The most important (and common) advice that new brewers get is that sanitation is paramount. This makes perfect sense because many of the common off flavors stem from contamination from wild yeast or bacteria. Most of us take this message to heart and dutifully sanitize the obvious stuff such as the fermentor and hoses (everything on the cold side of the brewing process should be sanitized). Much of the time, that works well enough, but sometimes, something goes awry and a batch develops a clearly unintentional funk. An off beer may convince you that you should be more diligent, which is a good idea, but there are three key areas that will lead to cleaner, tastier beer.
Sanitation vs. Cleaning
Sanitation and cleaning are easily confused, but both are important to nurturing your yeast. You want to make sure that every surface that touches your beer, from the boil kettle to the glass, is free of microbial wildlife. Without cleaning everything first, though, you’re missing the point. Dried gunk stuck to your carboy provides an irregular surface that the sanitizer can’t easily reach. Beasties can lurk in crevasses and wait things out. Later, while your beer is fermenting, they can reproduce and come into contact.
You need to remove dirt and other deposits from your equipment so the bacteria have nowhere to hide and your sanitizer can do its job. That’s why you should follow a two-step process of cleaning your equipment first, then sanitizing. Cleansers, such as Powdered Brewery Wash (PBW) or OxiClean Free, will strip away dirt, dried beer and wort, and other residue. After a quick rinse, you can bring on a sanitizer such as Star-San or Iodophor to finish the job.