I don’t want to understate the importance of sanitation. If you’re an all-grain brewer like myself, every batch doesn’t just represent 6 gallons of beer (or however much you make at a time), but it also represents at least 6 hours of time.
I think of sanitation as being in two categories: pre-boil and post-boil.
Equipment that is used pre-boil (and during the boil) doesn’t need to be thoroughly sanitised; equipment that is used post-boil does.
If I need to stir my finishing hops and haven’t sanitised the big spoon that I use, I use it as is unless it’s obviously dirty. But that same spoon gets cleaned and thoroughly sanitised before I use it to aerate.
Sometimes I sanitise my pre-boil equipment, but mostly I try to make sure it stays clean and let the boil handle any small left-overs.
Post-boil is a different story. If you are like myself and like to minimise work, then focus on post-boil sanitation because that is where some flock of bacteria is going to mess up your hard work.
For more on sanitation, check out this month’s homebrew sanitation pracitices Fermentation Friday.