When using the Beersmith or Promash refractometer tool is OG after boil or pre-boil - Home Brew Forums
Home Brew Forums > Home Brewing Beer > Brewing Software > When using the Beersmith or Promash refractometer tool is OG after boil or pre-boil

Reply
 
Thread Tools
Old 01-08-2011, 02:34 PM   #1
jetmac
HBT_SUPPORTER.png
 
jetmac's Avatar
Recipes 
 
Aug 2010
Mcdonough, Ga
Posts: 1,140
Liked 36 Times on 18 Posts



When entering the information into the refractometer tools is the OG number supposed to be from wort pre-boil or after boil?

If I enter the pre-boil gravity reading I took with my hydrometer of 1.049 and my first fermenting refractometer reading of 9.23 brix, the results line up with the fermenting hydrometer reading I took at the same time. >1.028<. But if I enter the post boil reading I took with my hydrometer of 1.062 the results in the refractometer tools are different. >1.021< That would mean my hydrometer reading during fermentation is wrong.

Which OG number should I use and what would cause my hydrometer to read incorrectly? Maybe CO2 floating the hydrometer?



 
Reply With Quote
Old 01-08-2011, 08:49 PM   #2
DirtyPolock
Recipes 
 
Jan 2010
Durham, NC
Posts: 296
Liked 3 Times on 3 Posts


I use promash and I think that it can be for either. There is an option for into kettle or into fermenter. At least that is what I think the options are...I'm at work now and can't double check my memory. I always do the into kettle so I know what my mash eff. is.

Did you temperature adjust your readings?


__________________
Primary #1: Cascade/Willamette APA
Primary #2: Air
Secondary #1: Belgian Dark Strong

Tap #1: Dubbel Red Balls
Tap #2: Honey Brown Ale
Tap #3: BierMuncher's Outer Limits IPA
Tap #4: Penn Dark Clone 1.0

Conditioning in Kegs: Pollinated porter

Bottled/Drinking: AHS Old School IPA; Apfelwein 1/22/10

Not just any keezer build...It's my keezer build | Don't fear the StarSan Foam, a math explanation

 
Reply With Quote
Old 01-08-2011, 08:51 PM   #3
Yooper
Ale's What Cures You!
HBT_ADMIN.png
 
Yooper's Avatar
Recipes 
 
Jun 2006
UP of Michigan, Winter Texan
Posts: 69,007
Liked 7600 Times on 5350 Posts


After fermentation begins, the presence of alcohol in the beer skews the readings of a refractometer. You use a refractometer to measure pre-fermenation gravity, either preboil or post boil.

There are software programs to account for the presence of alcohol in a refractometer reading that can adjust for it if you enter the OG, I believe, but they are not that accurate.
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006

 
Reply With Quote
Old 01-08-2011, 09:37 PM   #4
jetmac
HBT_SUPPORTER.png
 
jetmac's Avatar
Recipes 
 
Aug 2010
Mcdonough, Ga
Posts: 1,140
Liked 36 Times on 18 Posts


Quote:
Originally Posted by Yooper View Post
After fermentation begins, the presence of alcohol in the beer skews the readings of a refractometer. You use a refractometer to measure pre-fermenation gravity, either preboil or post boil.

There are software programs to account for the presence of alcohol in a refractometer reading that can adjust for it if you enter the OG, I believe, but they are not that accurate.
I understand that the reading could be perfectly wrong but I think it's pretty close because when I enter the pre-boil gravity reading I took with my hydrometer of 1.049 and my first "fermenting" refractometer reading of 9.23 brix, the results line up with the fermenting hydrometer reading I took at the same time. >1.028<. In other word the hydrometer and refractometer readings are the same. So then if the refractometer reading is skewed, the gravity is something else and it is skewing it to the exact gravity I get with the hydrometer. It's only when I enter my post boil/prefermenting gravity of 1.062, that I took using a hydrometer, into the refractrometer tool, that the gravity reading in the refractometer tool is different from my hydrometer reading.

