEN VEGETABLE    Chemical name: DIMETHYL DISULPHIDE

“Rotten vegetable, like pickled vegetables or a sewage treatment plant”

IMPORTANCE: Dimethyl disulphide (DMDS) is an off-flavour in fresh beer. It also develops in some beers during ageing in pack. It can also occasionally arise as a taint through use of contaminated carbon dioxide for carbonation of beer. Some describe this flavour as ‘dirty sulphur’.

ORIGINS: Dimethyl disulphide is formed in beer as a result of production of hydrogen sulphide by yeast. If venting of the fermenter is poor (or the fermentation is done under pressure) flavours like this can build up.

Flavour: ONION    Chemical name: DIMETHYL TRISULPHIDE

“Onion, like fried onion or garlic”

IMPORTANCE: Onion flavour from dimethyl trisulphide is a desirable hop-derived flavour note in some ales. As an off-flavour it is formed during ageing in package of pale lager beers. It can also be found in fresh lager beer as a result of wort boiling practices (specifically, lack of boil vigour in all-malt worts).

ORIGINS: Although produced from amino acids during wort boiling most dimethyl trisulphide is formed during storage of packaged beer. Some hops impart this character when used post-fermentation.

Flavour: ORANGE-LIMONENE    Chemical name: D-LIMONENE

“Orange-limonene, like fresh orange juice”

ORIGINS: Hop varietal characteristic. Present in hops and extracted into wort or beer. The majority of citrus-limonene flavor in beer is extracted directly from hops during wort boiling, or through dry hopping during or after fermentation.

Flavour: CITRUS-LINALOOL    Chemical name: LINALOOL

“Linalool, like coriander”

Flavour: FLORAL-LAVENDER    Chemical name: LINALYL ACETATE

“Floral-lavender, like lavender or Earl Grey tea”

ORIGINS: During fermentation, brewer’s yeast can convert linalool into linalyl acetate, causing the development of floral-lavender flavour notes in beer.

Flavour: CITRUS GRAPEFRUIT    Chemical name: 3-MERCAPTOHEXANOL

“Grapefruit, like grapefuit juice or rhubarb”

Flavour: BOILED CABBAGE    Chemical name: METHYL THIOACETATE

“Sulphitic, like burning sulphur or young white wine”

IMPORTANCE: Methyl thioacetate is a positive sulphury flavour note in some lagers. It can be perceived as an off-flavour in other lagers and in all ales and stouts.

ORIGINS: Methyl thioacetate is produced by lager yeast (but not by ale yeast) during fermentation. The amount produced depends on wort composition, yeast strain and fermentation conditions.

Flavour: MERCAPTAN    Chemical name: METHANETHIOL

“Mercaptan, like drains or soft white cheese”

IMPORTANCE: Methanethiol is a component of the sulphury flavour character of beer. It is found in all beer styles to a degree. Methanethiol and other thiols are off-flavours when present in excess.

ORIGINS: Methanethiol arises through yeast autolysis at the end of fermentation or during maturation. It can also be contributed to beer by dry hopping and by growth of bacteria in beer.

Flavour: CARDAMOM    Chemical name: TERPINYL ACETATE

“Cardamom, like cardamom pods or pine furniture”