DrStrangebrew
New Member
Hi Brewtarget Experts!
I downloaded Brewtarget 1.2.4 and am having some trouble reproducing the results by hand. Here is a simple example with even numbers....
Calculating it by hand:
I want 10 gallons of wort to go into my fermenter. 1 gallon will evaporate during the 60min boil, and 2 gallons will remain in the kettle as trub waste. So my start boil is 13 gallons, end boil is 12 gallons.
I will mash 20# of 2-row @ 70% efficiency. Total points sugar = 20# * 46 PPG * 79% yield * 70% efficiency = 509 points. The 79% yield is the number used by Brewtarget.
Therefore my preboil SG will be 509/13 gall = 39 (1.039) and my postboil SG (or OG) will be 509/12 gall = 42 (1.042). The 2 gallons of trub and 10 gallons in the fermenter should have the same SG.
Now entering it in Brewtarget:
I made a new equipment with 10 gal batch size, 1 gallon per hour evaporation rate and 2 gallon kettle to fermenter losses. I checked "calculate pre-boil volume" and it gives me the correct 13 gallons. I put 20# of 2-row in the grain bill, do a one step infusion mash (154 deg for 60 min), hit "mash wiz" key (use 1 qt/#) and here is what I get.
The OG is 1.051 (not 1.042). It would be 1.051 if you divided points by batch 509/10 gall, but there is 12 gall in kettle.
Likewise the (pre?) Boil SG is 1.047 (not 1.039). It would be 1.047 if you divided points (509) by 11 gall, but there is 13 gall in the kettle.
I guess my question boils down to what is the kettle to fermenter loss in the equipment setup? Is that wort left behind in the kettle as trub? Everything works great if I make my batch size 12 gallon (10 in fermenter + 2 trub) and leave the "kettle to fermenter loss" as zero, but is that how I'm supposed to use the program? If so, what is the "kettle to fermenter loss" entry for? Does batch size equal fermenter plus trub? The equipment window calculates pre-boil volume equals batch size plus Kettle to fermenter loss.
Wheww!! I'm done now!
I hope someone can shed some light on this. I'm really excited about learning this program!
I downloaded Brewtarget 1.2.4 and am having some trouble reproducing the results by hand. Here is a simple example with even numbers....
Calculating it by hand:
I want 10 gallons of wort to go into my fermenter. 1 gallon will evaporate during the 60min boil, and 2 gallons will remain in the kettle as trub waste. So my start boil is 13 gallons, end boil is 12 gallons.
I will mash 20# of 2-row @ 70% efficiency. Total points sugar = 20# * 46 PPG * 79% yield * 70% efficiency = 509 points. The 79% yield is the number used by Brewtarget.
Therefore my preboil SG will be 509/13 gall = 39 (1.039) and my postboil SG (or OG) will be 509/12 gall = 42 (1.042). The 2 gallons of trub and 10 gallons in the fermenter should have the same SG.
Now entering it in Brewtarget:
I made a new equipment with 10 gal batch size, 1 gallon per hour evaporation rate and 2 gallon kettle to fermenter losses. I checked "calculate pre-boil volume" and it gives me the correct 13 gallons. I put 20# of 2-row in the grain bill, do a one step infusion mash (154 deg for 60 min), hit "mash wiz" key (use 1 qt/#) and here is what I get.
The OG is 1.051 (not 1.042). It would be 1.051 if you divided points by batch 509/10 gall, but there is 12 gall in kettle.
Likewise the (pre?) Boil SG is 1.047 (not 1.039). It would be 1.047 if you divided points (509) by 11 gall, but there is 13 gall in the kettle.
I guess my question boils down to what is the kettle to fermenter loss in the equipment setup? Is that wort left behind in the kettle as trub? Everything works great if I make my batch size 12 gallon (10 in fermenter + 2 trub) and leave the "kettle to fermenter loss" as zero, but is that how I'm supposed to use the program? If so, what is the "kettle to fermenter loss" entry for? Does batch size equal fermenter plus trub? The equipment window calculates pre-boil volume equals batch size plus Kettle to fermenter loss.
Wheww!! I'm done now!
I hope someone can shed some light on this. I'm really excited about learning this program!
