I’m on day 5 of fermenting a pumpkin ale. OG 1.065 with 2 pounds of canned organic pumpkin and an amber ale recipe. I pitched a 1.5L starter of WLP001 into wort cooled to 63F. Over the course of 4 days i gradually raised the temp to 70F. On day 4 after reaching 70F, I suddenly had a massive amount of blow-off that clogged the airlock and covered the lid of my brew bucket. I’ve used 001 many times before and have never seen this type of activity. Could it be the pumpkin that is causing the increased activity? The beer also has an incredible amount of kraisen this far into fermentatation when I would normally expect the head to fall. It smells of normal 001 yeast, and my sanitation practices haven’t given me any cause for concern before. Is this normal? Should I just RDWHAHB? I know the answer, but just curious if anyone has seen this extra activity before?
I’m sure you are fine. My guess is a slightly lower than optimal pitch rate, coupled with the increase in temp, created a crescendo of sorts that caused the yeast to go to town.
I’ve had batches I thought were safe to switch from blow off to airlock only to come home from work to a mess in the ferm freezer. Wy2565 in particular tends to catch a second wind 5-6 days in for me.
Probably smells like thanksgiving in your house:)
I have had this happen on the 3 pumpkin ales i have made. My assumption is that the yeast are working there butt off to break down the brewing sugars from the pumpkin puree itself. Depending on when you added your puree, boil, mash or primary you may also have a lot of pumpkin material that is binding with the rest of the trub and what not to cause this massive krausen. i have found i need to keep my temp low till 75% complete to keep the fusels at bay. bet it will be tasty
My thought is that the organic material from the pumpkin is giving a big boost to the “head retention” of your krausen.
At what point did you add the pumpkin? The pumpkin I put in my recipe definitely raised the gravity of my beer. Now it’s a stronger pumpkin ale 
I mashed the pumpkin and stirred it in from the beginning of the mash. I don’t have my notes in front of me, but I think I did a protein rest at 133F for 20 minutes (it may have been 122F). And raised the temp to 154F for around 45-50 minutes until conversion was complete.
Just curious but did you actually account for the pumpkins sugar in your recipe? I think I may have made the same mistake as you. I counted up and estimated my original gravity based off the grains. But I didn’t account for the content of the sugar in the pumpkin as well. I ended up with an original gravity far exceeding what I had estimated for in my recipe
I did some digging around on this the other day and was unable to find anything that indicated pumpkin adds more than about 8 points to a batch of beer. how much did you use and in what way?
I used 2 pounds of pumpkin, mashed, and figured I’d get an additional 2 gravity points in a 5 gallon batch. My OG was only off by .001 (low). I’m not sure how gravity effects the amount of blow-off I got from the yeast.
I used 2 lbs of canned pumpkin that was roasted and then mashed into my recipe. I’ll have to look it up tonight but it did add some to my OG. Going through other forums and looking, it just seems like it’s hit/miss on how much pumpkin you actually convert to sugar.
Anyways, I would think your excessive blowoff was due in some part to the pumpkin. Or maybe you just had really healthy yeast. But regardless, is a large blowoff really a bad thing? 
For me it’s always a good sign of things to come.
I got my brew into a keg last weekend. After transferring over, I noticed quite a bit of orange gunk mixed in with the yeast. I’m guessing that some of the pumpkin bits carried over from the mash. I’m going to guess that contributed to the vigorous fermentation somehow. I’m not overly concerned about any of this, but I had just never seen that much activity before from WLP001. It smells and tastes pretty good pre-carbonation. I fined with some gelatin so I’ll have to wait until this weekend to see how the final product turns out.