 
Reply With Quote
Old 01-08-2011, 09:43 PM   #5
Yooper
Ale's What Cures You!
HBT_ADMIN.png
 
Yooper's Avatar
Recipes 
 
Jun 2006
UP of Michigan, Winter Texan
Posts: 69,007
Liked 7600 Times on 5350 Posts


Quote:
Originally Posted by jetmac View Post
I understand that the reading could be perfectly wrong but I think it's pretty close because when I enter the pre-boil gravity reading I took with my hydrometer of 1.049 and my first "fermenting" refractometer reading of 9.23 brix, the results line up with the fermenting hydrometer reading I took at the same time. >1.028<. In other word the hydrometer and refractometer readings are the same. So then if the refractometer reading is skewed, the gravity is something else and it is skewing it to the exact gravity I get with the hydrometer. It's only when I enter my post boil/prefermenting gravity of 1.062, that I took using a hydrometer, into the refractrometer tool, that the gravity reading in the refractometer tool is different from my hydrometer reading.
I don't understand what you're saying. The pre-fermentation refractometer reading and the OG reading from the hydrometer HAVE to match. That's how it's calibrated. There is a small adjustment factor (mine is 1.033) that you do in the "calibrate refractometer reading" in Beersmith that fixes all the readings for you from then on. After alcohol is in the solution, THEN it's when there are complicated formulas to adjust.

If the OG from the hydrometer and refractometer don't match, then it's either the calibration tool, the calibration of the hydrometer, or the calibration of the refractometer. Distilled water should be 0 with both the refractometer and hydrometer, so check that first!
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006

 
Reply With Quote
Old 01-08-2011, 10:25 PM   #6
jetmac
HBT_SUPPORTER.png
 
jetmac's Avatar
Recipes 
 
Aug 2010
Mcdonough, Ga
Posts: 1,140
Liked 36 Times on 18 Posts


Quote:
Originally Posted by Yooper View Post
I don't understand what you're saying. The pre-fermentation refractometer reading and the OG reading from the hydrometer HAVE to match. That's how it's calibrated. There is a small adjustment factor (mine is 1.033) that you do in the "calibrate refractometer reading" in Beersmith that fixes all the readings for you from then on. After alcohol is in the solution, THEN it's when there are complicated formulas to adjust.

If the OG from the hydrometer and refractometer don't match, then it's either the calibration tool, the calibration of the hydrometer, or the calibration of the refractometer. Distilled water should be 0 with both the refractometer and hydrometer, so check that first!
Maybe that's where things are skewed because I did not take a post-boil, pre-fermentation reading with the refractometer, just with the hydrometer.
Only during fermentation have I used the refractometer along with the hydrometer.

 
Reply With Quote
Old 05-02-2011, 04:10 AM   #7
mcondon
Recipes 
 
Jan 2010
Gainesville
Posts: 14


here is a site that you can use to use adjust for the presence of alcohol in your final gravity reading for the refractometer:http://seanterrill.com/2011/04/07/re...er-fg-results/


 
Reply With Quote
Old 05-02-2011, 03:45 PM   #8
Apoxbrew
Recipes 
 
Oct 2010
Medford, Oregon
Posts: 539
Liked 2 Times on 2 Posts


i didn't read the above responses (sorry... lol) but OG would always be post boil. beersmith does have a spot on the brew sheet for pre-boil gravity, but in terms of an actual OG that would be used to determine ABV, you'd always take that reading post boil (and if doing a partial boil, after you've added your post-boil water and mixed well).


__________________
BrewNano - Exploring Nano-Breweries, One Interview At A Time

On Tap - The Tunguska Event, Cream Ale
On Tap - Devastated Sky, CDA
On Tap - Fallow Fields, Autumn Ale
On Tap - East Creek Sour Wheat, Sour Wheat Ale
Fermenting - Nothing :(

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Beersmith boil off question skibb Brewing Software 1 11-11-2010 01:29 PM
Beersmith boil volume kshuler Brewing Software 2 07-20-2010 02:33 PM
Beersmith Boil Off thdewitt Brewing Software 28 12-09-2009 02:04 AM
Beersmith Boil Volume - IBU change Iowabeerguy Brewing Software 2 06-14-2009 06:21 PM
Beersmith - adjusting ingredient boil time nostalgia Brewing Software 3 03-20-2009 06:17 PM


Forum Jump