The Great Bottle Opener Giveaway

Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > Refractometer Reading

Reply
 
LinkBack Thread Tools
Old 11-27-2010, 01:17 AM   #1
pearlbeer
Feedback Score: 0 reviews
Recipes 
 
Join Date: Feb 2009
Location: Austin
Posts: 116
Liked 1 Times on 1 Posts
Likes Given: 1

Default Refractometer Reading

I just got a cool refractometer. It has ATC. In fact, it is this model:
http://www.austinhomebrew.com/produc...ducts_id=12574

I calibrated it.

My Porter's OG (Measured via hydometer) read 1.059 (14.5 Brix)

Just checked the FG with the new tool and measured 1.025 (6 Brix)

Using several online calculators, that is an adjust FG of like 1.003, which seems awfully dry. It doesn't taste that dry and I mashed at 153.

Need to double with my hydrometer..but am I doing something wrong in reading this thing?

__________________
pearlbeer is offline
 
Reply With Quote Quick reply to this message
Old 11-27-2010, 02:53 AM   #2
Paddle_Head
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2009
Location: Hudson Valley of NY
Posts: 112
Liked 1 Times on 1 Posts

Default

I don't have much to offer other than I had the same thing happen. When I checked with my hydrometer later it was at 1.012. Not sure if its the ETOH or the nature of the remaining sugars.

__________________
Paddle_Head is offline
 
Reply With Quote Quick reply to this message
Old 11-27-2010, 03:06 AM   #3
passedpawn
Moderator
HBT_MODERATOR.png
Feedback Score: 0 reviews
 
passedpawn's Avatar
Recipes 
 
Join Date: Apr 2009
Location: ☼ Clearwater, FL ☼
Posts: 18,089
Liked 2956 Times on 1874 Posts
Likes Given: 2496

Default

You cannot measure the gravity with a refractometer once there is alcohol. After adding yeast, you will need to rely on hydrometers.

Beersmith has correction tools that claim to allow you to do this, but believe me the resulting reading is not accurate. BYO magazine published all the formula to do this also, same result.

Sorry to be the bearer of bad news. I tried to make mine work for a long time, but I gave up (except for the pre-alcohol measurements).

__________________
try to earn what lovers own
passedpawn is offline
 
Reply With Quote Quick reply to this message
Old 11-27-2010, 03:27 AM   #4
Bearcat Brewmeister
Pour, Drink, Pee, Repeat
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Bearcat Brewmeister's Avatar
Recipes 
 
Join Date: Feb 2006
Location: Cincinnati, OH
Posts: 699
Liked 18 Times on 7 Posts

Default

Agreed. They are not accurate with alcohol present; however, they seem to be fairly good until you get near FG at which point they tend to be anywhere from correct to about 5 points low. I find you can use the refractometer to see when you are "close". As soon as it says you are at your expected FG, chances are you are within about 5 points or so and at that point, you switch over to your hydrometer and check. If you like to check gravity a lot and don't use a thief (and in that case, possibly dumping your test jar each time), it is a good way to save beer.

__________________
Kegged: Belgian Dark Strong, Robust Porter, Ryewine, Old Ale
Secondary:
Bock
Primary:
--
Next Up: Baltic Porter, Saison
Projects: Brutus Strut-stand, Freezer Conversion (Done), HERMS (Done), Lager Fermentation Mini-fridge Extension (Done)
Drinking: Great Lakes Edmund Fitzgerald, Fuller's 1845, Lakefront Fixed Gear, New Glarus Moon Man, Tröegs Troegenator
Bearcat Brewmeister is offline
 
Reply With Quote Quick reply to this message
Old 11-27-2010, 01:02 PM   #5
logdrum
Feedback Score: 1 reviews
Recipes 
 
Join Date: Aug 2010
Location: North Olmsted, Ohio
Posts: 766
Liked 34 Times on 33 Posts
Likes Given: 19

Default

What about this spreadsheet?

http://morebeer.com/learn_vids/vids_refract

__________________
logdrum is offline
 
Reply With Quote Quick reply to this message
Old 11-27-2010, 03:45 PM   #6
passedpawn
Moderator
HBT_MODERATOR.png
Feedback Score: 0 reviews
 
passedpawn's Avatar
Recipes 
 
Join Date: Apr 2009
Location: ☼ Clearwater, FL ☼
Posts: 18,089
Liked 2956 Times on 1874 Posts
Likes Given: 2496

Default

Quote:
Originally Posted by logdrum View Post
As far as I'm concerned, all the current methods/math of using a refractometer to measure fermenting beer are flawed.

This guy is on the right track to making it work, though. I'm waiting for the fallout from his data analysis before I continue doing this. Great work sean!

http://seanterrill.com/2010/06/11/re...final-gravity/
__________________
try to earn what lovers own
passedpawn is offline
 
Reply With Quote Quick reply to this message
Old 11-28-2010, 02:16 AM   #7
Bearcat Brewmeister
Pour, Drink, Pee, Repeat
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Bearcat Brewmeister's Avatar
Recipes 
 
Join Date: Feb 2006
Location: Cincinnati, OH
Posts: 699
Liked 18 Times on 7 Posts

Default

Quote:
Originally Posted by passedpawn View Post
As far as I'm concerned, all the current methods/math of using a refractometer to measure fermenting beer are flawed.

This guy is on the right track to making it work, though. I'm waiting for the fallout from his data analysis before I continue doing this. Great work sean!

http://seanterrill.com/2010/06/11/re...final-gravity/
I have seen his site as well. Problem is that he has been trying to do this with very limited data which is making his current result flawed. What he should be doing is a) take more readings per batch so that he has more data points from the same OG and can track the data curve, and b) ask others to contribute data. I hope he continues the work as well, but by posting his current results, I am wondering if that is in his plans.
__________________
Kegged: Belgian Dark Strong, Robust Porter, Ryewine, Old Ale
Secondary:
Bock
Primary:
--
Next Up: Baltic Porter, Saison
Projects: Brutus Strut-stand, Freezer Conversion (Done), HERMS (Done), Lager Fermentation Mini-fridge Extension (Done)
Drinking: Great Lakes Edmund Fitzgerald, Fuller's 1845, Lakefront Fixed Gear, New Glarus Moon Man, Tröegs Troegenator
Bearcat Brewmeister is offline
 
Reply With Quote Quick reply to this message
Old 11-28-2010, 05:22 AM   #8
GC89
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2009
Location: Spokane/Pullman
Posts: 175
Default

In my experience the morebeer spread sheet is pretty accurate, I have used it for several batches and they have all been within 2 points or so as far as I can tell. I still use a hydro for FG but its great for monitoring fermentation.

__________________

Black Harp Brewing

GC89 is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Implausible gravity reading on both hydrometer and refractometer NonServiam All Grain & Partial Mash Brewing 4 08-22-2010 04:48 PM
ebay refractometer not reading correctly CanadianNorth All Grain & Partial Mash Brewing 3 06-03-2010 05:42 PM
Refractometer reading 4 Brix on 3 week old wort TheCookieMonster All Grain & Partial Mash Brewing 9 03-01-2010 12:37 PM
Help with Refractometer asdtexas All Grain & Partial Mash Brewing 3 02-24-2010 10:59 PM
Which Refractometer Sherpa FE All Grain & Partial Mash Brewing 16 02-05-2008 04:03 PM