Primary has a sour smell

We recently brewed a Robust Porter, which came out great, and I decided to use second runnings to use for starters for our bigger batches. I got 5 gallons of second runnings and boiled for 15 minutes. I then cooled it, put an airlock with starsan, brought it home, and put

it in my Keezer. 3 weeks later I found time to do a real boil and get the gravity up to 1040. I boiled for 90 minutes and added hops. I then decided to make these experiments and added 1056 in 1 gallon, Brett L, in another gallon, and a mystery yeast I grabbed from a craft beer bottle in a 3rd gallon. Fermentation went great in 2 of them and the Brett L started fermenting a few days ago. All looks good with no noticeable infection but when I went to take a reading there was a sour smell. I checked all 3 gallons and they all have the same smell. My first thought was that lacto began to sour the wort during that 3 week period it was sitting in my Keezer. Wouldn't lacto have been killed by the 15 minute boil? The wort smelled awesome before my 90 minute boil. All jugs fermented at 63 degree ambient. Anyone know what this might be. It doesn't really smell bad. It almost smells like what I was going for.

No takers on this? Should I be posting this to one of the other forums?

I'm interested to see what other have to say, 15 minutes on the second runnings should have killed most of everything but that would have been your point of infection, if there was one. It could very well be a bi-product of your yeasts that is giving it the stank. If I were you I would let it ferment for a bit and give it a taste in the a few days, that'll be your real indicator if it was gassing off, or really infected.

it could have started souring before the boil. being kept cool could've kept the smell down. you might be smelling the sour now because it's warmer. foster's adds a little soured wort to their beer, and it works for them

That was my original thinking. I wonder if Lacto was picked up from the grain bed and wasn't killed in the boil. This would cause it to sour for the 3 weeks but my other thought is that a 15 minute boil should have killed the Lacto. They all smell a little bit different after fermentation but that sour smell is prevalent in all of them. I doesn't even really smell that bad if you like sours, which I do. It will be 2 weeks on Sunday so I will take gravity readings and taste them. I will let you know how they taste. I will probably let all of them sit for 4-6 months regardless but we will see. I am still open to thoughts on this. It has confused me!!