New Giveaway - Wort Monster Conical Fermenter!

Home Brew Forums > Home Brewing Beer > Equipment/Sanitation > On refractometer readings...




Reply
 
LinkBack Thread Tools Display Modes
Old 09-19-2011, 10:50 AM   #1
bushwilliams
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2011
Location: Little Rock, AR
Posts: 20
Default On refractometer readings...

Okay, so here is the question, likely answer is simple. I take a reading, say of my OG. The reading may be 1055 however if I set down the refractometer and forget about it for an hour it may have crept up to 1065. Is this normal? My gut (and expected numbers) tells me the initial 1055 is the correct choice, but then why would it float like that? Is the ATC (I have ATC) just getting wonky as the bead sits on the glass? Your thoughts are as always, appreciated.

Note (ATC Refractometer, calibrated with RO/DI to 0.00 on each brew day)samples in question are pulled from 150-170 degrees and read immediately. When allowed to cool they are increasing.



__________________

I'll drink to your leg...

bushwilliams is offline
 
Reply With Quote Quick reply to this message
Old 09-19-2011, 11:28 AM   #2
fxdrider
Slightly Better than Mediocre Brewer
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
fxdrider's Avatar
Recipes 
 
Join Date: Jul 2011
Location: Stafford, VA
Posts: 89
Liked 6 Times on 5 Posts
Likes Given: 11

Default

I'm just guessing here, but maybe evaporation of some liquid may leave a slightly denser wort sample. Again, just a guess - I may be WAY off.



__________________
O'Zapft Ist!
Ein Prosit, ein Prosit
Der Gemütlichkeit!
Ein Prosit, ein Prosit
Der Gemütlichkeit!


Trinken Sie das Bier, das hat Sie gebraut!
fxdrider is offline
 
Reply With Quote Quick reply to this message
Old 09-19-2011, 01:24 PM   #3
BargainFittings
Vendor
HBT_SPONSOR.png
Feedback Score: 1 reviews
 
BargainFittings's Avatar
Recipes 
 
Join Date: Nov 2008
Location: Allen TX
Posts: 1,835
Liked 37 Times on 32 Posts
Likes Given: 3

Default

I too would guess evaporation is the culprit

BargainFittings is offline
 
Reply With Quote Quick reply to this message
Old 09-19-2011, 02:27 PM   #4
bushwilliams
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2011
Location: Little Rock, AR
Posts: 20
Default

Hmm that makes a little too much sense now that you lay it out there. This is good, my gut told me those initial numbers were right (especially since they are usually the ones I am trying so hard to hit) thanks for your input, its great to have faith in my gear.

__________________

I'll drink to your leg...

bushwilliams is offline
 
Reply With Quote Quick reply to this message
Old 09-19-2011, 06:48 PM   #5
Guess42
Feedback Score: 0 reviews
Recipes 
 
Join Date: Dec 2010
Location: Rochester, NY
Posts: 163
Liked 4 Times on 4 Posts

Default

Might also check the instructions. I believe most ATC's on refractometers have a range where the ATC works.

__________________
Guess42 is offline
 
Reply With Quote Quick reply to this message
Old 11-20-2011, 01:56 AM   #6
C-Rider
Senior Member
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
C-Rider's Avatar
Recipes 
 
Join Date: Feb 2011
Location: Wai, Hawaii
Posts: 2,447
Liked 112 Times on 97 Posts
Likes Given: 260

Default

I just did a brew the other day. Took OG reading right away w/hot wort and got a readding of something like 14 brix. Waiting about 1 min I get a reading about 20 brix. Never thought about evaporation. I've been using the higher number because I figure that the hot wort has to cool a bit. I'll never have wort at 60* which I understand is what the meters are calibrated for.

__________________

Kaiser Ridge Brewing
-------------------------
Fermenting: OldGlory (Am Stout)
Cold Crashing: Pale Ale
Conditioning: GermanImperialStout
Bottled in the refer: NorthernBrownAle (GF)
Bottled in the refer: German IPA
Bottled in the refer: KonaCoffeeDryStout
Bottled in the refer: Düsseldorf Altbier

C-Rider is offline
 
Reply With Quote Quick reply to this message
Old 11-20-2011, 01:15 PM   #7
RM-MN
HBT_SUPPORTER.png
Feedback Score: 1 reviews
Recipes 
 
Join Date: Nov 2010
Location: Solway, MN
Posts: 6,121
Liked 639 Times on 535 Posts
Likes Given: 185

Default

Quote:
Originally Posted by C-Rider View Post
I just did a brew the other day. Took OG reading right away w/hot wort and got a readding of something like 14 brix. Waiting about 1 min I get a reading about 20 brix. Never thought about evaporation. I've been using the higher number because I figure that the hot wort has to cool a bit. I'll never have wort at 60* which I understand is what the meters are calibrated for.
What? Don't you have refrigeration in Hawaii? Take a small sample in a metal measuring cup and set it on a cube of ice or in a small container of ice water. You can cool it quite quickly that way. Be sure to have a thermometer so you can take it off the ice when it gets to 60.
__________________
RM-MN is online now
 
Reply With Quote Quick reply to this message
Old 11-20-2011, 01:28 PM   #8
bpolivka
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2011
Location: Evanston, IL
Posts: 14
Default

Also, ATC compensates for the temperature of the refractometer, not the sample. You don't need to wait long for the few necessary drops to cool, but you will get a low reading if you try to measure a hot sample right away.

__________________
bpolivka is offline
 
Reply With Quote Quick reply to this message
Old 11-21-2011, 12:51 AM   #9
stlbeer
Senior Member
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
stlbeer's Avatar
Recipes 
 
Join Date: Jan 2008
Location: Fenton, MO
Posts: 842
Liked 31 Times on 30 Posts
Likes Given: 71

Default

Quote:
Originally Posted by bpolivka View Post
Also, ATC compensates for the temperature of the refractometer, not the sample. You don't need to wait long for the few necessary drops to cool, but you will get a low reading if you try to measure a hot sample right away.
Very interesting! I thought ATC was for the sample, not the temp of the refractometer. How long would it take for a drop of wort to cool? I'm guessing not too long.
__________________
stlbeer is offline
 
Reply With Quote Quick reply to this message
Old 11-21-2011, 12:59 AM   #10
kh54s10
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2011
Location: Tiverton, Rhode Island
Posts: 5,942
Liked 482 Times on 408 Posts
Likes Given: 129

Default

Quote:
Originally Posted by bpolivka View Post
Also, ATC compensates for the temperature of the refractometer, not the sample. You don't need to wait long for the few necessary drops to cool, but you will get a low reading if you try to measure a hot sample right away.
Really? I take a sample and look at it then write down the gravity, Then I look again and write down the brix. During this time nothing changes. I wipe the lens clean and take another sample. I have not seen any changes. I have even waited a few minutes and looked again and it is still the same. I don't know what I am doing wrong/right.


__________________
kh54s10 is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Refractometer and Hydrometer readings off BeezBrew Equipment/Sanitation 7 08-08-2011 11:09 PM
Varying OG Readings from a Refractometer wendelgee2 Equipment/Sanitation 2 11-29-2010 05:57 PM
Confused about recent refractometer readings pretzelb Equipment/Sanitation 21 03-01-2010 03:09 AM
Pipette Sanitation for Refractometer Readings hafmpty Equipment/Sanitation 3 02-24-2010 05:47 AM
Refractometer akamatt Equipment/Sanitation 15 08-08-2008 08:51 PM