Help me make sense of these no-sparge numbers

I brewed this version of OSH yesterday, and I'm not sure what's going on.

I mashed-in with almost all the volume (around 7 gals, had to leave some in the BK for recirculation). I left that in the MLT @ 160 for 30 minutes. Recirculated for 45 mins @ 160-161 degrees. Raised temperature to 168 for mashout and recirculated for 10 mins at mashout temps.

My preboil gravity was 1.038 (estimated at 1.040). I got about 6.9 gallons into the boiler, and hit my final volume dead-on. OG came in at 1.057 (estimated at 1.052). How can this happen? How can I get a 5 point increase in OG when I got a 2 point decrease in pre-boil? Is this due to setting brewhouse efficiency at 60%? Or is it a function of boil-off only?

Sort of a related question. Does/can Beersmith adjust grain bill for different efficiencies? I think I got it to do it one time, but cannot remember how I did it. Thanks.


--------------------------
Batch Size: 5.00 gal
Boil Size: 6.40 gal
Estimated OG: 1.052 SG
Estimated Color: 8.6 SRM
Estimated IBU: 41.8 IBU
Brewhouse Efficiency: 60.00 %
Boil Time: 60 Minutes
Ingredients:
------------
Amount Item Type % or IBU
1.00 lb Lyle's Golden Syrup (0.0 SRM) Extract 9.09 %
8.25 lb Pale Malt (2 Row) US (2.0 SRM) Grain 75.00 %
0.50 lb Caramel/Crystal Malt - 10L (10.0 SRM) Grain 4.55%
0.50 lb Caramel/Crystal Malt - 60L (60.0 SRM) Grain 4.55%
0.50 lb Victory Malt (25.0 SRM) Grain 4.55 %
1.00 oz Northern Brewer [8.10 %] (60 min) Hops 30.4IBU
0.50 oz Goldings, East Kent [4.50 %] (60 min) Hops 8.5 IBU
0.25 oz Goldings, East Kent [4.50 %] (15 min) Hops 2.1 IBU
0.25 oz Goldings, East Kent [4.50 %] (5 min) Hops 0.8 IBU
0.25 lb Dememera Sugar (2.0 SRM) Sugar 2.27 %
1 Pkgs Nottingham (Danstar #-) Yeast-Ale

Mash Schedule: Temperature Mash, 1 Step, Full Body
Total Grain Weight: 9.75 lb
----------------------------
Temperature Mash, 1 Step, Full Body
Step Time Name Description Step Temp
60 min Saccharification Add 32.00 qt of water at 164.9 F 160.0 F
10 min Mash Out Heat to 168.0 F over 10 min 168.0 F

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Anybody have any ideas?

I would bet it is your sugar and syrup additions. They can boost your OG over the Beersmith numbers.

Doh! Thanks for pointing that out. That makes too much sense. I forgot about those additions. I feel so stupid.......

The differences in SG probably have to do with discrepancies in your volumes. You say you hit your volumes perfectly, but volumes are hard to judge. I mean, if my volume is at the 5 gallon mark on my bucket, I say its five gallons. But I have never calibrated it, and even if it was 100% accurate, I can't eyeball it and tell whether I'm not 1-2% over or under.

That is going to affect your measured SG. Furthermore, there is an increase and decrease in volume of about 4% depending on the wort's temperature. So if you measure volume when its hot, after it cools it is going to be 96% of the measured volume. That is going to change the SG reading also.

After all is said and done, I think volume readings are probably only accurate to about +/- 2-5% and that could easily account for your SG readings.

Second, yes you can have Beersmith adjust your grain bill for different efficiencies. If you just adjust the efficiency on the main screen it will adjust the predicted SG of your wort. At the top of the recipe view there is a button that says "gravity." It is between "Color" and "Preview brewsheet." If you change the gravity there it will adjust your grain bill while keeping your efficiency the same.

NYCHomebrewer

Reelale said:

Doh! Thanks for pointing that out. That makes too much sense. I forgot about those additions. I feel so stupid.......

Click to expand...

Beersmith takes them into account, but often sugars and syrups are wildcards and boost more than intended based on when you add them, what exact type of sugar is used, etc.

NYCHomebrewer said:

Second, yes you can have Beersmith adjust your grain bill for different efficiencies. If you just adjust the efficiency on the main screen it will adjust the predicted SG of your wort. At the top of the recipe view there is a button that says "gravity." It is between "Color" and "Preview brewsheet." If you change the gravity there it will adjust your grain bill while keeping your efficiency the same.

NYCHomebrewer

Click to expand...

Thanks, I knew there was a way....

HarkinBanks said:

Beersmith takes them into account, but often sugars and syrups are wildcards and boost more than intended based on when you add them, what exact type of sugar is used, etc.

Click to expand...

Thanks. And it also helps if you remember that they go in the boil, not the mash! Sometimes the obvious eludes me.