Using a Refractometer - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > General Beer Discussion > Using a Refractometer

Reply
 
Thread Tools
Old 12-30-2012, 03:57 AM   #1
Jakeorjacob
Recipes 
 
Dec 2012
Ypsilanti, Michigan
Posts: 17


Bought a refractometer a couple months ago and I'm really enjoying using it to measure pre-boil and OG before adding yeast. However, I was very confused to make a couple batches that I thought were under-attenuated because I kept using the refractometer to find the Brix (and then gravity) of the fermenting wort. I had no idea that the calculation for determining the gravity of fermenting wort is a) different and b) complicated.

So, my two questions:

1. What is the calculation?
2. What websites or apps do people use to find a reliable gravity using the Brix and OG of fermenting wort? I've seen a couple but am getting slightly different numbers from each one.

(I understand that I could just measure gravity using a hydrometer, but I am brewing one gallon batches (at least for a little while longer) and I hate to waste that much wort just to check the gravity. The refractometer works so much better and if I can find a reliable way to calculate, I will be a happy camper!)

 
Reply With Quote
Old 12-30-2012, 04:03 AM   #2
Satisfaction
Recipes 
 
Oct 2011
Brunswick, ME
Posts: 391
Liked 38 Times on 26 Posts


Good timing, just went through this very topic in another post.

The website to use seems to be..

http://seanterrill.com/2012/01/06/re...er-calculator/


Here is the post we were discussing the drawbacks of using a refractometer for calculating beer OG and FG.

http://www.homebrewtalk.com/f14/who-...38/index3.html

 
Reply With Quote
Old 12-30-2012, 04:22 AM   #3
Jakeorjacob
Recipes 
 
Dec 2012
Ypsilanti, Michigan
Posts: 17

Sweet, thanks!

 
Reply With Quote
Old 12-30-2012, 04:54 AM   #4
Sock
Recipes 
 
Nov 2011
Vancouver, B.C.
Posts: 58
Liked 11 Times on 7 Posts


Just drop the whole hydrometer into the batch instead of taking a sample. Make sure its really clean....!

 
Reply With Quote
Old 12-30-2012, 05:01 AM   #5
Dan
HBT_LIFETIMESUPPORTER.png
 
Dan's Avatar
Recipes 
 
Oct 2010
Makakilo, Hawaii
Posts: 7,040
Liked 2176 Times on 1362 Posts


I had my refractometer doubts for awhile too, but after comparing a few batches' final gravity with a hydrometer and refractometer using a correction table I've found a refractometer pretty accurate. The two might not agree completely, like 0.003 off. I can live with that and have more beer in the end.

 
Reply With Quote
Old 12-30-2012, 05:53 AM   #6
Satisfaction
Recipes 
 
Oct 2011
Brunswick, ME
Posts: 391
Liked 38 Times on 26 Posts


Quote:
Originally Posted by Dan View Post
I had my refractometer doubts for awhile too, but after comparing a few batches' final gravity with a hydrometer and refractometer using a correction table I've found a refractometer pretty accurate. The two might not agree completely, like 0.003 off. I can live with that and have more beer in the end.
My same conclusion as well.. Had doubts, confirmed those doubts, and the significance of those differences are.. well insignificant in my opinion. Pick one and stick with it.

Dan Likes This 
Reply With Quote
Old 12-30-2012, 01:05 PM   #7
Jakeorjacob
Recipes 
 
Dec 2012
Ypsilanti, Michigan
Posts: 17

Nice. I like using the refractometer way better, and even if I was making ten gallons, the amount of liquid lost to a hydrometer would still irk me. It's like half a beer! I have no need to "sample" that much beer every time I check the gravity - the few extra drops left over from the refractometer is usually enough to get an idea on how the beer is doing.

 
Reply With Quote
Old 12-30-2012, 01:22 PM   #8
Epimetheus
Recipes 
 
Oct 2012
Amherst, MA
Posts: 793
Liked 98 Times on 82 Posts


Another post about refractometer accuracy for FG. I'm getting a refractometer anyway.
http://www.homebrewtalk.com/f11/refr...d-beer-333712/
... and from that thread
Quote:
Originally Posted by erikpete18 View Post
Personally, I don't mind using the hydrometer, because its a lot harder to taste test my refractometer samples!
Sock, great idea to put the hydrometer in the wort bucket - if you can read it.
__________________
Whether beer is made in waders or in a toilet tank, as long as it is fun and the brewer likes how it tastes, who cares how it is brewed?
- VladOfTrub

Add your water analysis to the water report map! Instructions on this thread

 
Reply With Quote
Old 12-30-2012, 01:35 PM   #9
Frige
Recipes 
 
Sep 2012
Houston, Texas
Posts: 554
Liked 68 Times on 48 Posts


I have been just dropping mine into the wort bucket for a while now. Much easier. Refractometer is next on my goodie list.

 
Reply With Quote
Old 12-30-2012, 01:53 PM   #10
Yooper
Ale's What Cures You!
HBT_ADMIN.png
 
Yooper's Avatar
Recipes 
 
Jun 2006
UP of Michigan, Winter Texan
Posts: 69,229
Liked 7721 Times on 5424 Posts


I always use a refractometer for prefermentation readings for my beer and wine. Then, for the FG, I use a hydrometer.

I've never had my refractometer be accurate, even with corrections, with a finished beer or wine. Ever.

But I love my refractometer, and I use it several times on each brewday.

I use my hydrometer on the day I package the beer. It doesn't take much beer for a sample- I think it's 3 ounces. I just drink that sample. I can "afford" to give up three ounces of beer with a FG reading to ensure I don't get bottle bombs. It's worth it!
__________________
Broken Leg Brewery
Giving beer a leg to stand on since 2006

 
Reply With Quote


Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Refractometer markephraim Beginners Beer Brewing Forum 6 02-27-2011 02:53 AM
Refractometer jwible204 All Grain & Partial Mash Brewing 21 01-04-2011 12:16 AM
Refractometer chode720 Equipment/Sanitation 10 12-26-2009 09:09 PM
Refractometer!! stephelton General Beer Discussion 14 03-08-2009 04:43 AM
Refractometer Help....? HOP-HEAD Equipment/Sanitation 4 03-02-2009 04:52 AM


Forum Jump