Water

Question 1

Test

Answer 1

Test

Question 2

What can seep into the ground and become ground water?

Answer 2

Surface water

Surface water can infiltrate through rock and soil layers.

Question 3

What is the typical pH range of ground water?

Answer 3

6.5 to 8.5

This pH range indicates the acidity or alkalinity of ground water.

Question 4

How long can ground water remain underground?

Answer 4

Thousands of years

Ground water can be subjected to high temperatures and pressures over this duration.

Question 5

What can cause minerals and metals to leach into ground water?

Answer 5

High temperatures and pressures

These conditions affect the minerals and metals present in the surrounding rocks.

Question 6

What does the composition of ground water depend on?

Answer 6

Rock or sand composition

The minerals in the ground water are influenced by the geological materials it passes through.

Question 7

What factors can cause variations in mineral composition and water hardness?

Answer 7

Topography and geology

These geographical factors influence whether the primary water source is surface or ground water.

Question 8

What determines water hardness?

Answer 8

Levels of calcium (Ca2+) and magnesium (Mg2+) compounds

A high concentration of these compounds leads to ‘hard’ water.

Question 9

What characterizes ‘soft’ water?

Answer 9

Low levels of calcium (Ca2+) and magnesium (Mg2+)

Soft water is less mineral-rich compared to hard water.

Question 10

What has contributed to the fame of some brewing locations?

Answer 10

Their water quality and suitability for particular beer styles

The composition of water plays a crucial role in brewing.

Question 11

Fill in the blank: The ideal composition of water used for beer styles is covered in the lesson dealing with the effects of water quality on _______.

Answer 11

beer

Water quality is critical in the brewing process.

Question 12

What are the potential sources of a municipal water supply?

Answer 12

A mixture of several sources, each with different mineral compositions.

Question 13

How can a municipal water supply be provided to a community?

Answer 13

Blended into one source or alternating sources supplying different compositions at different times.

Question 14

What is a significant challenge for brewers regarding municipal water supply?

Answer 14

They will need to adjust their water treatment or mineral additions accordingly.

Question 15

What is the main advantage of municipal water supply?

Answer 15

It should comply with local drinking legislation, thus would be potable.

Question 16

Why is municipal water likely to be chlorinated?

Answer 16

To meet microbiological standards.

Question 17

What must brewers do to the chlorinated water before brewing?

Answer 17

Remove the chlorine.

Question 18

What off-flavour can chlorine in brewing water cause?

Answer 18

Chlorophenol.

Question 19

What can high levels of chlorine damage in brewing?

Answer 19

Membrane filters.

Question 20

What must breweries do if they utilize water directly from surface or ground water?

Answer 20

They may need to install equipment to meet potability standards.

Question 21

What is the main purpose of purifying water?

Answer 21

To meet potability standards.

Question 22

What are the two main sources of raw water?

Answer 22

• Surface water
• Groundwater

Question 23

What is the role of storage reservoirs in water treatment?

Answer 23

They blend water from different sources and allow contaminants to settle.

Question 24

What is the process of screening in water treatment?

Answer 24

Filtering water through metal grills and screens to remove solid objects.

Question 25

What is coagulation in water treatment?

Answer 25

The process of adding a chemical coagulant to bind fine suspended materials.

Question 26

What is the purpose of sedimentation in water treatment?

Answer 26

To allow suspended solids to settle out of the water.

Question 27

What is the purpose of aeration in water treatment?

Answer 27

To remove volatile organics, carbon dioxide, and some taste and odorous compounds.

Question 28

Why is pH adjustment important in water treatment?

Answer 28

To meet water quality standards and avoid corrosion or scaling.

Question 29

What acids can be used to lower the pH of water?

Answer 29

* Sulphuric acid (H2SO4) * Hydrochloric acid (HCl)

Question 30

What alkaline chemicals can be used to raise the pH of water?

