# Water Volumes and Temperature Correction

Discussion in 'Recipe Editor' started by Craigerrr, Dec 15, 2019.

1. ### Craigerrr Well-Known Member

Joined:
Mar 14, 2018
Messages:
4,700
6,899
Trophy Points:
113
#1
So the accepted water volume correction as I understand it is generally accepted as 4%. Does the recipe editor and the volumes referred to take this into account?

For instance does preboil volume account for the thermal expansion of the usually 150F ish wort temperature?

Similarly is post boil volume based on post cooling volume, or is the volume based on the corrected volume of 200F+ degree wort?

2. ### Pricelessbrewing QA Software Tester Staff Member

Joined:
Jun 8, 2016
Messages:
764
502
Trophy Points:
93
Gender:
Male
#2
I could be wrong, as I haven't done any audit or testing on this feature yet, but there's a user setting "Cooling shrinkage" in your equipment profile for this.

https://www.brewersfriend.com/homebrew/profile/equipment

As far as I understand it, the recipe editor calculates all volumes (including preboil, postboil, and boil off rate) at room temperature, and the brew session log allows for temperature corrections to a degree. The formula used is linear, according to the documentation.

For those that like math...

Engineering toolbox has a chart of volumetric temperature expansion of water, which is what I based my formula on. Note that there's likely a weak relationship with gravity that is currently ignored as there's no data to know how it works. Engineering toolbox's data has a coefficient of 1.043841 at standard temperature and pressure, and shows a R^2 value of ~94.7 for linear functions, but 99.93% for a 2nd degree polynomial with greater accuracy as more terms are added.

3. ### Craigerrr Well-Known Member

Joined:
Mar 14, 2018
Messages:
4,700
6,899
Trophy Points:
113
#3
Thanks Priceless.
So, lets say that my recipe says preboil volume is 12.26 gallons. Is this calculating the theoretical room temperature wort volume (11.8) + 4% for thermal expansion?
Or should I be taking the 12.26 + 4% (12.75) to determine what actual hot volume I should have in my kettle preboil?
Mine is set at 4% by the way.

4. ### thunderwagn Well-Known Member

Joined:
Sep 5, 2015
Messages:
3,728
7,243
Trophy Points:
113
Gender:
Male
Location:
Loveland, CO
#4
You lost me at "I could be wrong"

5. ### Pricelessbrewing QA Software Tester Staff Member

Joined:
Jun 8, 2016
Messages:
764
502
Trophy Points:
93
Gender:
Male
#5
The hot preboil should be 12.75.

6. ### Nosybear Well-Known Member

Joined:
Jul 16, 2012
Messages:
9,378
6,608
Trophy Points:
113
Location:
Aurora, CO, USA
#6
My guess: 4% is likely accurate enough.

7. ### Craigerrr Well-Known Member

Joined:
Mar 14, 2018
Messages:
4,700
6,899
Trophy Points:
113
#7
Okay thanks priceless.

This raises another question though: What is the purpose of entering a value in the cooling shrinkage field in ones profile? What calculation, or function does this setting perform?

8. ### Pricelessbrewing QA Software Tester Staff Member

Joined:
Jun 8, 2016
Messages:
764
502
Trophy Points:
93
Gender:
Male
#8
It's used in the brew log entries in the various mash and boil entries under the volume section, click the checkbox for temperature correction and an input field temperature is displayed and an output for the adjusted volume.