The Science of Fermentation: Reading Answers & Explanations
IELTS Reading practice test · 14 questionsAcademicmedium
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About this passage
The passage opens: “Fermentation is one of the oldest technologies in human history, though for most of that history no one understood how it worked. Long before anyone had heard of microorganisms, people were making bread rise, turning grape juice into wine and preserving vegetables in brine.”
- Passage length: about 757 words
- Questions: 14
- Question types: True / False / Not Given, Multiple Choice, Short Answer
“The Science of Fermentation” is an original IELTS-style practice passage written by IELTS-Bank. It is not taken from an official IELTS or Cambridge test, so these answers only apply to our version.
Answer key at a glance
The Science of Fermentation answers with explanations
Questions 1–6: True / False / Not Given
Do the following statements agree with the information given in the passage? Write TRUE if the statement agrees, FALSE if it contradicts, or NOT GIVEN if there is no information.
- 1
People made fermented foods before they understood the role of microorganisms.
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Answer: TRUE
Why: This sentence confirms the statement, so the answer is TRUE.
Evidence · Paragraph 1 “Long before anyone had heard of microorganisms, people were making bread rise, turning grape juice into wine and preserving vegetables in brine.”
- 2
Fermentation by yeast requires a plentiful supply of oxygen.
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Answer: FALSE
Why: This sentence directly contradicts the statement, so the answer is FALSE.
Evidence · Paragraph 2 “…fermentation is the breaking down of sugars by microorganisms in the absence of oxygen, or with very little of it.”
- 3
In bread making, the carbon dioxide gas is more important than the alcohol.
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Answer: TRUE
Why: This sentence confirms the statement, so the answer is TRUE.
Evidence · Paragraph 2 “In bread making it is the gas that matters, because the bubbles of carbon dioxide become trapped in the stretchy network of the dough and cause it to swell.”
- 4
Rye bread is generally lighter than bread made from wheat.
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Answer: FALSE
Why: This sentence directly contradicts the statement, so the answer is FALSE.
Evidence · Paragraph 3 “…breads made from flours low in gluten, such as rye, tend to be heavier”
- 5
Sourdough bread is more expensive to buy than bread made with commercial yeast.
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Answer: NOT GIVEN
Why: The statement claims sourdough bread is more expensive, but the passage does not address the cost of sourdough bread compared to bread made with commercial yeast.
Closest related text · Paragraph 5 “By making the dough more acidic, they help preserve the bread and slow the growth of unwanted moulds, so a sourdough loaf often keeps longer than one made with commercial yeast alone.”
- 6
Cooling dough in a refrigerator can help its flavour develop.
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Answer: TRUE
Why: This sentence confirms the statement, so the answer is TRUE.
Evidence · Paragraph 6 “Many bakers deliberately slow the process down by placing dough in a refrigerator overnight, a technique that allows flavour to develop while the rise is gentle and controlled.”
Question 7: Multiple Choice
Choose the correct letter, A, B, C or D.
- A. Water and salt
- B. Alcohol and carbon dioxide gas
- C. Gluten and starch
- D. Acid and heat
- 7
According to the passage, what two products does yeast make when it consumes sugar without enough oxygen?
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Answer: B — Alcohol and carbon dioxide gas
Why: This is the part of the passage that supports B — Alcohol and carbon dioxide gas.
Evidence · Paragraph 2 “…it produces two main products: alcohol and carbon dioxide gas.”
Question 8: Multiple Choice
Choose the correct letter, A, B, C or D.
- A. It provides food for the yeast.
- B. It gives the dough its sour taste.
- C. It allows the dough to stretch around gas bubbles without tearing.
- D. It kills unwanted moulds in the bread.
- 8
What role does gluten play in bread dough?
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Answer: C — It allows the dough to stretch around gas bubbles without tearing.
Why: This is the part of the passage that supports C — It allows the dough to stretch around gas bubbles without tearing..
Evidence · Paragraph 3 “Gluten gives dough both strength and elasticity, allowing it to stretch around the expanding gas bubbles without tearing, rather like the skin of a balloon.”
Question 9: Multiple Choice
Choose the correct letter, A, B, C or D.
- A. The gas that makes the loaf rise
- B. The acids that give the tangy flavour
- C. The gluten network in the dough
- D. The alcohol that evaporates during baking
- 9
In a sourdough starter, what do the lactic acid bacteria mainly contribute?
