The manufacturer goes to great lengths to make sure their product will last as long as possible granted, but it will eventually go bad in the sealed package from the same "nasties" you speak of. I'm not trying to be a "bearer of bad news", just trying to help a new brewer learn from their mistakes the same way we all did. If there is ANY chance something other than the yeast strain you want to ferment your beer is present in the ingredients you absolutely NEED to boil the said ingredients to make sure it is sterile. Things like this is what makes some brewers think to themselves "why is my beer infected, I added only what those guys online said was ok?". Rule of thumb of brewing, anything that touches your chilled wort has to be sterilized!!!!!! Is your beer going to be ok, probably. Just make a better effort next time to keep everything sanitary, you WILL make better beer because of it.