Where am I off here on my PBG, OG, readings

[olotti]

I’m not new to brewing been doing this long enough on my same system and never seen this discrepancy happen ever So wanted some thoughts. I mashed and sparged and got my pbv of 7.75 gal. Mixed it up and took a sample and let that cool to 73 deg, took a reading with my hydrometer and it read 1.06–1.062 hard to tell with bubbles so let’s say 1.061, spot on to my beersmith calculations. I boiled down to 6.25 gal, chilled to 175 deg added my whirlpool or hopstand hops till temp hit 135. Chilled to 95 deg since I’m using hornidal kviek I like to chill to that temp since I’ll also lose a little heat during transfer via siphon. while filling csrboy with siphon I pulled a sample. It read 1.072 but my projected gravity per beersmith with those final volumes which are always my target volumes of 6.25 end of boil 5.75 into fermenter which I hit was supposed to be 1.083. So am I missing something. how Do I hit my pbg, hit my volumes into boil and fermenter and end up so low. What am I missing.
*I edit the post to show my beer smith recipe in the post below. * just to show the volumes I put in and that the og is still coming out to 1.081. So somethings not right.

 

[mcmeador]

Sounds like maybe you’re using your “into the fermenter” volume as your “post-boil” volume for the calculations? In other words, you’re telling Beersmith you boiled off 2 gallons rather than the 1.5 gallons you actually boiled off. Playing around with a calculator on Brewer’s Friend, it looks like that would cause the discrepancy you’re seeing.

 

[PT Ray]

Sounds like maybe you’re using your “into the fermenter” volume as your “post-boil” volume....

Precisely! Good catch.

 

[olotti]

Sounds like maybe you’re using your “into the fermenter” volume as your “post-boil” volume for the calculations? In other words, you’re telling Beersmith you boiled off 2 gallons rather than the 1.5 gallons you actually boiled off. Playing around with a calculator on Brewer’s Friend, it looks like that would cause the discrepancy you’re seeing.

Good point however it’s never happened before and I’ve been using beersmith with the same setup for 7yrs. I just brewed 2 weeks ago using the same numbers, calculations and volumes and hit them all. So idk. And I just went into beersmith to check everything and it’s what I’d normally expect. Est pbv 7.75 gal , boil off 1.63 gal, pbv 6.13 gal I may have been at 6.25 gal maybe 6.5 even but that shouldn’t be a 12pt diff in OG.

 

[VikeMan]

7.75 gallons @ 1.060 = 465 "points"
Boiled down to 6.25 gallons, you should get 465 / 6.25 = 74 points per gallon, or 1.074, not 1.083.

How much volume you get into the fermenter after that isn't really relevant.

 

[olotti]

7.75 gallons @ 1.060 = 465 "points"
Boiled down to 6.25 gallons, you should get 465 / 6.25 = 74 points per gallon, or 1.074, not 1.083.

How much volume you get into the fermenter after that isn't really relevant.

Ok then I wasn’t to far off. Something must be off in my beersmith program then. I’ll have to go back and check it.