Yeast And Making Beer

Question 1

Yeast is a very useful _____________

Answer 1

Microorganism

Question 2

We use ______________ respiring yeast to make _________

Answer 2

Anaerobically

Beer

Question 3

Using yeast to brew beer:
1. Firstly you need to get the __________ out of the grain:
Beer is made from grain - usually _________. The __________ grains are allowed to germinate for a few days, during which the _________ in the grains is broken down into sugar by ___________. Then the grains are dried in a ________. This is called ___________.
The malted grain is mashed up and _________ is added to produced a sugary solution with lots of bits in it. This is then _________ to remove the bits. ________ are added to the mixture to give the beer its bitter flavour.

Answer 3

Sugar
Barley
Barley
Starch
Enzymes
Kiln
Malting
Water
Sieved
Hops

Question 4

Using yeast to brew beer:
2. Yeast is added and the mixture is _____________ (warmed up). The yeast ferments the sugar into __________ . The fermenting vessels are designed to stop unwanted microorganisms and _____ getting in.
The rising concentration of __________ (ethanol) in the fermentation mixture due to ___________ respiration eventually starts to kill the yeast. As the yeast dies, fermentation ________ _______.
Different species of yeast can tolerate different levels of alcohol. Some species can be used to make strong beer with a ________ concentration of alcohol

Answer 4

Incubated
Alcohol
Air
Alcohol
Anaerobic
Slows down
High

Question 5

Using yeast to brew beer:
3. The beer is drawn off through a ______. Sometimes chemicals called ____________ agents are added to remove particles and make it clearer

Answer 5

Tap

Clarifying

Question 6

Using yeast to make beer:

4. The beer is then ______________ - heated to kill any yeast left in the beer and completely stop ______________

Answer 6

Pasteurised

Fermentation

Question 7

Beer tastes better if it’s ______________ and aged in the right conditions. But big breweries _______________ it anyway because there’s a risk that _________________ beer will spoil if it’s not stored in the right conditions after it’s sold. Finally the beer is casked ready for sale

Answer 7

Unpasteurised
Pasteurise
Unpasteurised

Question 8

Unpasteurised
Pasteurise
Unpasteurised

Answer 8

Conditions

Question 9

You can do experiments to investigate how the rate of _______ production by yeast changes under different conditions

Answer 9

CO2

Question 10

w to measure the effect of changing temperature on respiration rate in yeast:
1. Mix together some _________, ________ and distilled ______. Then add the mixture to a _______ tube.
2. Attach a ________ with a tube leading to a second test tube of _________.
3. Place the tube containing the yeast mixture in a water ________ at a certain temperature
4. Leave the tube to warm up a bit and then count how many __________ are produced in a period of time. Use this to calculate the _______ of CO2 production (which gives an indication of respiration rate)
5. Repeat the experiment with the water bath set at different _______________.
Respiration is controlled by enzymes - so as temperature increases, so should the rate of respiration (as they get towards their ___________ temperature

Answer 10

Yeast, water and distilled water
Test
Bung
Water
Bath
Bubbles
Rate
Temperatures
Optimum

Question 11

How to measure the effect of changing sugar on respiration rate in yeast:

Answer 11

Same as temperature but change the sugar levels rather than the temperature of the water bath