Cooling, Carbonating And Blending

Question 1

Why we cool beer

Answer 1

1. Prepare the wort for fermentation
2. Prepare the beer for cold maturation
3. Prepare the beer for filtration
4. Prepare the beer for carbonation
5. Maintain the temperature during a specific step that may warm the beer.

Question 2

Plate heat exchanger

Answer 2

Most common heat exchanger, series of plates, hot fluid in, cold fluid out.

Question 3

Shell and tube heat exchanger

Answer 3

Tubes (contained within the shell) rather than plates seperate coolant from the hot liquid. Beer runs through tubes while coolant runs through the shell

Question 4

Counter current flow

Answer 4

Coolant flows opposite to the hot/warm beer, often the temp of the beer leaving the HX is lower then the coolant entering it = risk of beer reaching its freezing point.

Question 5

Co-current flow

Answer 5

Useful when cooling beer a few degrees, eg when approaching the freezing point of beer. Beer will not be cooled to less than the temp of the coolant, ie will never freeze. Not as efficient, greater load on refrigeration.

Question 6

Double stage cooling

Answer 6

• Hot beer passes through zone 1, where coolant significantly lowers its temp
• cooled beer passes through zone 2, where coolant adjusts the temp to desired value.
• greatly reduces risk of freezing beer in the HX

Question 7

Carbonation ranger in deferent beers

Answer 7

Vol co2/. g co2
Scottish Ales 0.75-1.3. 1.5-2.6
Irish Stouts. 1.0-1.5. 2.0-3.0
British Brown Ales1.5-2.3. 3.0-4.6
American IPAs 2.0-2.5. 4.0-5.0
Czech Lagers. 2.0-2.5. 4.0-5.0
American Lagers. 2.6-2.8. 5.2-5.6
Gose and Sours. 3.3-4.5. 6.6-9.0
Weissbier. 3.5-4.5. 7.0-9.0

Question 8

Carbonation: temperature influence

Answer 8

Co2s solubility in beer increases as the temperature decreases

Question 9

Carbonation: pressure influence

Answer 9

Henry’s law: co2 solubility in beer increases as the pressure increases

Question 10

Carbonation: ph influence

Answer 10

Co2 solubility in beer increases as ph increases

Question 11

Carbonation: gravity influence

Answer 11

As gravity increases (viscosity), co2s solubility in beer decreases.

Question 12

Maintaining carbonation

Answer 12

• stable temperature
• stable pressure
• laminar, non turbulent

Question 13

DAW: vacuum deaeration

Answer 13

Hot water sanitises as it’s sprayed into a vacuum vessel, O2 & other dissolved gasses escape easily

Question 14

DAW: Gas stripping

Answer 14

Gas is injected into water until saturated; saturated water is sprayed into the vessel and gas escapes the droplets, also removing O2.

Question 15

DAW: pack-bed gas stripping

Answer 15

Water is sprayed into a packed bed which greatly increases eaters surface area, while N or CO2 flows upwards, knocking O2 out of the water

Question 16

DAW: membrane gaseous exchange

Answer 16

Water passes through a cartridge packed with hollow tubes made of hydrophobic tubes, forcing gas into the tubes, but not the water because there hydrophobic