I've had a good run with all grain batches.... never had a stuck sparge, stuck fermentation, or any contamination. Now my streak of 14 batches is broken sadly.
I normally use pie pumpkin chunks in a grain bag, which worked very well before. In fact, my primary fermentation is usually quite vigorous and I have to change my blowoff jug water every day for the first few days.
I did some research on pumpkin beer before creating the last batch and decided to try canned pumpkin instead. I caramelized as usual in the oven after spreading on cookie sheets. The info I found on this site (I think it was this site) said that some people put the caramelized pumpkin into the mash instead of the boil. I did this and proceeded normally.
However, the fermentation was very weak and only lasted a couple of days. I was expecting around 8% ABV, but only ended up with 3%....
I transferred to secondary and added my bourbon-soaked oak spirals anyway, thinking I would salvage this batch somehow. After six weeks or so, I decided to add another batch of identical yeast in case the old yeast were tired or dormant. This did not produce any activity, leading me to believe that there just isn't any sugar left to utilize.
Did using caramelized canned pumpkin in the mash kill my sugar extraction? This is my only conclusion based on my limited knowledge.
If this is my problem, can I improve the beer by adding some boiled DME to bring up the gravity again? I'm not concerned about altering the flavor at this point, I just want to bottle this stuff already!