Double batch hit my OG, single batch out by 10 points

[JRazz]

Hey everyone looking for some reasons why this might be the case. Yesterday i did 2 brews of the same beer, the first batch i did i doubled it up so it was 46L batch in a 70L pot. Everything went great only had to take out a little water to fit all the grain into the pot, the weird thing is the single batch i did straight after ended up 10 points short and i have no idea why. This was my first double i had done and it properly went better than any other single brew i have ever done. All of my calculations were done in beer smith and it was a very long brew day

 

[Oginme]

I am guessing that you used the same equipment profile for both batches. The equipment profile used the same brew house efficiency (BHE) for both brews. However, when you made both of the recipes on the same equipment, you had the same losses for both recipes. Meaning that if brew number 1 (the 2X brew) lost 6 liters in your process that your brew number 2 (1X brew) most likely lost the same volume.

The program, not knowing any better, just jacked up the mash efficiency to account for the additional percentage loss of sugar in the second batch. The program does this because it relies on the BHE to determine how much sugar from the mash makes it into the fermenter. It then back calculates the mash efficiency to achieve this end, regardless of the actual mash efficiency you can attain with your system. So when you made the second batch and you added more water based and (had a higher water to grain ratio) to compensate for the losses and had about the same mash efficiency as the 2X batch, you actually were diluting the concentration of the sugars with that additional volume.

When I have done similar things in the past (changing volume with the same equipment profile), I have adjusted the BHE to compensate for the additional percentage of volume loss to keep about the same mash efficiency coming out of the mash and it has always worked out fine.

 

[JRazz]

I am guessing that you used the same equipment profile for both batches. The equipment profile used the same brew house efficiency (BHE) for both brews. However, when you made both of the recipes on the same equipment, you had the same losses for both recipes. Meaning that if brew number 1 (the 2X brew) lost 6 liters in your process that your brew number 2 (1X brew) most likely lost the same volume.

The program, not knowing any better, just jacked up the mash efficiency to account for the additional percentage loss of sugar in the second batch. The program does this because it relies on the BHE to determine how much sugar from the mash makes it into the fermenter. It then back calculates the mash efficiency to achieve this end, regardless of the actual mash efficiency you can attain with your system. So when you made the second batch and you added more water based and (had a higher water to grain ratio) to compensate for the losses and had about the same mash efficiency as the 2X batch, you actually were diluting the concentration of the sugars with that additional volume.

When I have done similar things in the past (changing volume with the same equipment profile), I have adjusted the BHE to compensate for the additional percentage of volume loss to keep about the same mash efficiency coming out of the mash and it has always worked out fine.

Interesting and i totally understand what you are talking about and see how that could happen but I did change the equipment profile.... weird. Ill attach the brew doc below for both. much appreciated for your help.

BeerSmith 2 Recipe Printout - http://www.beersmith.com
Recipe: American IPA - Double
Brewer:
Asst Brewer:
Style: American Amber Ale
TYPE: All Grain
Taste: (30.0)

Recipe Specifications
--------------------------
Boil Size: 57.96 L
Post Boil Volume: 48.96 L
Batch Size (fermenter): 46.00 L
Bottling Volume: 44.00 L
Estimated OG: 1.057 SG
Estimated Color: 14.6 EBC
Estimated IBU: 60.4 IBUs
Brewhouse Efficiency: 68.00 %
Est Mash Efficiency: 69.5 %
Boil Time: 60 Minutes

Ingredients:
------------
Amt Name Type # %/IBU Volume
10.00 kg Pale Malt (2 Row) US (3.9 EBC) Grain 1 78.5 % 6.52 L
1.12 kg Biscuit Malt (45.3 EBC) Grain 2 8.8 % 0.73 L
1.12 kg Munich Malt - 10L (19.7 EBC) Grain 3 8.8 % 0.73 L
0.50 kg Gladfield Ale Malt (6.0 EBC) Grain 4 3.9 % 0.33 L
72.00 g Chinook [13.00 %] - Boil 60.0 min Hop 5 49.0 IBUs -
60.00 g Centennial [10.00 %] - Boil 10.0 min Hop 6 11.4 IBUs -
76.00 g Cascade [5.50 %] - Boil 0.0 min Hop 7 0.0 IBUs -


