Chapter 2: Preparing Raw Materials Containing Fermentable Sugars

Question 1

Explain how photosynthesis works.

Answer 1

Plants use the energy from sunlight to convert water and carbon dioxide (CO2) into sugar and oxygen.

Question 2

In what part of the plant does photosynthesis mostly take place in?

Answer 2

The leaves.

Question 3

Which two types of sugar are made in plants during photosynthesis?

Answer 3

Glucose and fructose.

Question 4

How is sucrose made in plants?

Answer 4

By bonding together one molecule of glucose and fructose.

Question 5

How does a plant use the sugars it produces? (2)

Answer 5

1. It combines the sugars with other nutrients they take up from the roots to build plant structures.
2. Sugar is an efficient way to store energy.

Question 6

Why does yeast require sugar in order to create alcohol?

Answer 6

Sugar is the energy source that yeast uses to create alcohol during fermentation.

Question 7

What are the 2 problems a distiller faces when handling a raw material that is full of sugar?

Answer 7

Spoilage and oxidation.

Question 8

Explain how a raw material containing sugar might become spoiled? (2)

Answer 8

1. Loss of yield caused by animals and microorganisms eating the raw material.
2. Partly eaten raw materials run the risk of being tainted and rendered unusable. Typically caused by fungi and bacteria.

Question 9

Explain oxidation.

Answer 9

Oxygen reacts with raw materials (fruits, sugar cane) and with the juices they release causing a loss in (1) sugar yield and (2) inidentifiable and expressive aromas.

Question 10

Give an example of oxidation.

Answer 10

When you bite into an apple the area exposed becomes brown and starts to lose its freshness, ultimately tasting unpleasant.

Question 11

What preservative chemical might be used in cider and wine production to protect fruit juice from spoilage and oxidation?

Answer 11

Sulfur dioxide (SO2).

Question 12

Why is it not advisable for distillers to use SO2? (2)

Answer 12

1. High levels of sulfur compounds become unpleasant smelling when consentrates during distillation.
2. Adding sulfur before or during fermentation presents real dangers to the health and safety of staff.

Question 13

How might distillers minimize the risk of spoilage and oxidation? (2)

Answer 13

1. Ensuring a short time period between harvesting and the onset of alcoholic fermentation. The yeast is able to fend off microorganisms.
2. Blanketing the raw material in gas (typically CO2), as gas is denser than air and it would naturally cover the raw material, blocking out any oxygen.

Question 14

In order for a fruit to be commercially important, what criteria should it meet? (2)

Answer 14

Fruiting plant needs to:
1. Be domesticated
2. Provide a usable quantity of sugar-rich juice

Question 15

Which are the most widely used fruit species in alcohol production? (3)

Answer 15

Apples, pears and grapes.

Question 16

Explain the two stage process to releasing fruit juice.

Answer 16

1. Fruit is fed through crusher, releasing some of the juice.
2. Crushed fruit is pressed to release remaining juice.

Question 17

What is pomace?

Answer 17

Grape skins and stems left from winemaking.

Question 18

Which grapes are white wines commonly made of?

Answer 18

White grapes.

Question 19

What grapes are red wines made from?

Answer 19

Black grapes.

Question 20

Where does red wine get its dark color and much of its flavor from?

Answer 20

From the grapes’ skins which are included in the fermentation process, but then pressed to extract the remaining juice and discarded.

Question 21

How might be white grape pomace handled?

Answer 21

It may be delivered to a distillery where the distiller ferments the residual sugars in order to create alcohol.

Question 22

How might black grape pomace be handled?

Answer 22

Black grape pomace typically already contains some wine (alcohol), so distillation could take place immediately if it were delivered to a distillery.

Question 23

What type of sugar is found in the stems of the sugar cane plant?

Answer 23

Sucrose

Question 24

How is sugar cane processed?

Answer 24

The stems are broken open, shredded and crushed to extract sugar cane juice.

Question 25

What is bagasse?

Answer 25

Plant fibres left behind from the extraction of sugar cane juice.

Question 26

How can bagasse be used in the sugar refinery?

Answer 26

As fuel to supply power to the refinery.

Question 27

How is sugar cane juice treated before the refining process? (2)

Answer 27

Its is (1) pasteurized to kill any unwelcome bacteria and fungi.

And (2) clarified to remove impurities and suspended oils.

Question 28

What is the first step to creating sugar and molasses?

Answer 28

Creating cane syrup by evaporating water off of sugar cane juice.

Question 29

What equipment is used in processing cane syrup? And how does it operate?

Answer 29

Pan boiler. If operates under partial vaccuum conditions.

Question 30

How are A-sugar and A-molasses produced? (3 steps)

Answer 30

1. Cane syrup is mixed with sugar seed crystals.
2. The mixture is heated in the pan boiler. As water evaporates off some of the sucrose can no longer stay in solution and starts to build around the seed crystals.
3. The mix of liquid and sugar crystals pass through a centrifuge, separating the sugar crystals from the syrupy liquid.

Question 31

When, during the sugar production process is the highest quantity of sugar extracted?

Answer 31

When A-sugar is produced.

Question 32

Describe the quality of A-sugar?

Answer 32

Highest quality with the least impurities.

Question 33

How are B-sugar and B-molasses produced?

Answer 33

1. A-molasses are mixed with more sugar seed crystals and moved to the second pan boiler, then the mixture is boiled.
2. Sugars are separated from molasses using a centrifuge.

Question 34

Describe the quality of B-molasses and B-sugars.

Answer 34

There’s a higher quantity of impurities. B-molasses are thicker and darker in color.

Question 35

How are C-sugars and C-molasses produced?

Answer 35

1. B-molasses are mixed with more sugar seed crystals and moved to the third pan boiler, where the mixture is boiled.
2. The mixture is centrifuged to separate the two products.

Question 36

How is C-sugar used in the refinery?

Answer 36

It’s used to form the seed crystals for future batches.

Question 37

How are C-molasses used in the refinery?

Answer 37

They are usually a by-product as they have a very high level of impurities. C-molasses are very dark, viscous and hard to work with.

Question 38

C-molasses are also known as…

Answer 38

Blackstrap molasses

Question 39

A- and B- sugars are also known as..

Answer 39

Brown sugar

Question 40

What are are the flavors/aromas of brown sugar? (2)

Answer 40

Toffee and Caramel.

Question 41

How is white sugar made?

Answer 41

By further refining brown sugar.