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Head Scratcher Of A Problem: Measured Batch Size Into Fermenter

H

Hibs06

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So I'm going to try and explain this as best I can and hope I've done a good job.

On the design recipe tab there is a field where you enter in your batch size that will go into your fermenter, in my case I've been entering in 10 gallons.

When I enter in 10 gallons on the design recipe tab, that then is also shown in the fermentation tab as what is being entered into the fermentor and based of of this 10 gallons, the software calculates your estimated OG.  This is all fine and good until...

I bring my final boiling volume up to 10.92 gallons after my boil to account for the .92 gallons of wort I lose in my boil kettle and hoses on the way to the fermenter.  I've been putting in my final volume into the fermenter in the design tab as 10.92 gallons even though only 10 actually goes in.  So here's my problem I just came to find out...the software is basing it's IBU's, SRM, ABV, OG, etc. off of 10 gallons, but what I've been taking my readings at 10.92 gallons which means all of my IBU's, SRM, ABV,  and OG the software has been calculating are off...i.e. at 10 gallons not 10.92 even though only 10 gallons go into my fermenter.

What I believe I have to do is put my batch size in the design tab as 10.92 gallons as if that's what's going into the fermentor even though it's only 10 gallons actually going into the fermentor so that it calculates the IBU's, SRM, ABV, OG, etc. at the level I take my measurement.  Thoughts on this would be very helpful.  I hope I've explained this well enough.
 
If what you are saying is that BeerSmith is calculating your particulars at your batch size volume (10 G) and not your post-boil volume (10.92 G), it sounds like it's doing exactly what one would expect it to do - calculate your particulars for the volume you have going into the fermenter.

The only post-boil values I care about are the volume to confirm boil-off percentage, which stays between 14-15%/hr for my set-up, and the SG to be sure I've hit my target. I only care about BS2's calculated numbers for what I get in my fermenter because it is only THAT volume that turns into beer. The rest is chalked up to losses.

I also note that you are saying you are bringing your final volume up to 10.92 G after the boil. Are you topping up after you boil, or...? If you're adding water AFTER the boil to compensate for anticipated trub losses, you're effectively defeating what BS2 is trying to do for you. BS2 has built-in calculators for losses encountered during the brewing process. Let it do these calculations for you.

In any case; what you should care about most are the values BS2 will calculate into the fermenter because again; it's THAT volume that will ultimately turn into beer.

Oh; and the design tab is but one place to manipulate numbers albeit temporarily- if you want to set parameters for your equipment including batch size for every brew, use the Equipment Profile and save as "<whatever you want>" and then go into Options and select that profile for your brews. This way, each time you start a recipe, BS2 will drop your profile into that recipe and your batch size and all other calculated volumes will automatically show up in your design.
 
I'm with Phil.  I'm scratching MY head, trying to figure out why you are doing it that way. 

Tell beersmith what you are doing, and do what you tell beersmith (don't do something different).  Fill in the trub-loss field with 0.92 gallons, decrease your Brewhouse efficiency by 8-9% or so (or calculate it exactly). 
 
Ok, I was indeed having to add water back after the boil.  I see what you're both saying now and it sounds like my system details haven't been zero'd in exactly.  I'll be going back these week and recalculating everything. 
 
So my next question is:

Let's say I add .92 gallons to fill in the trub-loss field.  That's going to add .92 gallons to my starting boil volume.  At the end of the boil I should have enough wort to transfer out 10 gallons to my fermentor, but I'll still actually be taking measurements after the boil at 10.92 gallons.  If I have my batch size going into the fermenter set at 10 gallons then all my calculations will be off as I'll actually be measuring at 10.92 gallons, with the .92 being left over in the bottom of my boil kettle as loss. There is my problem.  Do I trick BeerSmith into thinking 10.92 gallons is my actual batch size going into the fermenter so the calculations will be correct?
 
The calculations shouldn't be off, and here's why: Independent of the amount of your post-boil volume you actually get out of your kettle and put into the fermenter, ALL of that post-boil volume will contain the same ratio of sugar and hops per measure of volume. Once you're done boiling, the volumes and ratios no longer change. This is why you take your OG reading post-boil.

With this new higher batch size, BeerSmith will also ask you for a little more sugar and hops to account for the new larger volume if you wish to maintain your original numbers.

