Author Topic: Final Volume, Boil Trub and Chiller Losses Effect on OG -- Continued  (Read 6662 times)

Offline Freshness

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Hi,

I've been looking into this issue http://www.beersmith.com/forum/index.php?topic=1504.0 and I believe it is still unresolved and/or broken. 

I too have been puzzled by the discrepancy in the two 'methods' of computing the gravity and I am pretty certain that Beersmith is making a mistake.  Here is a simple thought exercise that should illustrate my reasoning:  If I take 10 gallons of wort with an OG of 1.048 and split it into two carboys, the OG of the wort in each carboy is still 1.048, logically.  The gravity did not change.   Similarly, if I leave a gallon of wort in the kettle, or two gallons, or any amount, the gravity in the fermenter does not change.  Therefore changing the "Loss to Boil Trub and Chiller" parameter in the equipment customization screen should have absolutely no effect on the wort's gravity. 

My current version of the software (1_40 build 37) does not account for this loss wort properly and changes the gravity as this value changes, as if the loss was taken out of the pre-boil water instead of post-boil wort. 

Are there any plans on fixing this problem?  It's easy enough to work around once you know there is a bug, however it threw me for a loop for a few days trying to track down why my gravities were off from the published recipes I was attempting to model.

By the way - Thanks for the great software!

Cheers,
  Ray



Offline BeerSmith

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Re: Final Volume, Boil Trub and Chiller Losses Effect on OG -- Continued
« Reply #1 on: April 22, 2009, 07:37:38 AM »
Ray,
  This has to do with the definition of brewhouse efficiency which is covered here: http://www.beersmith.com/blog/2008/10/26/brewhouse-efficiency-for-all-grain-beer-brewing/

  What you are describing is a system that uses mash efficiency instead of brewhouse efficiency and then calculates losses from there forward.  Such a thing is certainly possible (in fact the efficiency button shows a lot of the data) but is not in the current version.  I am looking at adding it to a future version.

Cheers,
Brad
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Offline Freshness

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Re: Final Volume, Boil Trub and Chiller Losses Effect on OG -- Continued
« Reply #2 on: April 22, 2009, 10:06:13 AM »
  What you are describing is a system that uses mash efficiency instead of brewhouse efficiency and then calculates losses from there forward. 

Ahh -  I think I get it now.  Yes, I believe that many all-grain home brewers think in terms of mash efficiency, or at least I do.  However, I still believe it is a mistake for the OG to change due to changes in the wort loss, regardless of whether you think in terms of brewhouse or mash efficiency.  Maybe it's an interface issue?  When a user changes that loss number - the brewhouse efficiency should be recomputed rather than change the output values, perhaps.

Cheers,
  -Ray

Offline MaltLicker

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Re: Final Volume, Boil Trub and Chiller Losses Effect on OG -- Continued
« Reply #3 on: April 22, 2009, 10:40:33 AM »
............However, I still believe it is a mistake for the OG to change due to changes in the wort loss, regardless of whether you think in terms of brewhouse or mash efficiency.....When a user changes that loss number - the brewhouse efficiency should be recomputed rather than change the output values, perhaps.

The question (to me) comes down to why would I change an equipment/brewhouse EE% number after the fact for a finished brew?  IMO, the equipment settings are for "dialing in " the static characteristics of my given equipment.  It is what it is, assuming I've measured things well.  If I discover something wrong, like when I realized my bottling bucket is mismarked, I fix it for the next time.  (If I drop wort on the floor, that is clumsiness, not a loss of efficiency on that batch.) 

The mash EE% numbers, however, are for calculating how I (as brewer) performed with that given equipment with the grains and conditions on hand (ambient temps, rye/wheat stickiness, adjuncts, whatever). 

Once precisely measured, equipment is static, but my performance as brewer with the brew at hand varies each time.  So the goal (again IMO) would be for each brewer to isolate the known equipment variance in those settings, and then fine-tune our "operator error" downward, increasing mash efficiency, which would pull up overall brewhouse efficiency.  I will hit a wall when I've done all I can with process, unless I upgrade to more efficient/repeatable equipment. 



Offline Freshness

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Re: Final Volume, Boil Trub and Chiller Losses Effect on OG -- Continued
« Reply #4 on: April 22, 2009, 11:07:56 AM »

The question (to me) comes down to why would I change an equipment/brewhouse EE% number after the fact for a finished brew?  IMO, the equipment settings are for "dialing in " the static characteristics of my given equipment. 


I agree - maybe I wasn't clear, but I was trying to do initial setup of my system.  I know I leave a certain amount of wort behind when I transfer to the fermentor.  I don't think changing that value should affect my wort's gravity.  Logically, it changes the brewhouse efficiency - however that parameter is buried in the options menu - not on the equipment page.  Maybe that's where it belongs, but ironically I can't change its value since I'm an extract brewer. 

Come to think of it, that may be another bug: brewhouse efficiency affects both extract and all-grain brewers and should be settable by both.  Mash efficiency is of course an all-grain parameter.

But a better way may be to automatically compute the brewhouse efficiency for either extract or all-grain brewers for a chosen set of equipment since it's a measure of the entire process.  Then, allow all-grain brewers to estimate and enter their mash efficiency.

Regards,
 Ray
« Last Edit: April 22, 2009, 04:19:05 PM by Freshness »

 

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