Maturation

Question 1

Warm maturation

Answer 1

Occurs immediately after fermentation; beer is held at similar temps to fermentation, allows flavors to stabalize

Question 2

Cold maturation

Answer 2

Occurs after warm maturation; primarily ensures beer doesn’t develop unwanted haziness, beer is chilled and kept for ~3 days “lagering” or “conditioning”

Question 3

Stabalizing

Answer 3

Ensures the degree of haze remains constant

Question 4

Bottle & cask conditioning

Answer 4

When fermentation is close to completion, green beer is transferred to package, where maturation occurs. Naturally carbonated and clarified in packaging.

Question 5

Stoke’s Law

Answer 5

Dictates the rate of settling increases when:
-Particles are large and dense
-Beer is stored in a shallow vessel rather than a deep one
-Force of gravity is increased (eg in a centrifuge)
-The liquid is less dense

Question 6

Haze: Solutions

Answer 6

Solids that have dissolved completely will appear clear, have no degraded or formed new compounds

Question 7

Haze: Colloids

Answer 7

Solids too large to dissolve for a colloid; buoyancy causes them to remain suspended in the liquid eg: milk, will appear opaque

Question 8

Haze: suspended solids

Answer 8

Initially opaque, but will settle out eventually eg: dirt in water. Particles exceed 1 micrometer and will not keep floating

Question 9

Biological haze

Answer 9

Yeast, bacteria

Question 10

Non-biological haze

Answer 10

Unfermentable sugars, B-Glucans (cell wall compounds), lipids, oxalates (salts from malts)

Question 11

Chill haze

Answer 11

Formed when polyphenols (malt during mash, hops during boil) and proteins (malt) interact

Question 12

How does chill haze become permanent haze?

Answer 12

Polyphenols become oxidized and interact with proteins and create a complex that is too large to be soluble. Over time, the complexes become larger and larger and become less soluble, even at warmer temps.

Question 13

Stabilizing agents

Answer 13

Increase the clarity and shelf life of a beer; interacts with haze precursors to form large particles which are removed by filtration or sedimentation

Question 14

Finings

Answer 14

Will remove haze from metal ion contamination, bacteria, non-viable yeast, wild yeast. Eg isinglass, gelatin

Question 15

PVPP Polyvinylpolypyrrolidone

Answer 15

Synthetic nylon polymer that mimics a protein, removes polyphenols

Question 16

Silica gel

Answer 16

Adsorbs proteins by electrostatic attractions, absorbs proteins into pores within the structure of the silicate; removes proteins

Question 17

Polysaccharide gums

Answer 17

Interacts with both proteins and yeast, forming complexes that precipitate; removes yeast and proteins

Question 18

Tannic acid

Answer 18

Polyphenol that binds to proteins to form a haze that can sediment out; removes proteins

Question 19

Proteolytic enzymes

Answer 19

Plant derived enzyme, breaks down proteins into smaller segments, which don’t form haze when they bind to polyphenols

Question 20

Unitank

Answer 20

Fermentation, warm maturation, cold maturation

Question 21

Dualtank

Answer 21

Beer transferred to a separate maturation vessel

Question 22

Horizontal tanks

Answer 22

Cold maturation; require less height, settles out better than vertical tanks because less distance

Question 23

Bottle and cask conditioning

Answer 23

Beer removed from FV and sent to package and analyzed based on its need for additives