So, a little under a week ago, I brewed a goodly sized stout (1.069 OG) and when I mashed it I ended up missing my mash temp by about 4 degrees. (I was aiming for 158 and ended up with about 162-163.) I kept stirring with the lid of my cooler open to get the temperature down to 158, but this took about 10-15 minutes. I then mashed for a full 60 minutes and ended up hitting my gravity right on the nose.
I pitched a 1L starter of US-05 into it, and had a quick, active fermentation for 4 days (at about 62-66 degree range), and now the airlock is not moving anymore. This is when I usually start taking my gravity readings, and today I took one but it's only down to 1.030, but I'm expecting to get down to about 1.019.
Did mashing at such a high temperature "break" the extraction and I'm down as far as it will go? Seems strange that it did since I hit my numbers...
My plan is to RDWHAHB and let it sit for another week or two, but I'm just curious as to what might be going on here.