Faults

Question 1

Acetaldehyde

Answer 1

Aroma - Green Apple/Fresh Pumpkin

Cause - produced by yeast during fermentation, hasn’t been laggered long enough

Question 2

Diacetyl

Answer 2

Aroma - Buttered Popcorn/butterscotch

Cause - during early fermentation, usually gets rectified by end of fermentation, if fermentation gets “stuck” results in lots of diacetyl (can be rectified out)

Question 3

Dimethyl Sulfide (DMS)

Answer 3

Aroma - Cooked Corn (dark beer tomato)

Cause - produced early in fermentation blows off by the end. Darker roast on malt produces less dms. Could also be bacterial infection

Question 4

Trans-2 Nonenal

Answer 4

Aroma - wet cardboard, oxidation

Cause - oxidation of beer

Question 5

Acetic

Answer 5

Aroma - vinegar

Cause- secondary fermentation by bacteria