smaakstoffen

smaken

ACETALDEHYDE Associated terms• Aldehydic• Bruised apples• Emulsion paint

Present in all beers. Off-flavour at high concentrations. Positive contribution tothe flavour of some beer styles.

Produced by yeast during fermentation. Indicative of high O2levels in packaged beer. Can also beformed by contaminating bacteria

Typical concentration in beer 2 - 15 mg/lApproximate flavour threshold 5 - 15 mg/lBeer Flavour Wheel number 0150

ACETIC Associated terms(acetic acid) • Vinegar

• Acidic

Present in all beers. Off-flavour at highconcentrations.

Produced by yeast in beer duringfermentation. High levels can beproduced in beer by contaminatingacetic acid bacteria

Typical concentration in beer 30 - 200 mg/lApproximate flavour threshold 130 mg/lBeer Flavour Wheel number 0910

ALKALINE Associated terms(sodium bicarbonate) • Detergent-like

• Caustic

Taint in beer. Increases in beer pH valuealso affect beer flavour indirectly, byaltering the flavour activity of manyflavour compounds.

External contamination of beer withcaustic (usually alkaline cleaningagents).

Typical concentration in beer 0 mg/lApproximate flavour threshold 200 mg/lBeer Flavour Wheel number 1310

ALMOND Associated terms(benzaldehyde) • Marzipan

• Bitter almonds

Occasional off-flavour in beer. Flavourimpact character in some fruit beers.

Can be formed in beer during storage.

Typical concentration in beer 1-10 μg/lApproximate flavour threshold 1 mg/lBeer Flavour Wheel number 0224

BROMPHENOL Associated terms(…...........) • Inky

• Old TV set• Museum like• Electric fire

Taint in beer.

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Typical concentration in beer 0 mg/lApproximate flavour threshold 1,3 μg/lBeer Flavour Wheel number ???? ergens bij 0500

BUTYRIC Associated terms(butyric acid) • Rancid

• Baby sick• Putrid

Off flavour in beer.

Formed by bacteria, either during wortproduction, or in sugar syrups duringstorage. Occasionally formed duringbacterial spoilage of packaged beer.

Typical concentration in beer 0.5 - 1.5 mg/lApproximate flavour threshold 2 - 3 mg/lBeer Flavour Wheel number 0614

CAPRYLIC Associated terms(octanoic acid) • Goaty

• Waxy• Tallowy

A desirable flavour character of somepale lager beers. Off-flavour at highconcentrations.

Produced by yeast during conditioning(cellaring) of beer.

Typical concentration in beer 2 - 8 mg/lApproximate flavour threshold 4 - 6 mg/lBeer Flavour Wheel number 0611

CATTY Associated terms(p-menthane-8-thiol-3-one) • Blackcurrant leaves

• Ribes• Tom-cat urine

A catty flavour can often be found in theearly stages of oxidation. It is generallyconsidered to be an off-flavour.However, it is part of the normal flavourprofile of some ales.

Contamination of raw materials with aprecursor of catty aroma.

Typical concentration in beer ? mg/lApproximate flavour threshold 15 ng/lBeer Flavour Wheel number 0810

CHLOROPHENOL Associated terms(2,6-dichlorophenol) • Mouthwash

• Antiseptic• Hospital-like

Taint in beer.

External contamination of brewing rawmaterials and/or packaging materialswith chlorophenols. Contact of beerwith chlorinated liquor.

Typical concentration in beer 0 mg/lApproximate flavour threshold 5 μg/lBeer Flavour Wheel number 0504

DIACETYL Associated terms• Buttery• Butterscotch• Milky

Usually an off-flavour, especially inpale lager beers. Positive contribution tothe flavour of someales and stouts.

Formed in beer from a precursorproduced by yeast duringfermentation. Can also be formedby contaminant bacteria whenhygiene standards are inadequate.

Typical concentration in beer 8 - 600 μg/lApproximate flavour threshold 10 - 40 μg/lBeer Flavour Wheel number 0620

DMS Associated terms(dimethyl sulphide) • Sweetcorn • Tomato sauce

• Creamed corn • Sea vegetable• Cooked vegetable

Desirable characteristic of some palelager beer styles. Off-flavour in somebeers.

Formed from a malt-derived precursorduring wort production. May also beproduced by contaminant bacteriaduring fermentation.

Typical concentration in beer 10 - 150 μg/lApproximate flavour threshold 25 μg/lBeer Flavour Wheel number 0732

EARTHY Associated terms(2-ethyl fenchol) • Damp soil

• Freshly dug soil

Off flavour in beer.

Produced by microorganisms in water.Can also migrate into beer aftermicrobial production in the walls ofdamp cellars

Typical concentration in beer 0 mg/lApproximate flavour threshold 5 μg/lBeer Flavour Wheel number 0841

ETHYL BUTYRATE Associated terms• Tropical fruits• Mango• Tinned Pineapple

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Typical concentration in beer 0,05-0,25 mg/lApproximate flavour threshold 0,4 mg/lBeer Flavour Wheel number ???? ergens bij 0130

ETHYL HEXANOATE Associated terms• Estery• Apple• Aniseed

Present in all beers. Plays an importantrole in overall flavour balance.Concentrations vary considerably frombeer to beer. Off-flavour at highconcentrations.