Mash Schedule: BIAB, Full Body
Total Grain Weight: 12.74 kg
----------------------------
Name Description Step Temperat Step Time
Saccharification Add 65.75 L of water at 73.1 C 68.9 C 60 min
Mash Out Heat to 75.6 C over 7 min 75.6 C 10 min

Sparge: If steeping, remove grains, and prepare to boil wort
Notes:
------
1.059 pre boil added 5 L

Created with BeerSmith 2 - http://www.beersmith.com
-------------------------------------------------------------------------------------

BeerSmith 2 Recipe Printout - http://www.beersmith.com
Recipe: American IPA single
Brewer:
Asst Brewer:
Style: American Amber Ale
TYPE: All Grain
Taste: (30.0)

Recipe Specifications
--------------------------
Boil Size: 36.08 L
Post Boil Volume: 27.08 L
Batch Size (fermenter): 23.00 L
Bottling Volume: 22.00 L
Estimated OG: 1.059 SG
Estimated Color: 13.9 EBC
Estimated IBU: 59.5 IBUs
Brewhouse Efficiency: 68.00 %
Est Mash Efficiency: 76.9 %
Boil Time: 60 Minutes

Ingredients:
------------
Amt Name Type # %/IBU Volume
5.00 kg Pale Malt (2 Row) US (3.9 EBC) Grain 1 75.5 % 3.26 L
0.56 kg Biscuit Malt (45.3 EBC) Grain 2 8.5 % 0.37 L
0.56 kg Munich Malt - 10L (19.7 EBC) Grain 3 8.5 % 0.37 L
0.50 kg Gladfield Ale Malt (6.0 EBC) Grain 4 7.6 % 0.33 L
38.03 g Chinook [13.00 %] - Boil 60.0 min Hop 5 48.3 IBUs -
31.69 g Centennial [10.00 %] - Boil 10.0 min Hop 6 11.2 IBUs -
38.00 g Cascade [5.50 %] - Boil 0.0 min Hop 7 0.0 IBUs -


Mash Schedule: BIAB, Full Body
Total Grain Weight: 6.62 kg
----------------------------
Name Description Step Temperat Step Time
Saccharification Add 40.13 L of water at 72.6 C 68.9 C 60 min
Mash Out Heat to 75.6 C over 7 min 75.6 C 10 min

Sparge: If steeping, remove grains, and prepare to boil wort
Notes:
------
1.059 pre boil added 5 L

Created with BeerSmith 2 - http://www.beersmith.com
-------------------------------------------------------------------------------------

 

[Oginme]

Right, but you did not change the BHE to compensate for additional water requirement and sugar losses associated with them.

In your 2x batch, you add 65.75 l of water for 12.74 kg of grain which gives you a water to grain ratio in the mash tun of 5.16 L/Kg

In your 1x batch, you are adding 40.13 l of water for 6.62 kg of grain which gives you a water to grain ratio in the mash tun of 6.06 L/Kg

BeerSmith responds to this dilution by increasing your mash efficiency from 69.5% for the 2x batch up to 76.9% for the 1x batch. With your system giving you a mash efficiency of 69.5%, what would suddenly cause it to become that much higher? (I will admit here that the greater amount of water will increase your mash efficiency slightly, but not that much). Instead the additional water dilutes your sugar content, giving you a lower gravity for the 1x batch than you planned. If you entered your actual values into the 'sessions' tab, the program will calculate out the actual BHE and Mash efficiency on that tab. This will confirm some of what you are experiencing.

On another note, your mash efficiency is quite low and you should look at the crush of your grains to see if you can increase your yield.