Wort cooling systems

Question 1

What are coolships?

Answer 1

Very large, shallow vessels used to rapidly cool wort

Achieved a fast temperature drop due to large surface area allowing good evaporative cooling.

Question 2

How long can coolships cool wort?

Answer 2

Up to 12 hours

This duration is incomparable to today’s technology and efficiencies.

Question 3

What is evaporative cooling?

Answer 3

Latent heat is transferred from the wort to the moisture in the air as steam rises via evaporation

Only occurs during a change of phase without a change in temperature.

Question 4

What is latent heat?

Answer 4

The heat needed to achieve a change in phase without a change in temperature

Also referred to as ‘hidden’ heat energy.

Question 5

What is sensible heat?

Answer 5

Heat transfer where there is no change of phase, but there is a change in temperature

We feel a temperature change with sensible heat.

Question 6

Where were coolships typically located in a brewery?

Answer 6

At a high point with good airflow over the wort

Often used in combination with an open trickle cooler.

Question 7

What is the temperature at which wort would run over an open trickle cooler?

Answer 7

About 40°C

This step follows the cooling in the coolship.

Question 8

What are some other evaporative cooling technologies?

Answer 8

Falling-film evaporators, steam stripping columns, vacuum evaporators

These have higher energy requirements and can significantly change wort composition.

Question 9

What is a dynamic coolship?

Answer 9

A later design of the coolship that uses a smaller closed vessel and gentle whirlpool action to enhance evaporation

It does not require additional energy.

Question 10

How can evaporative cooling be made more effective?

Answer 10

By:
* Lowering ambient humidity
* Decreasing atmospheric pressure
* Increasing surface area of evaporation
* Choosing different evaporative media
* Adding air movement

These factors enhance the evaporation process.

Question 11

What hygiene challenges did traditional wort cooling systems face?

Answer 11

Hygiene would have been a big challenge by today’s standards

These systems were used for specific beer styles, such as classic lambic beers.

Question 12

What are three key improvements of modern wort cooling systems over coolships?

Answer 12

1. Use of a separate refrigeration system
2. Use of a closed system for easy cleaning
3. Very rapid cooling to maintain productive cycle times

These improvements enhance efficiency and cleanliness.