Detecting an infection after bottling

Hi all,

This isn't the standard "Oh god my beer!" thread, but more a general question about determining whether or not a beer is truly infected and destined for the toilet.

Typically after the wort is moved the fermentor and the yeast pitched I practice a rigid -HANDS OFF- policy until bottling day (usually 3-6 weeks), when I will move it from the primary into a bottling bucket then into bottles.

My recent concern is that I found out my sanitizing practices have been flawed. I have been improperly storing and reusing my star-san solution so it may not have been sanitizing at all. I did not notice any funky growths and no off-smells during the fermentation, though I was not monitoring the beers because I was not concerned at this point.

So here are my questions:

Are all infections visible? Can you have a hidden infection in a beer? What are some of the tell-tale signs of an infected batch so when I finally crack one of them open I will know what to look for? Can the be subtle or are all infections quite obvious when you taste it?

Well, if you have a gusher type infection in the bottle you probably won't taste it, but you'll know...trust me!

most infections leave you with sour tasting and smelling beer. some will smell just like vinegar (acetobacter infection from fruit flies I think).

and most beer turns out fine.