Stillraining
Well-Known Member
OK we brewed last Sunday and did the experiment that I promised in another thread. I thought others may find this information useful so I wanted to make it easier to find on its own if it was searched for..
The challenge was to Myth Bust rather Hot Corrected Hydrometer readings were so inaccurate as to render them useless or untrustworthy...here are the results.
IR measurements........................Corrected to 60.........Actual 60 readings
1st running's......1.066 @ 113...............1.077...................1.080
2nd running's.... 1.020 @ 129................1.031..................1.030
3rd running s.....1.004 @ 129.................1.016.................1.015
Pre-Boil............ 1.030 @ 116................1.039.................1.040
Post boil............1.035 @ 127................1.047.................1.048
So there are some slight inconsistencies and its not linear... The higher gravity wort seemed to show the greatest variation. A .003 differential in the corrected vs calibrated readings does translate into a fair discrepancy at about a 0.4% ABV so if your brewing big beers this is a significant if your a Need to Know kind of person. However a .001 differential at a higher frequency brewed beer around the .045 to .055 range translates into around a 0.13 % ABV difference. This still wont be close enough for the Analytical type brewer, but personally for a non meticulous guy like me I will never wait for samples to cool ever again. IR readings hot and later corrected are Close enough for me.
Did we succeed in the myth bust...not really, there is a respectable difference...But I believe with enough experiments one would dial in exactly what that difference would be on a repeatable consistent basis over a spectrum of Gravity's and temperatures to render it inconsequential. One take-a-way is the hot readings were pretty much all consistently low, so your actually getting slightly better outcomes then the corrected measured numbers tell you....something comforting anyway. The bottom line is that they are totally usable and trustworthy to a point.
For me the lazy brewer, the speed and simplicity at which I can obtain my readings far out weighs the time and hassle it takes to cool to a specific degree too get dead on numbers..YMMV
OH... one more take-a-way..My last 3.8% Lawn Mower beer is actually a 3.9% No wonder my lines were not as straight last mow... I'm more polluted then I thought ...
Hope you found this at least interesting.
The challenge was to Myth Bust rather Hot Corrected Hydrometer readings were so inaccurate as to render them useless or untrustworthy...here are the results.
IR measurements........................Corrected to 60.........Actual 60 readings
1st running's......1.066 @ 113...............1.077...................1.080
2nd running's.... 1.020 @ 129................1.031..................1.030
3rd running s.....1.004 @ 129.................1.016.................1.015
Pre-Boil............ 1.030 @ 116................1.039.................1.040
Post boil............1.035 @ 127................1.047.................1.048
So there are some slight inconsistencies and its not linear... The higher gravity wort seemed to show the greatest variation. A .003 differential in the corrected vs calibrated readings does translate into a fair discrepancy at about a 0.4% ABV so if your brewing big beers this is a significant if your a Need to Know kind of person. However a .001 differential at a higher frequency brewed beer around the .045 to .055 range translates into around a 0.13 % ABV difference. This still wont be close enough for the Analytical type brewer, but personally for a non meticulous guy like me I will never wait for samples to cool ever again. IR readings hot and later corrected are Close enough for me.
Did we succeed in the myth bust...not really, there is a respectable difference...But I believe with enough experiments one would dial in exactly what that difference would be on a repeatable consistent basis over a spectrum of Gravity's and temperatures to render it inconsequential. One take-a-way is the hot readings were pretty much all consistently low, so your actually getting slightly better outcomes then the corrected measured numbers tell you....something comforting anyway. The bottom line is that they are totally usable and trustworthy to a point.
For me the lazy brewer, the speed and simplicity at which I can obtain my readings far out weighs the time and hassle it takes to cool to a specific degree too get dead on numbers..YMMV
OH... one more take-a-way..My last 3.8% Lawn Mower beer is actually a 3.9% No wonder my lines were not as straight last mow... I'm more polluted then I thought ...
Hope you found this at least interesting.
