So the original gravity is off the charts and we are unsure how to measure it. The intended original gravity was 1.090. It looks like if the hydrometer continued to go down it would have been 1.180. How do we measure this thing.
I seriously doubt you hit 20 %, due to the extreme measures it takes to get yeast of any sort to go through that type of fermentation. Most likely end up with a syrupy sweet mess. Good luck though
Is there a high gravity yeast I can add in a couple days to help? The recipe is in a book? I don't have it with me so I'll let you know later, but we followed it perfectly... Of so we thought.
Ignoring the fact that this should be in a forum other than "Announcements & Feedback", I would love to see the recipe.
You may find some Belgian yeast that could be tolerant to 17%, and white labs sells a yeast that they claim is good to 25% (WLP099), but you will have to have a lot of aeration and pitch a huge starter.
To get that far off, you would either have to have the most insane efficiency (100%+), or you are using extract (or large sugar additions, etc.) and didn't get it all mixed in properly. I'm going with human error.