fermentation biproducts

Question 1

diacetyl increase

Answer 1

yeast strain, + yeast pitching, + O2,

Question 2

Diacetyl decrease

Answer 2

+ fermentation temp, +[yeast]

Question 3

Diacetyl precursor

Answer 3

acetolactate

Question 4

diacetyl advancement to a higher threshold

Answer 4

2,3 Butanediol

Question 5

Acetylaldehyde (ethanal) increased by

Answer 5

rapid fermentation, + temp, + pressure, low O2, infected wort

Question 6

Acetylaldehyde (ethanal) decreased by

Answer 6

Good second fermentation, warm maturation, good wort O2, +[yeast]

Question 7

Acetylaldehyde is from

Answer 7

Pyruvate -> pyruvate decarboxylase -> ethanal +CO2

Question 8

Sulphur Increased by

Answer 8

Absence of yeast growth

Question 9

Sulphur decreased by

Answer 9

+ferm temp, is scrubbed out by active fermentation.

Question 10

Esters Increased by

Answer 10

+[wort], +fermentation temp, low O2, low pitching rate

Question 11

esters decreased by

Answer 11

• [wort], -fermentation temp, +O2, low yeast growth

Question 12

Higher Alcohols increased by

Answer 12

+ ferm temp, low FAN, +O2, + [wort]

Question 13

Higher Alcohols decreased by

Answer 13

+ yeast pitching rate, - fermentation temp, good FAN levels