Produced by yeastduringfermentation.

Typical concentration in beer 0.07 - 0.5 mg/lApproximate flavour threshold 0.2 mg/lBeer Flavour Wheel number 0132

FRESHLY CUT GRASS Associated terms(cis-3-hexenol) • Leafy

• Crushed green leaves• Hedge cuttings

A desirable character of some beers.Off-flavour at high concentrations.

Several types of compounds impartfreshly cut grass flavours to beer. Theirpresence is influenced by wort boilingpractice and hop variety.

Typical concentration in beer ? mg/lApproximate flavour threshold 15 mg/lBeer Flavour Wheel number 0231

GERANIOL Associated terms• Rose-like• Floral• Flower-like• Fruity

Geraniol makes an important contributionto the flavour of some beers. It is partlyresponsible for the floral component ofhop aroma.

Geraniol is imparted to beer via hops. It isan important character of hop oil(essential oil of Humulus lupulus). Itsconcentration in beer is determined bythe hop variety, the hopping regime andby wort boiling and fermentationconditions.

Typical concentration in beer 0 - 100 μg/lApproximate flavour threshold One third of the population have a

threshold of about 18 μg/l. The remainderhave thresholds around 350 μg/l.

Beer Flavour Wheel number 0162

GRAINY Associated terms(isobutyraldehyde) • Green malt character

• Green• Harsh

In the main, an undesirable character,but may feature at a low level in somebeers.

Imparted to beer by the use of barleymalt, and controlled by sparging andwort boiling practices. Also associatedwith use of malts that have not beenstored for long enough before use.

Typical concentration in beer <1 - 20 μg/lApproximate flavour threshold Approximately 10 μg/l (depending on SO concentration)Beer Flavour Wheel number 0310

H2S Associated terms(hydrogen sulphide) • Rotten eggs

• Sulphidic

At low concentrations, H S imparts adesirable fresh flavour to beer. Athigher concentrations it imparts an offflavour.

Produced by yeast duringfermentation and sometimes duringmaturation. Can also be formed bycontaminant bacteria when hygienestandards are inadequate

Typical concentration in beer 0.001 - 0.2 mg/lApproximate flavour threshold 4 μg/lBeer Flavour Wheel number 0721

HOP OIL Associated term(?????) • Hoppy

Key flavour characteristic imparted tosome speciality beers by deliberateaddition of hop oil.

Essential oil of the hop (Humuluslupulus) isolated by steam distillation.

Typical concentration in beer 0.05 - 3 mg/lApproximate flavour threshold 0.16 mg/lBeer Flavour Wheel number 0173

Indole Associated term• Farmyard• Jasmine

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ISOAMYL ACETATE Associated terms• Estery• Fruity• Banana• Peardrop

Present in all beers . Plays an importantrole in the overall flavour.Concentrations vary considerably frombeer to beer. Major flavour impactcharacter of some beers,eg wheat beer.

Produced by yeast duringfermentation.


ISOVALERIC Associated terms(isovaleric acid) • Putrid • Stale cheese

• Old hops • Sweaty

Off-flavour in beer. Flavour impact characterin some beer styles.

Flavour can be imparted to beer through theuse of old or degraded hops, or use of highhopping rates.

Typical concentration in beer 0.2 - 1.5 mg/lApproximate flavour threshold 1 mg/lBeer Flavour Wheel number 0613

KETTLE HOP Associated terms(?????) • Late hop character

• Spicy

A desirable character of some palelager beers

Imparted to beer by the deliberateaddition of a portion of the hop grist(usually 'aroma' hops) to the kettle latein the boil. Alternatively, can be addedbefore packaging in the form of anessence.

Typical concentration in beer 0.01 - 0.2 mg/lApproximate flavour threshold 0.04 mg/l (varies with source)Beer Flavour Wheel number 0171

LEATHERY Associated terms• hay-like• mouth drying

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Typical concentration in beer 0 mg/l in fresh beerApproximate flavour threshold 10 μg/lBeer Flavour Wheel number 0830

LIGHTSTRUCK Associated terms(3-methyl-2-butene-1-thiol) • Skunky

• Sunstruck

Off-flavour in beer.

Formed in beer on exposure to eitherdaylight or artificial light. Beers that havebeen bittered exclusively with chemicallymodified hop bitter acids do not developthis flavour.

Typical concentration in beer 1 - 5 ng/l (beers kept in the dark) 0.01 - 1.5 μg/l (beers exposed to lightApproximate flavour threshold 4 ng/lBeer Flavour Wheel number 0724

MERCAPTAN Associated terms(ethanethiol) • Drains

• Rotten vegetables• Leek-like

Component of the sulphury character ofbeer. Off-flavour when present inexcess.

Formed primarily by yeast duringfermentation. Also produced by yeastautolysis during beer maturation

Typical concentration in beer 0 - 0.5 μg/lApproximate flavour threshold 1 μg/lBeer Flavour Wheel number 0722

METALLIC Associated terms(ferrous sulphate) • Inky

• Blood-like• Tinny

Taint in beer. High concentrations ofmetal ions in beer also affect foamquality and promote the formation ofstale flavours.

