so I recently made a 5 gallon all grain brew (Grandma's Secret Stash) and it calls for adding raising to the end of the boil. I did a little tweaking to the recipe, but nothing major... mostly just adding some molasses, using a slightly more "stout" type of hops, that's about it. The boil was a little more violent than I wanted, but no scorching seemed to occur. However, I do believe some of the raisins may have made it into the primary fermenter.
That being said, after a few weeks of fermentation, I transferred to the secondary. I made sure any and all raisins did not make it into the secondary. I took my gravity measurements, tasted my gravity sample and it was very good. The smell seemed like a rum raisin flavoring on top of a stout, the taste seemed to agree.
However, after letting it sit in the primary for about 11 days, I was supposed to add some vanilla beans and cinnamon. When I took the top off of my carboy, I noticed a sour smell coming from the beer inside. I took all the precautions I could have in terms of sanitation, so I don't know where any bacteria could have come from. At first, I thought something could be up in terms of the raisins. They are, in fact, just grapes, and maybe some sort of wine-like fermenting had gone on. Then, I did some research online, and many people seemed to believe fermentation sometimes just smells bad even if the beer is good. I won't be bottling for another week, and then it is about 2-3 weeks after that before I drink it.
This means I may drive myself crazy waiting for 3-4 weeks, worried that my beer has been contaminated. Like I said, I tried really hard to sanitize everything, and the smell was not present during the transfer from primary to secondary. Does anyone have any thoughts as to why this is happening? Hopefully this isn't all too unheard of, and maybe you guys can put my mind at ease...