Wort. Sweet liquid "tea" made from steeping malted grain in hot water. It looks like beer, but it is not yet beer.
Some say that brewers make wort, not beer. Its the yeast that do the real work, converting sugars in the wort into alcohol and carbon dioxide, and adding all sorts of flavors in the process.
I relate this to teaching. As an educator, I know that I can't give knowledge to students. Instead, I create an environment and experiences through which students construct their own learning.
Same thing with brewing. Brewers create an ideal environment in which yeast do the actual work of making beer. And different yeast (like students) need different conditions to thrive.
At Le Brewery, the way Steve talks about his yeast, you'd think she was a member of the family! An old revered grandmother. Yeast, with her life-giving properties, is decidedly feminine.
Knowing your yeast, and caring well for her, is a major part of the art and science of brewing.
Only she can turn humble wort into something much more.