OK, here is how I tuned my profiles and how I keep them updated:
You want to get the most accurate measurements you can on (1) volume of mash water [Vm], (2) weight of grains [Wg], (3) volume of wort collected pre-boil [Vp], (4) specific gravity of wort collected pre-boil [Sp], (5) volume of wort post-boil [Vb], (6) specific gravity of wort post boil [Sb], (7) volume into fermentor [Vf], (8) volume of trub/waste [Vt], (9) Boil time [T], (10) dead space volume in mash tun [Vd].
The more accurate you can take these readings the easier and faster it will be to tune your BeerSmith profiles.
The first thing you want to do is correct your volumes for room temperature. Expansion of water is 4% at near boiling temperatures. For simplicity, I use this figure (4%) for my hot measurements since I usually have them heating towards boil when I take them.
[Vm] is measured at room temperature (in my case)
[Vp] is corrected for expansion: [Vp] / 1.04 = [Vpc]
[Vb] is corrected for expansion: [Vb] / 1.04 = [Vbc]
My volumes into the fermentor [Vf], volume of your mash tun dead space [Vd], and volume of waste and trub [Vt] are taken at room temperature
Your grain absorption is: ( [Vm] - [Vpc] - [Vd]) / [Wg]
Your boil off rate is: ( [Vpc] - [Vbc] ) / [T]
Checking your measurements:
I always run a gravity point balance around the boil to check the accuracy of my measurements. This can be done by converting your specific gravity readings to 'points' using the following equations:
Points pre-boil: ( [Sp] - 1.000) * 1000 = [Pp]
points post boil: ( [Sb] - 1.000) * 1000 = [Pb]
Your balance is gravity points pre-boil should equal gravity points post boil, thus:
( [Vpc] * [Pp] ) - ( [Vbc] * [Pb] ) should equal zero, or close enough within your margin of error for measurements.
Now take your grain absorption figure and update it into BeerSmith by clicking 'options' >> 'advanced' and under 'Grain absorption' enter your recorded figure.
Take your equipment profile and update the figures for 'mash tun deadspace' to your measured [Vd]
Update your boil off rate by entering your calculated boil off per hour in the space marked 'boil off' and clicking 'use boil off as hourly rate'
Enter boil time as your standard boil for the majority of your recipes. This only sets the initial boil time and can be adjusted within a recipe after updating the profile.
Update your mash tun volume and weight, your typical kettle top off (if any), top off water to fermentor (if any), and expected trub left in fermentor.
You can enter your 'loss to trub and chiller' using [Vt].
You can check your post boil volume measurement by comparing [Vbc] - [Vf] - [Vt] should be close to zero.
Now for the easy part, look at the last recipe you brewed and make sure the user entry numbers are all filled in on the mash tab and the post boil numbers on the fermentation tab.
BeerSmith will give you your 'measured mash efficiency' on the mash tab and your 'measured brewhouse efficiency' on the fermentation tab. Enter the measured brewhouse efficiency from the recipe into your equipment profile.
Generally, if you have good enough measurements you can fine tune BeerSmith to be pretty accurate within 3 to 4 brews. I keep a spreadsheet with the calculations described above for each brew and look at the averages in order to update my equipment profile on a regular basis, about every 3 to 4 months. At 102 brews right now, most changes I make are very, very minor and most times I don't even bother because it is well within my ability to measure such changes. The spreadsheet also let me look at any trends as I improved my process.
Last note: I follow Mash Efficiency more closely than I do brewhouse efficiency. My mash efficiency is extremely predictable, whereas my brewhouse efficiency changes depending upon the volume of hops added, for which I adjust the loss to trub and chiller for each recipe before I brew it. I then adjust the brewhouse efficiency to obtain the mash efficiency I know that I will hit.
