Sensory training kit used to train professional beer tasters to recognize and scale the intensity of six different beer flavour notes associated with wild yeast, speciality yeast and bacteria.
Use this set of certified beer flavour standards to deliver up to 90 minutes of taster training for ten people, or as a personal flavour training kit, allowing you to train yourself to recognize each of the ten flavour notes over a longer period of time.
The AROXA™ Beer – Yeast and bacteria – Wild, speciality & bacteria kit comes complete with informative flavour cards for each standard.
AROXA™ certified beer flavour standards are: food grade | free from sensory impurities | extensively tested | safe to smell and taste. Unsure whether this kit is right for you? Don’t forget about our 100% satisfaction guarantee.
The importance and origins of each flavour are:
Flavour: ACETIC Chemical name: ACETIC ACID
“Acetic, like vinegar”
IMPORTANCE: Acetic acid is present in all beers. It is the characteristic flavour of some beer styles, eg Lambic beer. It is present in all lagers, ales, stouts and wheat beers as a normal component of a balanced flavour. It becomes and off-flavour when present at high concentrations. Acetic flavour is a common problem in draught-dispensed beers, where it results from growth of contaminating acetic acid bacteria or wild yeasts.
ORIGINS: Acetic acid is present in all beers. It is the characteristic flavour of some beer styles, eg Lambic beer. It is present in all lagers, ales, stouts and wheat beers as a normal component of a balanced flavour. It becomes and off-flavour when present at high concentrations. Acetic flavour is a common problem in draught-dispensed beers, where it results from growth of contaminating acetic acid bacteria or wild yeasts.
Flavour: ETHYL ACETATE Chemical name: ETHYL ACETATE Number of capsules: 2 capsules represent the strength to use in beer
“Ethyl acetate, like nail varnish or nail varnish remover”
IMPORTANCE: Ethyl acetate is present in all beers, and is the ester found in greatest amounts in beer. Its high flavour threshold means that it makes a bigger contribution to the flavour of ales – and especially strong ales – than it does to lagers.ced depends on several variables, including wort composition, yeast strain and fermentation conditions. Wild yeasts produce high levels of ethyl acetate.
ORIGINS: Ethyl acetate is produced by both ale and lager yeasts in the brewery during fermentation. The amount of ethyl acetate produced depends on several variables, including wort composition, yeast strain and fermentation conditions. Wild yeasts produce high levels of ethyl acetate.
Flavour: SPICY Chemical name: EUGENOL
“Spicy, like clove oil or allspice”
IMPORTANCE: Eugenol is a flavour impact character in some beer styles, eg Belgian ales. It is an off-flavour in lager beers. It is more common in beers of higher alcohol content (> 7% vol / vol).
ORIGINS: Eugenol is formed during ageing of beer from precursors which are formed by yeast during fermentation. Formation of eugenol is associated with use of warm fermentation temperatures and typically associated with beers of higher alcoholic strength. Barrel-aged beers can also possess a spicy character from eugenol, deriving this flavour character from the wood.
Flavour: PHENOLIC-4-EP Chemical name: 4-ETHYL PHENOL
“Phenolic-4-EP, like blue cheese or band aid”
IMPORTANCE: Since conventional brewer’s yeast (Saccharomyces) does not produce 4-ethyl phenol, its presence in most beers indicates microbiological contamination.
ORIGINS: 4-Ethyl phenol is produced by contaminant Brettanomyces (Dekkera) yeasts and, occasionally by lactic acid bacteria, during beer production. Beers which are low in sulphur dioxide are particularly sensitive to growth of such microorganisms. Produced by Brettanomyces yeasts during or after fermentation. In most beers, Brettanomyces is a contaminant. 4-Ethyl phenol is an off-flavour in such beers. Some beers styles rely on flavours produced by Brettanomyces for their distinctive character.
Flavour: INDOLE Chemical name: INDOLE
“Indole, like pig faeces or jasmine”
IMPORTANCE: Indole is an off-flavour in lagers, ales and stouts. It is regarded by some as ‘artisanal’ character (‘jasmine / floral’) and by others as a serious off-note (‘faecal / dirty’).
ORIGINS: Indole is formed by contaminant ‘coliform’ bacteria during fermentation. It is often associated with simultaneous production of dimethyl sulphide.
Flavour: ISOVALERIC Chemical name: ISOVALERIC ACID
“Isovaleric, like cheese or sweaty socks”
IMPORTANCE: Isovaleric, sweaty, cheesy flavour notes are characteristic flavours of some beer styles, eg India Pale Ale. Typical ‘cheesy’ characters are often associated with beers of very high bitterness. In pale lager beers, isovaleric character is regarded as an off-flavour.
ORIGINS: Isovaleric acid is derived from breakdown of alpha-acids in hops. It is imparted to beer by use of high hopping rates or degraded hops or hop extracts. Isovaleric acid can occasionally be produced by wild yeasts, specifically Brettanomyces spp. which may be present either as contaminants or introduced into beer for conditioning purposes.
Flavour: LACTIC Chemical name: LACTIC ACID
“Lactic, like yoghourt or sour milk”
ORIGINS: Lactic acid has several origins. Low levels are derived from malt, brewhouse acidification, and fermentation. Higher levels are associated with growth of lactic acid bacteria in beer (Lactobacillus, Pediococcus).
Flavour: PLASTIC Chemical name: STYRENE
“Plastics, like polystyrene or model aeroplane glue”
IMPORTANCE: Styrene can be both an off-flavour and a taint in beer. It is associated with a moderate degree of consumer rejection in beer. It can be described by consumers as ‘chemical’, ‘plasticy’ or ‘contaminated’.
ORIGINS: Styrene is produced by contaminant wild yeasts during fermentation. It can also be introduced into beer as a taint through use of contaminated packaging materials or defective carbon dioxide gas.
Flavour: VANILLA Chemical name: VANILLIN
“Vanilla, like vanilla pods, ice cream or custard”
IMPORTANCE: Vanilla is a positive flavour note found in some speciality ales and stouts. It imparts a creamy aroma and contributes to a smooth mouthfeel, reducing the harshness of components derived from roasted malts.
ORIGINS: Vanilla flavour notes arise in beer in several ways – ageing on wood; addition of flavour essences; the action of wild yeasts; and breakdown of certain phenolic compounds during beer storage.
Flavour: PHENOLIC-4-VG Chemical name: 4-VINYL GUAIACOL
“Phenolic-4-VG, like cloves or carnations”
IMPORTANCE: 4-Vinyl guaiacol is a key flavour impact character in some ales and stouts. It is regarded as an off-flavour in lager beers when it is associated with a moderate degree of consumer rejection. 4-Vinyl guaiacol is a signature flavour character in German-style wheat beer, together with the ester isoamyl acetate.
ORIGINS: Low levels of 4-vinyl guaiacol are produced through a combination of enzymic and non-enzymic process during wort production. High levels of 4-vinyl guaiacol result from the use of speciality yeast strains or contamination of beer with wild yeasts.