[EDIT: Spent an hour rambling the below, probably to myself
so missed Yeasty's post above
]
Tarmac, I'm going tag team with Yeasty. He's answered the hard question on how to get the two calculators to match so I'll go the easy question on the trub.
Mathematical Side
Both of the calculator spreadsheets and all existing brewing software have severe limitations on trub estimations. In fact,
no major software even bothers trying to estimate trub - it's left entirely up to the individual. "The Calculator"'s aim (and the BIABAcus is following that aim) is to get brewers under way with as few decisions as possible. So, "The Calculator," has evaporation and trub estimate formulas you won't find anywhere else or, if you do, they originated from "The Calculator". As Yeasty has pointed out, stux adjusted some of the base trub calcs from "The Calculator" to suit his own equipment, hence the mis-match of estimates but...
Here's what you should know...
"The Calculator," trub estimates are deliberately on the high side. The reason for this is that the worst that can happen is you will get more beer than you expected. (The gravity should remain unaffected.) If you use a hop sock you could halve the kettle trub losses predicted by "The Calculator". If you crash-chill your primary before kegging or if you use a secondary before bottling, you could halve the fermentor losses predicted by, "The Calculator".
What You Should Do Now
Whilst, 'The Calculator," gives a starting point for you (to get you into the ballpark), don't treat it as gospel. You can reduce kettle trub losses dramatically by using a hopsock or a successful whirlpool. Fermentor trub can be reduced by crash-chilling before transfer to packaging. So, explore those options and don't be surprised if you do better than the "BrewLength" predicted in "The Calculator". ("BrewLength," will become "Volume into Packaging" in the BIABacus.)
If you find yourself with less trub than The Calculator predicts, just change cell B6 to "=B5*0.04" to change the fermentor loss or...
Cell B 8 to "=B5*0.09". (Don't publish your variation though as it will confuse everone!!!) These are just examples.
BIABacus Trub Improvements on "The Calculator"
I know that everyone is sick of hearing about the BIABacus and wants to see it tomorrow
but The BIABacus is nothing more than a much better version of The Calculator. It requires less inputs by a new user but allows for faster and more accurate control than any advanced user could hope for or find anywhere else. For example, if the new brewer touches nothing in the BIABacus, trub estimates are automatically done at a high estimate. If the intermediate user types Y on two fields, kettle and fermentor loss estimates are automatically reduced. The advanced user can go further and over-ride these estimates in several different ways.
One thing we haven't explored on trub...
The amount of hops used in a recipe have a dramatic affect on trub. Like so many other brewing figures, there is virtually no quality information on this. What little there is disagrees. So, if we haven't got good info on this, well
.
Apologies for what is probably a ramble Tarmac,
PP
P.S. (The BIABAcus guys have given up on working out how to write a complete help for the BIABAcus as it will take a small book. So, the BIABAcus, without comprehensive, clickable help
should be here sooner than thought
. Instead of the exhaustive help envisioned it looks like initial help will be given to members here. Better than waiting another year
.
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