I have done 2 BIAB batches and hit 86 % doing this: heat water to 165, add grains let sit 30 mins , reheat to 165 while stirring, sit 30mins , remove bag and dunk and swirl in another pot with 170 water for 10 mins. Poured all water back thru grain bag to filter. These were 3 gallon batches . Bought a igloo mash tun and have done 2 batches and did a pre heat inside cooler to help with temp accuracy, added grains @ 167 water , sat 30 mins stirred, sat 30 then drained wort, added 212 water and let sit 10 mins then drained and fly sparked to fill brew pot. Checked pre boil gravity and was at 1.030og was supposed to be 1.057 for a 5 gallon batch. Last batch recipe was : 6 #2 row, 2#pilsner 2# minute rice dust added rice to mlt did not re hydrate. Please help