Lauter tun deadspace doesn't affect Est. Pre-boil Gravity

I'm on Windows XP using BS 2.1.02 but it seems the same behavior exists in version 1.4 as well.

First, I made a copy of my Equipment Profile that I'll call Profile 1.  I'll call the copied profile Profile 2.  On Profile 2 I modified both the Lauter Tun Deadspace and the Loss to Trub and Chiller value.  Profile 1 has 2.00g of MLT deadspace and 1.50g of loss to trub.  On Profile 2 I changed both to zero.  Every other parameter is identical.

I did two tests, both with different (unexptected) outcomes.

Test 1 : My original recipe using Profile 1 has an est. pre-boil gravity of 1.041.  In the recipe build screen I then changed the Equipment to use Profile 2 via the dropdown and the est. pre-boil gravity was lowered (as expected) to 1.038.  When I switched *back* to Profile 1 via the dropdown, the Est. Pre-Boil gravity went back to only 1.040.  :-\

Test 2 : Another possible bug I came across is when I modify Profile 1 by setting the MLT deadspace and trub loss to 0 from the recipe page (by pressing the checkmark button - as opposed to modifying the profile from the Profiles left hand menu) the gravity gets set to 1.040.  I would have expected the value to be the same as Test 1, 1.038 since the same parameters where changed just in a different manner.

Thoughts?

Thanks.

I have seen answers here that indicate that certain pages/screens in BeerSmith do need to be closed/saved and reopened for all changes to take effect. 

So I'd recommend you check that out and verify that's not the issue.

wizardofza said:

I'm on Windows XP using BS 2.1.02 but it seems the same behavior exists in version 1.4 as well.

First, I made a copy of my Equipment Profile that I'll call Profile 1.  I'll call the copied profile Profile 2.  On Profile 2 I modified both the Lauter Tun Deadspace and the Loss to Trub and Chiller value.  Profile 1 has 2.00g of MLT deadspace and 1.50g of loss to trub.  On Profile 2 I changed both to zero.  Every other parameter is identical.

I did two tests, both with different (unexptected) outcomes.

Test 1 : My original recipe using Profile 1 has an est. pre-boil gravity of 1.041.  In the recipe build screen I then changed the Equipment to use Profile 2 via the dropdown and the est. pre-boil gravity was lowered (as expected) to 1.038.  When I switched *back* to Profile 1 via the dropdown, the Est. Pre-Boil gravity went back to only 1.040.  :-\

Click to expand...

When you switch profiles, you would also need to use the 'scale recipe' tool to keep OG, IBU, SRM, etc. the same when switching profiles.  If you don't do this, I believe some numbers are reused by BeerSmith, even though they are from the previous profile.

Even stranger things will happen if you scale to more than one profile, then back to the original.  These aren't small errors, they are gallons of water, and pounds of grain errors.  Not to worry though, since BeerSmith tells you the OG, IBU, SRM, etc are the still the same, magically.  A good rule of thumb/workaround is to build the recipe on one equip profile, then copy (and rename) the recipe and scale it in a new tab.  Use a 'new' copy of the original for each different 'test' you are playing around with.

wizardofza said:

Test 2 : Another possible bug I came across is when I modify Profile 1 by setting the MLT deadspace and trub loss to 0 from the recipe page (by pressing the checkmark button - as opposed to modifying the profile from the Profiles left hand menu) the gravity gets set to 1.040.  I would have expected the value to be the same as Test 1, 1.038 since the same parameters where changed just in a different manner.

Thoughts?

Thanks.

Click to expand...

This is a rounding error artifact due to how BeerSmith generates it numbers- 'backing into the recipe', as they say.  Not saying it is correct, but the root cause is that you kept your efficiency number, which is 'to the fermenter', the same for both profiles.  Check the estimated mash efficiency BeerSmith came up with for each, and you will see how it kept the OG very close to the same, even though there are now sugar losses.  This is either a feature or a bug, depending on your bent.

There is a larger issue, and that is how much would need to adjust your efficiency down for the profile with trub losses.  The amount to decrease it by is close to the amount you could figure by hand calcs due to lost sugars in the trub, but it won't be exact because trub loss impacts BeerSmith calcs at least twice.  Once in the kettle, and again after, because efficiency is 'to the fermenter'.  The hand calc will get you very close for normal trub amounts, since the secondary effect is a small percentage of the initial decrease.  To calculate it properly would take some higher math that isn't worth the effort.  It is easier to add an extra 1% to the calc'd decrease, and call it good.

Another way, oft suggested here, is to leave the efficiency the same initially, and then brew the recipe a few times. The rationale being keeping track of your numbers, you will home in on the correct efficiency number to use, eventually.  Both ways seem a little peculiar to me.  I would expect the software to either assist in calculating the new reduced efficiency; or handle trub losses in a more normal fashion and scale the recipe up to account for them.

MaltLicker said:

I have seen answers here that indicate that certain pages/screens in BeerSmith do need to be closed/saved and reopened for all changes to take effect. 

So I'd recommend you check that out and verify that's not the issue.

Click to expand...

For the OP's issue, he switched backed to the original profile, so I don't think this would be the cause.
I haven't noticed BeerSmith showing bad calcs because of 'saving' issues, but it wouldn't surprise me in the least if that is the case.  Sometimes it requires clicking another field to trigger a screen recalc, which is reasonable.

I think my explanation is more plausible.  For some more related fun, check out this thread-
http://www.beersmith.com/forum/index.php/topic,7459.0.html