Answer 30

* Sodium hydroxide (NaOH) * Sodium carbonate (Na2CO3)

Question 31

What is the recommended pH for effective disinfection of drinking water according to the World Health Organisation?

Answer 31

Less than 8.0 ## Footnote The pH level is crucial for chlorine effectiveness in disinfection.

Question 32

What risks are associated with excessive chlorine in drinking water?

Answer 32

Undesirable taste, odours, and corrosion risk ## Footnote Managing chlorine levels is important for palatability and safety.

Question 33

List three advantages of chlorine treatment.

Answer 33

* Low initial cost * Low running costs * Simplicity of handling ## Footnote These factors contribute to chlorine’s popularity in water treatment.

Question 34

What is the molar mass of calcium? What is the molar mass of magnesium? How are these used to calculate total water hardness?

Answer 34

Calcium mm: 2.5 Magnesium mm: 4.1 Equation Total hardness mg/l = (2.5xCa) + (4.1xMg)

Question 35

What is the effect of chloride in beer?

Answer 35

Gives beer body and fullness, with a level of sweetness ## Footnote Some brewers believe chloride enhances the overall mouthfeel of the beer.

Question 36

What role does sulphate play in beer flavor?

Answer 36

Increases the perception of bitterness and gives a dry finish ## Footnote Sulphate is often associated with a sharper taste in beer.

Question 37

What ratio of chloride to sulphate is thought to enhance beer’s body and sweetness?

Answer 37

2:1 Chloride to Sulphate ## Footnote This ratio reduces drying, bitterness, and metallic flavors.

Question 38

What type of beers does a 2:1 chloride:sulphate ratio support?

Answer 38

Malty beers ## Footnote This ratio enhances the malt's sweetness.

Question 39

What is the expected outcome of a 1:1 chloride:sulphate ratio?

Answer 39

Balanced beers ## Footnote This ratio provides a harmonious blend of flavors.

Question 40

What type of beer is associated with a 1:2 chloride:sulphate ratio?

Answer 40

Pale Ale/IPA ## Footnote This ratio supports the hops' bitterness.

Question 41

What are some compounds that affect yeast?

Answer 41

Zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), manganese (Mn2+), copper (Cu2+), iron (Fe2+), potassium (K+) ## Footnote These compounds primarily affect yeast enzymes as co-factors.

Question 42

What is the significance of calcium for yeast?

Answer 42

Calcium is essential for yeast flocculation and promotes the binding of yeast cells.

Question 43

What can happen if the required compounds are not available in the right quantities?

Answer 43

It can negatively affect the yeast’s metabolic pathways, causing off-flavours, reduced ethanol production, and poor yeast crops.

Question 44

How can the various compounds found in water affect colloidal stability?

Answer 44

Calcium promotes yeast flocculation, thus helps to remove yeast suspended within the wort/beer, thus clarifying the beer. Calcium and Magnesium improve protein and polyphenol interactions, forming ‘hot break’, which improves wort clarification. Calcium reacts with oxalate to form calcium oxalate, which is precipitated out. This improves wort clarity and prevents gushing (uncontrolled over-foaming of beer). Copper and iron act as an oxidation catalyst, which can negatively affect colloidal stability. Silicate can cause haze when bound to calcium. It can also negatively affect wort run-off separation, causing a more turbid wort and ultimately affecting wort clarity

Question 45

A typical German Weizen and an American IPA can both be pale in colour. Should they use the same type of water profile? Discuss your reasons

Answer 45

No, the water would need to be adjusted slightly, mainly with regards to the chloride:sulphate ratio. Weizen beers tend to have low bitterness and are balanced, so you would expect a chloride:sulphate ratio close to 1:1. However, with an American style IPA, the beer tends to have very high bitterness and so there should be a high level of sulphate, moving the chloride:sulphate ratio closer to 1:3 or even 1:4, to really enhance that bitter flavour. The calcium and alkalinity levels could be similar