Ultimately there will be 10.92 gallons of 1.065 wort with 75 IBUs (for example) in the kettle, and after draining there will be 10 gallons of 1.065 wort with 75 IBUs in the fermenter and 0.92 gallons of 1.065 wort with 75 IBUs in the kettle mixed with the trub - you'll just be leaving that last little bit in your kettle as your trub loss, and your calculated volume into the fermenter will be spot on. To be honest; I rarely get that close on my volumes anyway.

The calculated IBUs and OG are built in to the formulas in BS2 so when you design your recipe, it's all there for you. Whether or not you hit those targets is a function of brewhouse efficiency, and that often takes a while to dial in, which it seems you are doing now. I had mine set at the default value of 72% at first, and I found I was missing my targets so I dropped it down to 68% which seems to be more accurate, and will be bumping it up slowly with each brew until I'm consistently hitting my numbers.
 
Hello Philm,

The only problem from this (and maybe I'm wrong) is that you set your batch size according to what ends up in the fermentor and not what's in the kettle.  So, lets take your example.

My batch size into the fermentor is 10 gallons, but my batch size in my kettle post boil is 10.92 gallons with the .92 as a loss to trub.  If I set my batch size into fermenter at 10 gallons it's taking all of my readings (IBU's, ABV, Efficiency, etc.) based off of the 10 gallon batch size and not the actual 10.92 gallons post boil amount, which means my readings, for example, for efficiency will be measured off of 10.92 gallons and not the 10 gallons BeerSmith thinks the efficiency is based off of.  This will lead to a discrepancy due to the extra .92 gallons not going into the fermenter, but still being measured.  The only way I can think to correct this is to actually set my trub loss to 0 and put the 10.92 gallons as what's going into the fermenter that way it's actually taking my readings off of the entire 10.92 gallons post boil and not what's actually going into the fermenter which will be 10 gallons...WHEW! Make sense?



philm63 said:
The calculations shouldn't be off, and here's why: Independent of the amount of your post-boil volume you actually get out of your kettle and put into the fermenter, ALL of that post-boil volume will contain the same ratio of sugar and hops per measure of volume. Once you're done boiling, the volumes and ratios no longer change. This is why you take your OG reading post-boil.

With this new higher batch size, BeerSmith will also ask you for a little more sugar and hops to account for the new larger volume if you wish to maintain your original numbers.

Ultimately there will be 10.92 gallons of 1.065 wort with 75 IBUs (for example) in the kettle, and after draining there will be 10 gallons of 1.065 wort with 75 IBUs in the fermenter and 0.92 gallons of 1.065 wort with 75 IBUs in the kettle mixed with the trub - you'll just be leaving that last little bit in your kettle as your trub loss, and your calculated volume into the fermenter will be spot on. To be honest; I rarely get that close on my volumes anyway.

The calculated IBUs and OG are built in to the formulas in BS2 so when you design your recipe, it's all there for you. Whether or not you hit those targets is a function of brewhouse efficiency, and that often takes a while to dial in, which it seems you are doing now. I had mine set at the default value of 72% at first, and I found I was missing my targets so I dropped it down to 68% which seems to be more accurate, and will be bumping it up slowly with each brew until I'm consistently hitting my numbers.
Click to expand...
 
Hibs06 said:
Hello Philm,

The only problem from this (and maybe I'm wrong) is that you set your batch size according to what ends up in the fermentor and not what's in the kettle.  So, lets take your example.

My batch size into the fermentor is 10 gallons, but my batch size in my kettle post boil is 10.92 gallons with the .92 as a loss to trub.  If I set my batch size into fermenter at 10 gallons it's taking all of my readings (IBU's, ABV, Efficiency, etc.) based off of the 10 gallon batch size and not the actual 10.92 gallons post boil amount, which means my readings, for example, for efficiency will be measured off of 10.92 gallons and not the 10 gallons BeerSmith thinks the efficiency is based off of.  This will lead to a discrepancy due to the extra .92 gallons not going into the fermenter, but still being measured.  The only way I can think to correct this is to actually set my trub loss to 0 and put the 10.92 gallons as what's going into the fermenter that way it's actually taking my readings off of the entire 10.92 gallons post boil and not what's actually going into the fermenter which will be 10 gallons...WHEW! Make sense?
Click to expand...

No, that doesn't make sense.  Phil is correct. 

As long as you tell Beersmith that you have 0.92 gallons of trub loss, it will calculate your IBUs, pre-boil and post-boil SG etc. based on the volume of wort IN YOUR KETTLE (10.92 gallons). 