Derived from contact of beer withmetal-containing materials (brewingplant, raw materials). Metallic notescan also be derived from lipidoxidation products.

Typical concentration in beer <0.5 mg/l (ferrous ion)Approximate flavour threshold 1 mg/l (ferrous ion)Beer Flavour Wheel number 1330

MUSTY Associated terms(2,4,6-trichloroanisole) • Damp cellar

• Fusty• Cork taint (wine)

Taint in beer. Extremely flavour active.

External contamination of brewing rawmaterials and/or packaging materials.Chloroanisoles can migrate acrosspackaging materials to contaminateprocess aids, raw materials and beer.

Typical concentration in beer 0 mg/l Approximate flavour threshold 25 ng/lBeer Flavour Wheel number 0842

ONION Associated terms(dimethyl trisulphide) • Cooked onion

• Garlic-like

Component of the sulphury character ofpale lager beer. Off-flavour at highconcentrations.

Produced from sulphur-containingamino acids during wort boiling.Purged from beer during fermentationby yeast-derived CO . Also found in hopoil.

Typical concentration in beer 0.05 - 0.3 μg/lApproximate flavour threshold 0.1 μg/lBeer Flavour Wheel number 0736

PAPERY Associated terms(trans-2-nonenal) • Cardboard

• Oxidized

Off-flavour in beer associated withageing.

Formed during beer storage.Development of character depends ontime and temperature of storage, andoxygen content of packaged beer.

Typical concentration in beer <50 ng/l (fresh beer); >0.2 μg/l (aged beer)

Approximate flavour threshold 50 - 100 ng/lBeer Flavour Wheel number 0820

PHENOLIC Associated terms(4-vinyl guaiacol) • Spicy

• Herbal• Clove-like

Usually an off-flavour. Major flavourimpact character of some products,wheat beers.

Produced by wild yeasts or specialityyeasts.


PLASTICS Associated terms• burning plastic• Polystyrene• Styrene

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SALTY Associated terms(sodium chloride) • None

Contributes to the overall taste balanceof beer.

Contributed to beer by both malt andbrewing liquor. Some brewers add saltsdirectly to the process stream, eg inmashing or wort boiling.

Typical concentration in beer < 100 mg/lApproximate flavour threshold 200 mg/lBeer Flavour Wheel number 1100

SMOKY Associated terms(guaiacol) • Smoked bacon

• Smoked herring (kippers)

A desirable character in some types ofbeers, especially Rauchbiers (smokedbeers). Off-flavour in pale lager beers

Contributed to raw materials (malt,adjuncts etc) by exposure to smoke.Flavour is then extracted duringmashing or wort boiling.Occasionally formed by bacterial actionduring fermentation.


SOUR Associated terms(citric acid) • Acidic

• Lemon• Sour milk

All beers are acidic. In excess, thisimparts an undesirable flavour andmouthfeel. Beer pH indirectly influencesthe flavour activity of a number of beercomponents.

Raw materials. Fermentation.Bacterial contamination of product orprocess. Poor hygiene control.

Typical concentration in beer 90 - 300 mg/lApproximate flavour threshold 170 mg/lBeer Flavour Wheel number 0920

SPICY Associated terms(eugenol) • Eugenol

• Allspice• Clove oil

Off-flavour in pale lager beers. Impactcharacter in certain beers of highalcohol content (>7% vol/vol).

Formed during ageing of beer.

Typical concentration in beer 10 - 30 μg/l in normal beer, >40 μg/l in problem beers

Approximate flavour threshold 40 μg/lBeer Flavour Wheel number 0111

SULPHITIC Associated terms(sodium sulphite) • Sulphur dioxide

• Striking match• Choking

Associated with the presence ofsulphites in beer. Sulphites interact withother flavour compounds in beer,including acetaldehyde and carbonylcompounds, to mask their flavour.

Sulphites may be added to beer as anantioxidant or preservative. Lager yeastsnaturally produce sulphite duringfermentation.

Typical concentration in beer <10 mg/lApproximate flavour threshold 7 mg/lBeer Flavour Wheel number 0710

VANILLA Associated terms(vanillin) • Custard-like

• Cream-soda• Ice cream

Imparts a positive aroma to some beerstyles. Formed in some beers duringageing.

Derived from breakdown of barley cellwall materials. Can also be formedfrom the breakdown of certain phenolicflavour compounds produced by wildyeasts.


important factors:– wort: gravity, PH, dissolved oxigen, yeast food– fermentation : temperature, pressure– yeast: strain, pitching rate, contaminants

increasing yeast pitching rate:ethyl acetaat ++isoamylacetate --higher alcohols --

increasing wort oxygenation:higher alcohols ++esters --SO2 --acetaldehyde --diacetyl --

increasing fermation temperature:higher alcohols ++esters ++SO2 ++acetaldehyde ++diacetyl ++

increasing fermation counter-pressure:less yeast growthdissolved CO2 ++acetaldehyde ++diacetyl ++esters --higher alcohols --

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