Calibrating my Hydrometer - Home Brew Forums
Home Brew Forums > Home Brewing Beer > Beginners Beer Brewing Forum > Calibrating my Hydrometer

Reply
 
Thread Tools
Old 04-02-2009, 02:04 PM   #1
TexasSpartan
Recipes 
 
Jan 2009
Dallas, TX
Posts: 752
Liked 23 Times on 19 Posts



I'm just an extract brewer, and my OG and FG readings are always a little off. Never enough that I feel the need to ask if I've ruined my beer, but they're not what they should be.

I checked my hydrometer, and it says it is calibrated for 60 degrees. Look, I live in Texas. My house is never 60 degrees. The kitchen is usually closer to 70-75 when I'm brewing. And more importantly, my beer is usually at 70 or so when I'm pitching the yeast or taking a reading for the FG. So how do I adjust for temperature?

My thought was this, and please correct me if I'm wrong. Get some distilled water and let it warm up to room temperature. Drop the hydrometer and see what it reads. At 60 degrees it should read 1.000, correct? So if it read 0.998 (for example) at 70 degrees, I would add 0.002 to whatever reading I got.

Am I on the right track, or way off base?
__________________
Dead Felon Brewing

 
Reply With Quote
Old 04-02-2009, 02:07 PM   #2
Nugu
Recipes 
 
Mar 2009
Nebraska
Posts: 145

There's an equation you can plug it into I think. Unfortunately I don't know it (undoubtedly someone will enlighten us though) but ya that would work assuming you always took the reading at 70F.

I generally leave close enough as close enough. (we're talking it being off at most like .002
__________________
I like beer, do you?

 
Reply With Quote
Old 04-02-2009, 02:26 PM   #3
david_42
 
david_42's Avatar
Recipes 
 
Oct 2005
Willamina & Oak Grove, Oregon, USA
Posts: 25,593
Liked 151 Times on 142 Posts


The correction varies with temperature and gravity, but the simplest thing it to check your hydrometer a 60F, then at 70F. Shouldn't be more than 0.002 delta.
__________________
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"

"I would like to die on Mars, just not on impact." Elon Musk

 
Reply With Quote
Old 04-02-2009, 02:59 PM   #4
McKBrew
 
McKBrew's Avatar
Recipes 
 
Oct 2006
Hayden, Idaho
Posts: 8,204
Liked 35 Times on 30 Posts


There are several free applications on the internet that will do the conversion for you.
__________________
Make Beer, Not War.

 
Reply With Quote
Old 04-02-2009, 05:30 PM   #5
eljefebrewing
Recipes 
 
Mar 2009
Posts: 95
Liked 1 Times on 1 Posts


Look in Appendix I (I think) on howtobrew.com. Nice table there.

 
Reply With Quote
Old 04-02-2009, 06:04 PM   #6
bull8042
I like 'em shaved
HBT_LIFETIMESUPPORTER.png
 
bull8042's Avatar
Recipes 
 
Jul 2008
Fort Mill, SC
Posts: 10,263
Liked 450 Times on 447 Posts


BeerSmith also has a correction tool that requires you to enter the temp of the sample and the reading and it will give the corrected value.
__________________
"I brew with a water cooler and some part from the toilet." - JohnnyO

"I do gravity feed the last gallon or two through my Therminator, but I expect you could suck start a Volkswagen before you could suck start one of these. - GilaMinumBeer

"..... Bull was right." - TXCurtis

 
Reply With Quote
Old 04-02-2009, 06:46 PM   #7
shawnbou
Zyme Lord
HBT_LIFETIMESUPPORTER.png
 
shawnbou's Avatar
Recipes 
 
Mar 2009
Austin, Texas
Posts: 543
Liked 23 Times on 21 Posts


I'm very new to this myself, but as a fellow Texan I can relate to your problems getting your house down to 60F!

My hydrometer reads accurately at 68F, so I think it may just vary from one hydrometer to another. Mine did come with a handy chart, though, for corrections due to temperature. I add .001 for every 9 degrees over 68, and subtract .001 for every 9 degrees under 68 ... the concept here being that warmer liquids are thinner and therefore will have a higher SG when they get to room temp, and vice versa.

Hope that helps. It sounds like you're on the right track.

 
Reply With Quote
Old 04-02-2009, 09:15 PM   #8
steelerguy
Recipes 
 
Apr 2008
Stony Brook, NY
Posts: 486
Liked 11 Times on 7 Posts


Here ya go:

The Beer Recipator - Hydrometer Correction

(This is assuming your hydrometer reads correctly at the calibrated temp)

 
Reply With Quote
Old 04-03-2009, 03:02 AM   #9
TexasSpartan
Recipes 
 
Jan 2009
Dallas, TX
Posts: 752
Liked 23 Times on 19 Posts


Quote:
Originally Posted by steelerguy View Post
Here ya go:

The Beer Recipator - Hydrometer Correction

(This is assuming your hydrometer reads correctly at the calibrated temp)
Thanks
__________________
Dead Felon Brewing

 
Reply With Quote


Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Calibrating Hydrometer in tap water? mkorpal General Techniques 4 06-24-2009 10:31 PM
Calibrating brew pot... tireater Equipment/Sanitation 15 04-26-2009 07:56 AM
Calibrating Brewing Thermometer BrewCF Beginners Beer Brewing Forum 2 03-11-2009 08:16 PM
calibrating my keggle DrugCoder Equipment/Sanitation 4 01-24-2009 11:26 PM
Calibrating bimetallic thermometers AiredAle Equipment/Sanitation 4 01-16-2008 01:10 AM


Forum Jump