Originally Posted by brewt00l
The truth is that hops do not provide a supportive environment for most types of bacteria. On top of that, if the hops are added to the primary fermenter after the start of fermentation, any bacteria on them will have a difficult time competing with the vigorously active yeast in the wort. If the hops are added to the secondary fermenter then the alcohol content and the low pH of the beer will suppress bacterial growth. Keeping this in mind, its safe to say that bacterial contaminations caused by dry hopping are extremely rare and not worth worrying over. http://byo.com/departments/1105.html
Here's an article on dry vs hopback:http://www.byo.com/mrwizard/890.html
Thanks for the articles! I knew about the protective effect of pH and alcohol on already fermented beer, but common sense states that all plants have indigeonous bacteria on them, including many soil microbes. In solution, I'm sure the alpha acids are quite antiseptic, but while they are still in the lupulin glands they do not have this effect. I wanted to clip some time off my turnaround on IPA's because the dryhopping takes up about 2 weeks.
Incidentally, the "scrubbing" action seems to be heresay. I mean, we use bittering hops in the boil, and the yeast don't even begin to scrub that out...