BIAB gravity question

I use Beersmith and BrunWater.  Brunwater gave values for water additions and both programs are amazing.  I did a Belgian Pale Ale and used .80 gal mash water and 1.10 gal sparge water.  This was a one gallon batch, still in secondary as I type this.  Beersmith said I’d be at about 1.036 post mash gravity, I was at 1.039. I can accept that.  Post boil volume was to be at about 54 but I was at 67.  My post boil volume was just slightly less than one gallon.  I used a larger “spaghetti pot”, larger than I needed.  I had to add water to adjust gravity to expected 54.  Could this higher gravity be from a “wider” pot and more evaporation or I “squeezed” the grain too hard before sparging?  Everything works out OK otherwise. After boil, I ended up, after a funnel/sieve, with about .80 gallons. My volumes seem weird?? Every batch I brew, extract or otherwise, I end up with less than the “brewed amount.”

Not really kettle geometry can play a factor but if your boil off is more than expected then top up to 1 gal.  With such a small batch the .2 gallons will probably put you at the expected OG.

Probably from higher evaporation rate than expected in the program.  Even at a stove top you are loosing more than 8% of starting volume.  It is adjustable in beer smith.

Thank you.  Yeah, the pot was pretty large with a very large surface area.  I’ll adjust up in Beersmith and see what gives.  Thank you.

I’m not sure how relevant this since I’m brewing 5.75 gal batches, but with BIAB  I lose about a gallon less liquid in the boil than most sources indicate for normal sparge.  I do really squeeze the grain bag hard though.

Keeping good records and adjusting as needed will get you closer to the brew you want.