Lesson 5 - Types of microorganisms SAQ
This lesson enables you to test yourself on the material covered in the Types of Microorganisms lesson, and determine to what level you have attained the outcomes.
Self-Assessment Questions
1. **Wild ales refer to mixed fermentation beers that are fermented with microorganisms other than brewing yeast. If you were to brew a wild ale, which microorganisms would you consider using and why?
2. **Answer BOTH parts of this question:
a) Give examples of Gram-positive beer spoiler bacteria and describe their impacts on beer quality.
b) Explain the systems they have developed to grow in hopped wort.
3. **Answer BOTH parts of this question:
a) Explain why Obesumbacterium proteus (Hafnia protea) is able to survive and eventually proliferate in traditional English ales.
b) Why is their presence a concern as a contaminant in brewing?
4. **Critically discuss the following statement: ‘Acetic acid bacteria (AAB) are no longer a major spoilage concern to brewers; a new risk is from Pectinatus and Megasphaera’.
5. **Discuss the classification and effects of yeasts that are described as wild yeast contaminants in a lager fermentation.