Utilize the input text as a context reference, choose the right relationship between 'brewing' and 'beer' from the options.
Options: product/material produced, legal form, operator, business division

Founder Christian Ettinger was a business student at the University of Oregon when he first began brewing beer in the early 1990s and remembers when craft or specialty beer consisted of the Killian’s Irish Red, Coors Winterfest and Henry Weinhard’s Dark, Red or Ale.
product/material produced