Raw Materials Off Flavours

Question 1

Spicy

Answer 1

Descriptor: dry, wood

Cause: sesquiterpine oxidation, a-humulene, noble, spicy hops: saaz, tettnanger,

Appropriate: Czech Pilsner

Question 2

Geraniol

Answer 2

Descriptor: floral, rose, fruity

Cause: oil from hops located in lupus in glands: fuggle, ekg, British

Appropriate: ESB, British beers

Question 3

Beta Demascenone

Answer 3

Descriptor: dark red berries

Cause: hops- aged in beer, intensity increases with age, stale highly hopped beer - more commonly NA beers

Appropriate: ipas, pale ales, esb, bitters

Question 4

Bitter

Answer 4

Descriptor: iso alpha acid, ipa like

Cause: age of hops, when added, type of hop, roast malts, sulphate/chloride ratio, iso alpha acid

Appropriate: all beers, min 10 IBU

Question 5

Isovaleric

Answer 5

Descriptor: cheese

Cause: breakdown of alpha acids, hops left out in heat and oxygen, reduce with proper storage

Appropriate: never, in barrel ferments and lambics beyond the cheese smell. Brett can reduce the amount in beer

Question 6

3 methyl 2 butene 1 thiol

3MBT

Answer 6

Descriptor: light struck, skunk

Cause: sunlight (300-500nm) with riboflavin (b2) and iso alpha acids

Appropriate: corona at low levels

Question 7

Catty

Answer 7

Descriptor: black currant, Tom cat urine

Cause: compound in citra hops, predominantly hops varieties 98%, rare to see in malt - contaminated with mesityl oxide

Appropriate: ipas

Question 8

Salt

Answer 8

Descriptor: salty, malty

Cause: sodium chloride or calcium chloride. Common in malt forward beers.

Appropriate: low levels is perceived as malty and can be used to balance bitterness, 30 ppm minimum chloride to make a difference

Question 9

Astringent

Answer 9

Descriptor: dry, tannic

Cause: tannins, dark malts, oversparging, over crushing, excessive hopping, fruits in beers, polyphenols from acetobactor

Appropriate: wild ferment beers, BJCPStyles says none, could be there to balance sweetness

Question 10

Vanilla

Answer 10

Descriptor: vanilla, vanillin

Cause: wood (barrels), additions of essences, wild yeasts, breakdown of phenolic compounds

Appropriate: spiced beers like porters, stouts, other specialty beers.

Question 11

Alkaline

Answer 11

Descriptor: detergent like, caustic

Cause: didn’t rinse caustic enough, incorrect brewing salts, high ph

Appropriate: never, dump

Question 12

Isobutyraldehyde

Answer 12

Descriptor: green malt character, harsh green

Cause: grains that haven’t been stored long enough, excessive runoff, poor wort boil, boiling husks

Appropriate: no beers above threshold