I want to know the answer to the following question:
What causes fermentation during the brewing process when making a beer?
All the background I'm provided with is that "The basic ingredients of beer are water; a starch source, such as malted barley, able to be saccharified (converted to sugars) then fermented (converted into ethanol and carbon dioxide); a brewer's yeast to produce the fermentation; and a flavouring such as hops.". Is that enough to answer the question?
Answer: yes