The numbers don't add up again...WHY?!? - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > General Techniques > The numbers don't add up again...WHY?!?

Reply
 
Thread Tools
Old 04-26-2012, 04:20 AM   #1
klnosaj
HBT_LIFETIMESUPPORTER.png
 
klnosaj's Avatar
Recipes 
 
Sep 2011
Berkeley, CA
Posts: 436
Liked 9 Times on 8 Posts



The past two beers I've made have had the same problem. My pre-boil gravity is spot on. My pre-boil water volume is spot on. My post-boil water volume is spot on. Yet my post-boil into-the-fermenter original gravity is low. Isn't that kind of impossible?

Here are the details today:

------------------estimated -------measured

pre-boil SG---------1.040------------1.040

pre-boil H2O vol----7.0 gal-----------7.0 gal

post boil SG--------1.049------------1.043

post-boil H2O vol---5.25 gal----------5.25 gal

all estimates provided by beersmith 2.0, all measurements cross checked between hydrometer and refractometer, post-boil SG taken form two independent samples.


What is going on? I'm going crazy over this!

 
Reply With Quote
Old 04-26-2012, 04:22 AM   #2
bottlebomber
 
bottlebomber's Avatar
Recipes 
 
Apr 2011
Ukiah, CA
Posts: 14,342
Liked 2737 Times on 2112 Posts


It's the trub dude

 
Reply With Quote
Old 04-26-2012, 04:56 AM   #3
klnosaj
HBT_LIFETIMESUPPORTER.png
 
klnosaj's Avatar
Recipes 
 
Sep 2011
Berkeley, CA
Posts: 436
Liked 9 Times on 8 Posts


Quote:
Originally Posted by bottlebomber View Post
It's the trub dude
I thought of that. So I measured it. It's 2.5 quarts, and that includes all the solid matter. That means my total post-boil volume was 5.875 gallons. What it should've been, according to the software, is 5.82 gals. That's within the margin of measurement error, right? That's about 6 oz of water and, as I said, it includes the entire volume of solid hop debris. I think it's something else.

 
Reply With Quote
Old 04-26-2012, 05:11 AM   #4
AZ_IPA
PKU
HBT_LIFETIMESUPPORTER.png
 
AZ_IPA's Avatar
Recipes 
 
Jun 2008
The Cold Part of AZ
Posts: 53,591
Liked 9078 Times on 7226 Posts


volume differences based on different temperatures?

 
Reply With Quote
Old 04-26-2012, 05:56 AM   #5
klnosaj
HBT_LIFETIMESUPPORTER.png
 
klnosaj's Avatar
Recipes 
 
Sep 2011
Berkeley, CA
Posts: 436
Liked 9 Times on 8 Posts


Quote:
Originally Posted by AZ_IPA View Post
volume differences based on different temperatures?
I think BeerSmith takes care of that. Good suggestion, though. I guess it HAS to be a measurement error but it seems unlikely that I'd make the exact same error measuring two or three different batches over the course of a month. Nothing in my equipment has changed. I feel like I'm banging my head against a wall here and Lord knows I've already been doing that enough lately. If I could figure out where or what the measurement error is I could correct it but I have no idea why I'm off.

 
Reply With Quote
Old 04-26-2012, 08:11 AM   #6
klnosaj
HBT_LIFETIMESUPPORTER.png
 
klnosaj's Avatar
Recipes 
 
Sep 2011
Berkeley, CA
Posts: 436
Liked 9 Times on 8 Posts


I'm wondering this: does wort boil off at the same rate as water?

 
Reply With Quote
Old 04-26-2012, 01:58 PM   #7
bottlebomber
 
bottlebomber's Avatar
Recipes 
 
Apr 2011
Ukiah, CA
Posts: 14,342
Liked 2737 Times on 2112 Posts


Quote:
Originally Posted by klnosaj
I'm wondering this: does wort boil off at the same rate as water?
I would say it boils off faster. The more dissolved solids are in water, the lower the boiling point.

 
Reply With Quote
Old 04-26-2012, 03:10 PM   #8
Psych
 
Psych's Avatar
Recipes 
 
Mar 2011
Kelowna, BC
Posts: 780
Liked 37 Times on 34 Posts


You're definitely adjusting your hydro readings (using beersmith's lovely temp adjustment tool) to account for temperature? Hydro readings should all be adjusted to something like 62f or something.

 
Reply With Quote
Old 04-26-2012, 03:48 PM   #9
helibrewer
HBT_SUPPORTER.png
 
helibrewer's Avatar
Recipes 
 
Nov 2011
Santa Rosa, CA
Posts: 3,808
Liked 324 Times on 274 Posts


Is this with extract recipes? Any grains? All grain?
__________________
Something is always fermenting....
"It's Bahl Hornin'"

Primary:
Kegged: Bourbon Barrel Imperial Stout
On Deck: German Lager

 
Reply With Quote
Old 04-26-2012, 04:37 PM   #10
AZ_IPA
PKU
HBT_LIFETIMESUPPORTER.png
 
AZ_IPA's Avatar
Recipes 
 
Jun 2008
The Cold Part of AZ
Posts: 53,591
Liked 9078 Times on 7226 Posts


If your volume measurements and thermometer are accurate, your measured post-boil OG is, shall I say, unpossible.

No way you can boil off nearly 1.75 gallons and only rise 3 gravity points.

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
The Numbers Don't Add Up Xiren General Techniques 15 10-13-2009 12:35 AM
What water numbers do I want?? mangine77 General Techniques 1 11-24-2008 02:36 PM
Yeah, I've got numbers...but what does it all really MEAN? Deacon1856 General Techniques 8 10-01-2008 02:56 AM
rating numbers mikemilburn General Techniques 1 05-14-2007 01:46 AM


Forum Jump