Heres the story I recently switched to all grain and my first four batches have had very high finished gravities. None of the batches have been too high on the OG but FG's have all been around 1.026, I have tried a second hydrometer to confirm this and it too reads high. The first two were aerated by shaking and had no starters. The third batch was pitched with yeast washed from the second batch (WP 001) and the fourth was shot with pure o2 for 1 min, no starter WP 001. The last two have been temp controlled at a constant 72 degrees. Fermentation starts off great and then 3-5 days later dies off, I usually give it a day or two more then check the gravity before transferring to the secondary. In the secondary I may get lucky and see it drop a few points but thats it. I'm scratching my head as too why they are finishing so high, only things I can come up with is I need a starter, but they have been relatively low OG's and batch two had at least a cup of slurry pitched. Or my thermometer is out of calibration when I'm mashing and mashing at too high of a temp, I shoot for 152. Any ideas??? If the thermometer were off could it cause that great of a difference in the FG.