Boil off rates, trub loss etc

[NorthernBrew]

I am new to biab. On my 7th batch now. Very early got the beersmith 2 software. My setup is a 70 liter kettle with a 5500 w heating element, an immersion chiller. When i brew, i go for a 40 liter batch, which is around 10 gallons. I always put the recipe into the beersmith to check how much grain and hops to buy. But the thing i can not figure out is the total volume of water it suggests. If i mash on 67 celsius (152 fahrenheit) for 60 minutes, mashout on 77 celsius (170 fahrenheit) for 10 minutes, do a nice rolling boil for 60 minutes, chill, and strain my wort into the fermenter, aerate and pitch my rehydrated yeast, my fermentable wort is right around 10 gallons. For my 10gallon batch i need (in my experience) to start with about 14.3 gallons, but the beersmith suggests i start with over 17 gallons. Using the 14.3 i get the right batchsize and OG. So i do not understand why beersmith is calling for all this water. In a 60 min boil about 2 gallons evaporate. I strain into the fermenter so i extract most of the liquid from the kettle. Are you guys boiling so much more vigorously or leaving so much more in the kettle? I should mention that i do squeeze the mash bag once suspended for a few minutes. I would really like to know how much water you are starting with for the 10 gallon batches. I should also mention that i have tried some online biab calculators and they suggest varying volumes, from 17 to 15.5 gallons which is still way more than i use...
Sorry for the long question

 

[rlmiller10]

I am new to biab. On my 7th batch now. Very early got the beersmith 2 software. My setup is a 70 liter kettle with a 5500 w heating element, an immersion chiller. When i brew, i go for a 40 liter batch, which is around 10 gallons. I always put the recipe into the beersmith to check how much grain and hops to buy. But the thing i can not figure out is the total volume of water it suggests. If i mash on 67 celsius (152 fahrenheit) for 60 minutes, mashout on 77 celsius (170 fahrenheit) for 10 minutes, do a nice rolling boil for 60 minutes, chill, and strain my wort into the fermenter, aerate and pitch my rehydrated yeast, my fermentable wort is right around 10 gallons. For my 10gallon batch i need (in my experience) to start with about 14.3 gallons, but the beersmith suggests i start with over 17 gallons. Using the 14.3 i get the right batchsize and OG. So i do not understand why beersmith is calling for all this water. In a 60 min boil about 2 gallons evaporate. I strain into the fermenter so i extract most of the liquid from the kettle. Are you guys boiling so much more vigorously or leaving so much more in the kettle? I should mention that i do squeeze the mash bag once suspended for a few minutes. I would really like to know how much water you are starting with for the 10 gallon batches. I should also mention that i have tried some online biab calculators and they suggest varying volumes, from 17 to 15.5 gallons which is still way more than i use...
Sorry for the long question

Go to the volumes tab on beersmith and look at the boil off volume. Also look at the trub loss. I am guessing it is assuming more boil off. If you have your numbers from experience for grain absorption, boil off, tun deadspace and trub loss you can put all of those in your equipment profile and it should come out correct. Some place beersmith is assuming you are loosing water you are not. By looking at the volumes which beersmith estimates at the various stages such as start, preboil, post boil, chill loss.... and compare to your numbers from experience you should be able to adjust the profile to match reality.

 

[NorthernBrew]

Go to the volumes tab on beersmith and look at the boil off volume. Also look at the trub loss. I am guessing it is assuming more boil off. If you have your numbers from experience for grain absorption, boil off, tun deadspace and trub loss you can put all of those in your equipment profile and it should come out correct. Some place beersmith is assuming you are loosing water you are not. By looking at the volumes which beersmith estimates at the various stages such as start, preboil, post boil, chill loss.... and compare to your numbers from experience you should be able to adjust the profile to match reality.

Thanks. Seems to me that the biggest reason is the trub loss, wich is set at 1.5 gallons when in my system it is almost 0,0

 

[wilserbrewer]

What truly matters is the volume in your kettle, and NOT what Beersmith tells you should be in your kettle!

Your process and ability to seems fine, keep up the good work! Beersmith is a great tool, however knowing when to not blindly follow it is invaluable.