Author Topic: Loss to Trub and Chiller (EQUIPMENT PROFILE) error  (Read 3940 times)

Offline zaluskim@gmail.com

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Loss to Trub and Chiller (EQUIPMENT PROFILE) error
« on: November 06, 2014, 10:59:41 PM »
A change in this value does not change the OG of the wort - but it should.  If I have a loss of 4 gallons to the trub, then obviously the same amount of sugar is diluted by that many more gallons - and yet the OG stays the same in the calculations.

I read in another post that BS is keeping the OG the same because it's estimating a greater efficiency from the mash based on additional sparge volume, but that's unrealistic beyond a finite efficiency. 

Please fix.  Thanks.
marty

Offline brewfun

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Re: Loss to Trub and Chiller (EQUIPMENT PROFILE) error
« Reply #1 on: November 07, 2014, 02:13:49 AM »
You're confusing mash efficiency and brewhouse efficiency. This is actually the correct way for efficiency to be calculated when the Brewhouse Efficiency is the determining factor. What you're describing is based on mash efficiency being constant.

Brewhouse Efficiency is the percentage of sugar that makes it to the fermenter. This means that if you have 1 gallon of trub loss, and 4 gallons make it to the fermenter, you have 80% of the sugars extracted getting to the fermenter. Thus, 80% Brewhouse Efficiency is the highest possible number.

If you know you'll get 70% of the total available sugar from the grain, this reduces your brewhouse efficiency from the maximum illustrated above. If you measure your wort at the higher gravity with more volume, then the ONLY possible place to gain that sugar is with better mash efficiency.

If you're more comfortable making your batch size measurements in the kettle, then set trub loss to zero to make the Brewhouse Efficiency the same as Mash Efficiency. A future update may have the option to let mash efficiency be the determining calculation. With that, the brewhouse efficiency and OG will decrease with increasing loss to trub.
« Last Edit: November 07, 2014, 02:19:49 AM by brewfun »
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Offline Oginme

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Re: Loss to Trub and Chiller (EQUIPMENT PROFILE) error
« Reply #2 on: November 07, 2014, 05:47:10 AM »
Brewfun,

I hope that the next big update to BeerSmith does key on Mash Efficiency and Volume at the end of boil.  These in my system are the most consistent values.  Depending upon the recipe, the amount of trub left behind can vary greatly (i.e. more hops -- more trub loss).  This effects the brewhouse efficiency but not the mash efficiency.

Brad, I hope you take note of this!

-- Old Goat
Recycle your grains, feed them to a goat!

Offline brewfun

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Re: Loss to Trub and Chiller (EQUIPMENT PROFILE) error
« Reply #3 on: November 08, 2014, 06:10:21 PM »
Oginme;

Agreed. I'm looking forward to having the option to use mash efficiency as the constant. It'll also illustrate the difference between the two methods more clearly.

There's a trend among newer brewers to rely on software to give all of the answers they're looking for and to have various sources agree. That's validation instead of information. New brewers need to spend the time and brain cells learning the theory behind the calculations, so they know how they work.

It's not uncommon for me to pencil out calculations when I'm troubleshooting someone's post, here. When  checked against what BeerSmith predicts, it's usually possible to spot the variable that needs adjustment by the brewer.
Beer Appreciation is the space between pints.

Offline zaluskim@gmail.com

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Re: Loss to Trub and Chiller (EQUIPMENT PROFILE) error
« Reply #4 on: November 09, 2014, 12:31:44 AM »
Thank you both.  I came across this by wanting to increase my trub loss in the 'Equipment Profile' so I could siphon off a few liters for a starter, and still have my 5.5gal batch - what I discovered is that no matter how much I increased the trub loss, my OG did not change - Which again, is illogical because I have the same amount of sugar but diluted over the increased volume (boil volume and trub loss.) 

Thanks for the under-the-hood peek that BS uses Brewhouse efficiency to calculate the OG. In this scenario, it looks like it yields erroneous results.  However, it looks like increasing 'Batch Size' on the recipe design page and scaling the recipe to the new volume will do the trick. 

Offline brewfun

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Re: Loss to Trub and Chiller (EQUIPMENT PROFILE) error
« Reply #5 on: November 09, 2014, 06:13:58 AM »
In this scenario, it looks like it yields erroneous results.  However, it looks like increasing 'Batch Size' on the recipe design page and scaling the recipe to the new volume will do the trick.

Just reducing the Brewhouse Efficiency by the same percentage as the accumulated Loss to Trub is the best way to accomplish that.
Beer Appreciation is the space between pints.