Problems using my Refractometer - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > Equipment/Sanitation > Problems using my Refractometer

Reply
 
Thread Tools
Old 02-25-2013, 09:37 PM   #1
AndMan3030
Recipes 
 
Jun 2012
MPLS, MN
Posts: 244
Liked 30 Times on 27 Posts



I just acquired a refractometer for use in my All-Grain brewing productions. I would really like to utilize this tool for quickly checking the gravity of my runnings, and for Pre & Post boil gravity readings. During my last 3 brew sessions I have had stange results. My pre boil gravity will read higher than my post boil. This is not possible.

My refractometer is calibrated reading 0.00 with water.

During my last brew session (yesterday) it read 1.055 pre-boil. Post boil it read 1.048, which is what my hydrometer also read at 60 degrees F.

Whats going on ??

 
Reply With Quote
Old 02-25-2013, 09:42 PM   #2
azmark
Recipes 
 
Feb 2012
Posts: 122
Liked 7 Times on 6 Posts


I take it the brix are also going down instead of up? Gave both a chance to cool?

 
Reply With Quote
Old 02-25-2013, 10:57 PM   #3
AndMan3030
Recipes 
 
Jun 2012
MPLS, MN
Posts: 244
Liked 30 Times on 27 Posts


yeah i gave it plenty of time. plus 2-3 drops ought to cool pretty quick. Mine reads Specic Gravity and Brix.

 
Reply With Quote
Old 02-25-2013, 11:03 PM   #4
Brewsit
Recipes 
 
May 2011
San Antonio, TX
Posts: 203
Liked 20 Times on 18 Posts


My first thought is maybe there's some water in your post-boil sample, from after cleaning off the refractometer? Or maybe some residual water in the dropper? That could explain the original sample being higher (dry refractometer, dry dropper) and the second being lower (a wet dropper, wet lens or lens cover)? When I take samples I usually get as much water from cleaning out of the dropper and then cycle a few squirts to make sure that i've essentially washed the dropper, and make sure the lens is dry on all surfaces.

 
Reply With Quote
Old 02-26-2013, 12:40 AM   #5
Bobby_M
Vendor and Brewer
HBT_SPONSOR.png
 
Bobby_M's Avatar
Recipes 
 
Aug 2006
Whitehouse Station, NJ
Posts: 23,201
Liked 1658 Times on 1071 Posts


My guess is that your preboil sample was stratified and you picked from a more concentrated pocket.

 
Reply With Quote
Old 02-26-2013, 12:49 AM   #6
mikescooling
Recipes 
 
Jan 2012
Chicago, IL
Posts: 1,988
Liked 266 Times on 201 Posts


I like to use my pocket knife to get a drop or two. It's clean and dry and cool.

 
Reply With Quote
Old 02-26-2013, 12:50 AM   #7
Jipper
Recipes 
 
Dec 2008
Posts: 509
Liked 47 Times on 42 Posts


I'd agree with Bobby M that you probably pulled a preboil sample from a concentrated pocket / volume. Were you recirculating the mash? Did you pull the sample for preboil when the boil kettle was full, or while it was filling? If you pulled the reading while you were still filling your boil kettle, you most likely pulled a higher concentration, as the preboil gravity will dilute the further you are in your sparge.

 
Reply With Quote
Old 02-26-2013, 03:04 AM   #8
Komodo
Recipes 
 
May 2011
Bloomington, IN
Posts: 387
Liked 35 Times on 29 Posts


I've used mine with perfect results until this last session. It's really a time saver, but this time I got a lower post boil reading like the OP. I don't think temperature had anything to do with it. My guess was I got a pocket of lower gravity wort after I pitched my starter. It wasn't a ton, but the results were a real head scratcher. I started boil at 1.051 and ended around 1.059, but refractometer showed a 12.2?! (1.049)

Anyhow, I grabbed my hydrometer and measured. 1.060 and all was right in thhe world again.
__________________
Primary:
Resting: Tripel Six 11g, Witch Hunter Light - robust porter 11g
Drinking: EagleFire pale - homegrown Santiam dryhop

 
Reply With Quote
Old 02-27-2013, 04:58 PM   #9
AndMan3030
Recipes 
 
Jun 2012
MPLS, MN
Posts: 244
Liked 30 Times on 27 Posts


A pocket of lower Gravity?? that sounds a bit far fetched. I recirculated during the entire mash, and stirred my wort before taking the reading. I dip my temp probe in the wort and drip a couple drops on the glass. This has happened twice now, Pre-boil reading higer than the post boil. then the cooled hyderometer sample i take before pitching always matches the refractometer. HUH??

 
Reply With Quote
Old 02-27-2013, 05:55 PM   #10
NMG318
Recipes 
 
Aug 2011
Winchester, VA
Posts: 51
Liked 2 Times on 2 Posts


If you take a hot sample of wort (a couple of drops) any evaporation of that sample will cause the reading to be high. I usually put a 2 teaspoon sample in a cool glass for a few seconds until temp is down just a bit and then take a few drops from that sample. You have less evaporation and a better reading.

 
Reply With Quote


Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Regulator problems? Or Judo problems? Judochop Bottling/Kegging 11 05-13-2015 03:14 PM
Problems with the refractometer wfowlks Beginners Beer Brewing Forum 13 01-30-2013 04:32 PM
Refractometer Problems amazinglarry Equipment/Sanitation 3 05-16-2010 03:41 PM
Refractometer problems GNBrews General Techniques 8 12-30-2008 04:26 AM
Refractometer problems, maybe... 1234Alchemy Equipment/Sanitation 4 09-01-2007 04:27 AM


Forum Jump