Lesson 5 - Wort Boiling Technology and Process Control SAQ Flashcards
(21 cards)
What effect does a low difference in temperature between the wort and the steam have on fouling?
Reduces fouling
A lower temperature reduces the likelihood of material cooking onto the heating surface.
Using the equation Q=UAΔT, what happens to ΔT if the heating surface area A is increased while Q and U remain constant?
ΔT decreases
This indicates that a larger heating surface area results in a smaller temperature difference.
How does increased fouling affect the overall heat transfer coefficient?
Reduces it
Fouling acts as an insulator, making heat transfer less efficient.
Is it vital to evaporate water during wort boiling to reduce DMS?
False
Other methods, such as gas sparging or wort stripping, can also remove DMS.
Does wort stripping with steam increase thermal load?
True
It increases the amount of heat the wort is exposed to.
What are the three modes of wort boiling?
Film boiling, Forced convection, Nucleate boiling
Each mode has different effects on heat transfer and wort quality.
Which mode of wort boiling is considered the best?
Nucleate boiling
It effectively achieves the objectives of wort boiling.
What characterizes film boiling?
High temperature difference and steam bubbles blanket the surface
It reduces heat transfer efficiency and increases fouling.
What is the main advantage of forced convection in wort boiling?
High wort velocity aids heat transfer
Turbulent flow improves heat transfer but risks shear on trub particles.
How does nucleate boiling improve heat transfer?
Steam bubbles create turbulence and move heat away from the heating surface
This allows unheated wort to contact the heating surface.
What is a thermosyphon in the context of nucleate boiling?
A mixture of steam bubbles and wort that maintains flow through the calandria
It eliminates the need for a pump.
What is one way to reduce energy used in wort boiling without affecting quality?
Introduce dynamic low pressure boiling
This involves modifying the kettle to handle pressures above atmospheric.
How can a vapour condenser help in wort boiling?
Recovers energy from vapour to pre-heat wort
It reduces energy required for boiling successive brews.
What is the role of gas sparging in the wort kettle?
Removes volatiles without requiring thermal energy to boil
This significantly reduces energy use.
What is the purpose of a vacuum evaporator in the brewing process?
Reduces evaporation needed during the boil
This leads to lower energy consumption.
What are two design aspects that can optimize internal calandrias?
Wort spreader design, Tube diameter
These modifications can enhance boiling efficiency.
What feature does the Krones Stromboli use to reduce foaming during boiling?
Upper deflector
It works with pumped flow to manage wort distribution.
What advantage does the Briggs Symphony external calandria have?
Large heating surface area and low temperature difference
This minimizes negative effects on foam and flavor stability.
What is meant by ‘two-phase flow’ in the context of nucleate boiling?
A mixture of liquid (wort) and gas (vapour)
It results from steam bubble formation and aids in heat transfer.
What is a key benefit of using a vapour condenser with thermal vapour recompression?
Converts vapour from the boil into usable steam
This further recovers energy for wort boiling.
What can be done to optimize the boiling process in terms of evaporation rates?
Control boiling phases to maximize trub formation and volatile removal
This approach minimizes thermal energy needed.
