I recently built a styrofoam fermentation chiller, similar to those found all over the internet. I have fermented three brews in it and all have finished with a really high final grav reading, at 1.020.
I used three different yeast strains, harvested starter of us-05, one harvested starter of wyeast 3068, and one dry yeast rehydrated of fermentis t-58. All three have finished at 1.020, after starting between 1.050-60. I haven't changed anything else with my process since then. I set the temp at 66-68 degrees.
Has anyone else encountered this issue? Or may it be something I am over looking.