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Answer: B — The acids that give the tangy flavour
Why: This is the part of the passage that supports B — The acids that give the tangy flavour.
Evidence · Paragraph 4 “…the bacteria produce acids that give sourdough its characteristic tangy flavour.”
Question 10: Multiple Choice
Choose the correct letter, A, B, C or D.
- A. It makes the bread rise more quickly.
- B. It causes the bread to spoil faster.
- C. It helps preserve the bread and slows the growth of moulds.
- D. It removes all the gluten from the flour.
- 10
What effect does the acidity produced by the bacteria have on the bread?
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Answer: C — It helps preserve the bread and slows the growth of moulds.
Why: This is the part of the passage that supports C — It helps preserve the bread and slows the growth of moulds..
Evidence · Paragraph 5 “By making the dough more acidic, they help preserve the bread and slow the growth of unwanted moulds, so a sourdough loaf often keeps longer than one made with commercial yeast alone.”
Questions 11–14: Short Answer
Answer the questions below. Choose NO MORE THAN THREE WORDS from the passage for each answer.
- 11
What type of single-celled fungi are especially important in baking and brewing?(max 2 words)
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Answer: yeasts (also accepted: yeast)
Why: The answer “yeasts” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 2-word limit.
Evidence · Paragraph 2 “Yeasts, which are single-celled fungi, are especially important in baking and brewing.”
- 12
What network of proteins gives bread dough its strength and elasticity?(max 2 words)
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Answer: gluten
Why: The answer “gluten” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 2-word limit.
Evidence · Paragraph 3 “The stretchy quality of bread dough comes from gluten, a network of proteins that forms when wheat flour is mixed with water”
- 13
What is the mixture of flour and water called that a baker keeps to cultivate wild yeasts?(max 3 words)
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Answer: a starter (also accepted: starter)
Why: The answer “a starter” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 3-word limit.
Evidence · Paragraph 4 “…a baker keeps a mixture of flour and water known as a starter”
- 14
Along with temperature, what is the baker's main tool for controlling fermentation?(max 3 words)
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Answer: time (also accepted: temperature and time)
Why: The answer “time” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 3-word limit.
Evidence · Paragraph 6 “Temperature and time are the baker's main tools for controlling fermentation.”
Estimated band score for this test
Your raw score out of 14 scaled to the 40-question IELTS Reading (Academic) conversion table. This is the same estimate the practice page shows after you submit. A single passage is a small sample, so treat it as a guide.
| Correct answers | Estimated band |
|---|---|
| 14 / 14 | 9.0 |
| 13 / 14 | 8.5 |
| 12 / 14 | 7.5 |
| 11 / 14 | 7.0 |
| 10 / 14 | 6.5 |
| 8–9 / 14 | 6.0 |
| 7 / 14 | 5.5 |
| 6 / 14 | 5.0 |
| 5 / 14 | 4.5 |
| 4 / 14 | 4.0 |
| 3 / 14 | 3.5 |
| 2 / 14 | 3.0 |
| 1 / 14 | 2.0 |
| 0 / 14 | 0.0 |
Full-test score? Use the IELTS band calculator.
Tips for the question types in this test
True / False / Not Given
- Read the statement first and underline the key idea, especially any qualifiers like "all", "only", "never", "always", "more than" or dates and numbers.
- Because the questions follow the order of the passage, scan for the paragraph that deals with the same topic rather than re-reading everything.
Common trap: Confusing "False" with "Not Given": choose False only when the passage actively contradicts the statement; if the passage is silent, it is Not Given.
Full True / False / Not Given strategyMultiple Choice
- Read the question stem carefully before the options so you know exactly what is being asked.
- Because multiple-choice questions follow passage order, locate the relevant section and read it in full — the answer usually depends on more than one sentence.
Common trap: Distractors that use exact words from the passage but distort the meaning.
Full Multiple Choice strategyShort Answer
- Read the instructions and note the exact word limit; going over it means zero marks even if the meaning is right.
- Turn each question into a set of keywords and predict what kind of answer it needs (a person, a date, a place, a noun).
Common trap: Exceeding the word limit (writing four words when only three are allowed).
Full Short Answer strategyPractise “The Science of Fermentation” under exam conditions
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