Brewhouse Efficiency is the percentage of sugars that make it INTO THE FERMENTER.  So, measuring that in the kettle makes no sense at all.  I don't want to argue if that is the right definition of Efficiency---it doesn't matter.  That's how BS2 does it.

For example:

You mash 20 lbs of 2-row malt, and get 83.33% efficiency, extracting 600 gravity units. 

You end up with 13 gallons of wort in your kettle (this includes the 0.92 gallons below your diptube).  This gives you a preboil SG of 1.046, which is what BS2 will tell you.

Now you boil down to 10.92 gallons.  This gives you a gravity of 1.055.  You still have 600 GU of sugar in the kettle.

finally you transfer 10 gallons of this wort to your fermenter.  This wort still has an SG of 1.055, but you left 0.92 gallons behind.  Now you have 550 GU of sugar in the fermenter and 50 GU in your kettle. 

BS2 will tell you that your brewhouse efficiency is 550/720 = 76.4%.  It will also tell you that your Mash Efficiency was 83.33%. 

There are many people who do not like this definition of efficiency, and do not like the fact that BS2 "back-calculates" what mash-efficiency you must have had.  Myself included.  But, that is not the point of this discussion.  The point is that BS2 WILL calculate everything correctly if you give it correct information. 


Now, ABV is entirely unrelated to your kettle data.  ABV is strictly related to the wort in your fermenter.  ABV is a ratiometric calculation based the difference between OG, and FG.  I don't even need to know the volume of a wort to calculate ABV. 
 
Ok, I totally get it.  Well then, in that case I'll enter in my system profile as it should be, putting my trub loss as it actually is and not at 0 like I was going to.  Thank you for explaining this to me.

tom_hampton said:
Hibs06 said:
Hello Philm,

The only problem from this (and maybe I'm wrong) is that you set your batch size according to what ends up in the fermentor and not what's in the kettle.  So, lets take your example.

My batch size into the fermentor is 10 gallons, but my batch size in my kettle post boil is 10.92 gallons with the .92 as a loss to trub.  If I set my batch size into fermenter at 10 gallons it's taking all of my readings (IBU's, ABV, Efficiency, etc.) based off of the 10 gallon batch size and not the actual 10.92 gallons post boil amount, which means my readings, for example, for efficiency will be measured off of 10.92 gallons and not the 10 gallons BeerSmith thinks the efficiency is based off of.  This will lead to a discrepancy due to the extra .92 gallons not going into the fermenter, but still being measured.  The only way I can think to correct this is to actually set my trub loss to 0 and put the 10.92 gallons as what's going into the fermenter that way it's actually taking my readings off of the entire 10.92 gallons post boil and not what's actually going into the fermenter which will be 10 gallons...WHEW! Make sense?
Click to expand...

No, that doesn't make sense.  Phil is correct. 

As long as you tell Beersmith that you have 0.92 gallons of trub loss, it will calculate your IBUs, pre-boil and post-boil SG etc. based on the volume of wort IN YOUR KETTLE (10.92 gallons). 

Brewhouse Efficiency is the percentage of sugars that make it INTO THE FERMENTER.  So, measuring that in the kettle makes no sense at all.  I don't want to argue if that is the right definition of Efficiency---it doesn't matter.  That's how BS2 does it.

For example:

You mash 20 lbs of 2-row malt, and get 83.33% efficiency, extracting 600 gravity units. 

You end up with 13 gallons of wort in your kettle (this includes the 0.92 gallons below your diptube).  This gives you a preboil SG of 1.046, which is what BS2 will tell you.

Now you boil down to 10.92 gallons.  This gives you a gravity of 1.055.  You still have 600 GU of sugar in the kettle.

finally you transfer 10 gallons of this wort to your fermenter.  This wort still has an SG of 1.055, but you left 0.92 gallons behind.  Now you have 550 GU of sugar in the fermenter and 50 GU in your kettle. 

BS2 will tell you that your brewhouse efficiency is 550/720 = 76.4%.  It will also tell you that your Mash Efficiency was 83.33%. 

There are many people who do not like this definition of efficiency, and do not like the fact that BS2 "back-calculates" what mash-efficiency you must have had.  Myself included.  But, that is not the point of this discussion.  The point is that BS2 WILL calculate everything correctly if you give it correct information. 


Now, ABV is entirely unrelated to your kettle data.  ABV is strictly related to the wort in your fermenter.  ABV is a ratiometric calculation based the difference between OG, and FG.  I don't even need to know the volume of a wort to calculate ABV.
Click to expand...
 
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