I am finding my mash efficiency is not what it should be. I have a nicely insulated mash tun, and spend a lot of effort maintaining a perfectly constant temperature through the mash (I mash-in my ale at about 69deg C and get less than 1 degree temperature drop over the 90 minute mash). I have read about people stirring their mash. I leave mine totally alone after the initial stir to wet the grain. What are the feelings about stirring (ie opening tun and losing temperature profile, but perhaps getting better efficiency) ? Are there any considerations around a stuck mash which might happen from interfering with the mash?