Impy stout, mash temp question

[HollisBT]

I am about to brew a big imperial stout this afternoon, with an anticipated OG of 1.100. I am torn on what temp to mash at though... My logic tells me to mash higher, to build up some dextrins and guarantee a nice mouth feel, but my knowledge of yeast tells me that no matter what I am still guaranteed to have a higher FG when it is all said and done and I should mash low to help the yeast do their job...

Can anyone offer me any input on this? Should I go to the higher side, at about 157? Or keep it nice and low at about 150...

 

[masscarriers]

If you experience a higher FG than anticipated, it's probably more a question of yeast viability / pitching size. Obviously mashing lower will generate a more fermentable wort but also less mouthfeel, which you want. If you want to address the true problem, look up your fermentation conditions first (maybe ferm temp is too low, oxygenation is poor, yeast cells are stressed or underpitched...).