I've run into an issue in back to back brews where I've undershot my mash temp when brewing beers with a larger grain bill(1.070 - 1.088).
The first time I followed mashed in 2 degrees higher than the infusion guidelines on Beersmith called for (They said 160F I mashed in at 162F), on a 1.071 18lb IPA. I ended up undershooting my 149 target by and hitting 147.6.
Today I'm doing Denny's vanilla bourbon porter (1.088 22lb grainbill), which calls for a 155F sacc rest. Beersmith said to mash in at 165.8 and brewers friend suggested 167F. I mashed in at 168 and by the time I was done mixing the grain and making sure there was no dough balls (maybe 2 min from adding grain to done) I was at 150F, 5 full degrees short.
I mash in a 10gal round cooler and I believe beersmith calculates volumes based on 1.33qt/lb. Is this normal? Am I missing a process gotcha?