Happy HolidaySs Giveaway - Winners Re-Re-Drawn - 24 hours to Claim!

Get your HBT Growlers, Shirts and Membership before the Rush!


Home Brew Forums > Home Brewing Beer > General Techniques > Two hydrometers, two different readings..
Reply
 
LinkBack Thread Tools
Old 02-08-2013, 12:56 PM   #21
AVLbrewing
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2013
Posts: 173
Liked 17 Times on 8 Posts
Likes Given: 2

Default

Reminds me of a saying I once heard: "A man with one watch knows what time it is, a man with two is never quite sure."

I guess other than doing some two point calibration or buying a third and hoping there is agreement between two of them I'm not sure what else you could do.... Maybe buy a refractometer?

__________________
AVLbrewing is offline
 
Reply With Quote Quick reply to this message
Old 02-10-2013, 04:23 AM   #22
discokid2k
Feedback Score: 0 reviews
Recipes 
 
Join Date: May 2010
Location: san marcos, TX
Posts: 151
Likes Given: 3

Default

Quote:
Originally Posted by AVLbrewing View Post
Reminds me of a saying I once heard: "A man with one watch knows what time it is, a man with two is never quite sure."

I guess other than doing some two point calibration or buying a third and hoping there is agreement between two of them I'm not sure what else you could do.... Maybe buy a refractometer?
Ha! So true...the refractometer is on my list. I brewed tonight and I had better results doing a few different tricks. 1st, I re-crushed my grain using a bowl and mallet...just to be extra sure. Then I added my full sparge to my mash out to hopefully thin the sugars a little. Also cut nearly 1/2 gal out of calculation just to be sure I wouldn't pull too much water (also added a little over 1qt to cool my mash before starting timer).

Old hydrometer read 1.040 and new read 1.044. Temp correction (@77*) gives me a 1.046 and only -7pts from my expected OG of 1.053. Brewhouse efficiency today rose by 10%, up to an 85%. Not to shabby
__________________
discokid2k is offline
 
Reply With Quote Quick reply to this message
Old 02-10-2013, 09:08 AM   #23
TheZer
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2010
Location: Florida
Posts: 155
Liked 29 Times on 9 Posts
Likes Given: 1

Default

Quote:
Originally Posted by discokid2k View Post
That is actually not a bad idea. I have tested both hydro's in water and one is spot on, the other is -.04pts. Testing in a solution say, four or five times each and averaging the results is a great test. I will give that a shot.
A 0.04 pt difference in water and a 0.07 difference in wort means the slopes of the two hydrometers are not the same. Take a third reading after adding a teaspoon of sugar to your wort sample, plot the results on a graph, then throw away the hydrometer on the left.
__________________
TheZer is offline
 
Reply With Quote Quick reply to this message
Old 02-10-2013, 10:59 PM   #24
MichaelBrock
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
MichaelBrock's Avatar
Recipes 
 
Join Date: Jun 2011
Location: Alachua, FL
Posts: 485
Liked 30 Times on 25 Posts
Likes Given: 38

Default

Quote:
Originally Posted by BargainFittings View Post
One of the scales is printed wrong. That would be the only way they would be different at start and finish barring user error reading the scale.
I have been thinking about this and I'm not certain that it is true. The variation of buoyancy with density is linear. The relationship between the density of the wort and the vertical movement of the hydrometer is not linear. As the hydrometer sinks further with lower gravity more of the stem is under the surface and so the buoyancy force goes up. Is the diameter of the stem tapered to counter-act this or is the scale non-linear? I have no idea. If it is isn't, then I would expect the hydrometers to be more accurate at higher gravities when less of the stem is under the surface. I tried a two-point calibration which bore this out. Of course it is entirely possible I flubbed something up.
__________________
MichaelBrock 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
Two Hydrometers - Two Readings FensterBos Beginners Beer Brewing Forum 1 09-16-2012 06:46 PM
brew day gravity readings and next day readings rustynails223 General Beer Discussion 3 03-05-2012 04:14 PM
hydrometers how many drunde77 Beginners Beer Brewing Forum 23 02-15-2012 01:17 AM
Hydrometers? We don't need no stinking hydrometers! - When a homebrew goes south... AlterCow Beginners Beer Brewing Forum 17 03-07-2010 10:42 PM



Newest Threads

LATEST SPONSOR DEALS