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2. Metallic Is very difficult to detect Is much easier to taste than to smell Easy trick – Make a fist and rub the beer on the base of thumb where it meets your forefinger

3. Phenolics Chemical compound is 4-vinylguiacol Most often smells like cloves Comes from removing C0 2 from ferulic acid which is found in the cell wall of cereals

4. Sour (Acidic) Results because of low pH Darker malt = lower pH Higher calcium= lower pH Vigorous and extensive fermentation = lower pH Bacteria present = lower pH pH < 4 – sharper, increased dryness pH < 3.7 – metallic finish High bicarbonate = high pH High malt bill = higher pH High gravity = higher pH pH > 4.4 – soapy, caustic, biscuit & toast finish

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6. DMS Comes from an amino acid in malted barley With longer germination times, the kernel becomes more sensitive to heat This is more readily seen in lighter malts such as pale malt and pilsner malt

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10. Acetaldehyde Produced my yeast Comes in the later stages of sugar break down It is the immediate precursor of ethanol – This is the result of poor performing yeast

11. Off Flavours