It really is harder than most noobs think to infect their beer. In fact 90% of the "is my beer infected" threads are really just "I have noob nerves, hold my hand" threads and the beer isn't infected at all.
It's really a silly question to ask, or worry about. And you know, if your beer is infected? So what...it may even be tasty...hence all the folks who like sour beers....they're INTENTIONALLY infected, and often with the same micro organism that "accidently" get into our beers.
The worse one is really acetobactor...and then you end up with malt vinegar...which you might even be able to pack in cute bottles, or sell. You can't sell beer, but there's no law you can't sell malt vinegar.
Besides often what new brewers think is infected, is really just that their beer is green; they're drinking it too young.
And if it is, meh, it happens to everyone at some point in their life...even commercial breweries, did you ever see the brewmaster's series on tv with Sam Caligione and Dogfish Head? They had a couple multi million dollar dumpers on that show...they gritted their teeth and moved on.
Read this thread,
Has anyone ever messed up a batch?? and relax....Infections are things new brewers tend to obsess about, while the rest of us know it happens, and just shrug it off and move on.
If your beer is infected...you taste it, if it still decent you drink it,
nothing that can harm you can exist in beer infected beer cannot hurt you. If it doesn't taste good you dump it..So what?
*shrug*
But first MAKE sure that the reason that it tastes off isn't mere because you're drinking it too young.