The element was covered with black carbon deposits the first time, when I was trying to do a 90 min boil. Hops were in a bag that time.
2nd time I didn't notice the scorched taste until afterward---I do no-chill, and had about a quart in the fridge for a starter, and noticed the starter wort had a burnt smell.
Not really sure how this is happening, as I've had 10+ successful all grain brews with this keggle.
I've cleaned off the element, and will be trying again tonight.
This time the pumpkin is going in the brewbucket, with the hot wort piped onto it at the end of the boil. This time of year it takes about 24 hours to cool down to pitching temp.