Spike Brewing 12.5 Conical Fermenter Giveaway - Enter Now!

Home Brew Forums > Home Brewing Beer > Beginners Beer Brewing Forum > Gravity questions and clarification please

Reply
 
LinkBack Thread Tools
Old 11-08-2012, 09:48 PM   #1
Frenchtom
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 9
Default Gravity questions and clarification please

Hello – I am getting back into brewing after a 10 year hiatus. Things have changed a little bit, mostly terms and technology, and I am a little confused in the area of gravity readings.

Please review the below list and kindly comment/correct on anything I have wrong

Original gravity is the gravity of the wort after mashing. Hitting this number tells the brewer when mashing is complete, usually 30 minutes to an hour. The reading is taken from the first debris-clear runnings from the mash vessel using 60F wort.

Final gravity is the gravity of the beer after fermenting. The reading is taken from debris-clear beer from the fermentation vessel at 60F. Hitting the target number means you are done fermenting.

Here is where I get really confused:

The gravity on the final runnings of complete sparging is called ??? Hitting 1.008 gravity at 60F means sparging is complete. Or, some brewers merely sparge until the wort runs clear, right?

The gravity of the blended wort (all sparge runnings mixed together) before boiling is called ??? Where should this number be in relation to the original gravity? This is also measured at 60F.

The gravity of the blended wort (all sparge runnings mixed together) after boiling is called ??? Where should this number be in relation to the original gravity? This is also measured at 60F

Thanks!

Tom B.

__________________
Frenchtom is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2012, 10:00 PM   #2
tally350z
HBT_SUPPORTER.png
Feedback Score: 3 reviews
 
tally350z's Avatar
Recipes 
 
Join Date: May 2011
Location: Tallahassee, FL
Posts: 1,162
Liked 75 Times on 63 Posts
Likes Given: 1

Default

Normally you don't want to gather any sparge running's if the reading is below 1.010. I only continue to sparge until I hit my pre-boil volume.
You have the pre-boil gravity reading which is what you start your boil with after you hit your total pre-boil volumes. This tells you how the process is going, and if you had good extraction/conversion. Lets say your target OG(post-boil) is 1.060 and your pre-boil is 1.060. That means you had better efficiency than you calculated your recipe for. Make adjustments next time to compensate for the higher efficiency.

Then you have your Original Gravity which is after you boil and when the wort is put in the fermentor.

__________________
Toasting Tortoise Brewery
Primary - Smoked Belgium
Secondary - SOUR TORTOISE
Kegged
- Burton IPA, Munich Lager, Cream Ale
Bottled - Muscadine Port, Imperial Stout

North Florida Brewers League
tally350z is online now
 
Reply With Quote Quick reply to this message
Old 11-08-2012, 10:00 PM   #3
tre9er
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2012
Location: Lincoln, NE
Posts: 4,372
Liked 232 Times on 196 Posts
Likes Given: 35

Default

Quote:
Originally Posted by Frenchtom View Post
Hello – I am getting back into brewing after a 10 year hiatus. Things have changed a little bit, mostly terms and technology, and I am a little confused in the area of gravity readings.

Please review the below list and kindly comment/correct on anything I have wrong

Original gravity is the gravity of the wort after mashing. Hitting this number tells the brewer when mashing is complete, usually 30 minutes to an hour. The reading is taken from the first debris-clear runnings from the mash vessel using 60F wort.
No, OG is after everything is done and the beer is going into the fermenter. It represents total brewhouse efficiency

Final gravity is the gravity of the beer after fermenting. The reading is taken from debris-clear beer from the fermentation vessel at 60F. Hitting the target number means you are done fermenting.
Final gravity has no set number. The "final" gravity is when the reading doesn't change after taking it over several days, thus it's "stable" and "finished". Debris doesn't matter, temperature does, though. 60 is what hydrometers are calibrated for.

Here is where I get really confused:

The gravity on the final runnings of complete sparging is called ??? Hitting 1.008 gravity at 60F means sparging is complete. Or, some brewers merely sparge until the wort runs clear, right?
Most of us sparge until we hit the predetermined preboil volume, but some take gravity readings into account as well, usually checking the gravity of the total collected wort in the kettle and comparing it to the preboil gravity planned.

The gravity of the blended wort (all sparge runnings mixed together) before boiling is called ??? Where should this number be in relation to the original gravity? This is also measured at 60F.
This is just preboil gravity, a specific gravity that's neither "original" or "final".

The gravity of the blended wort (all sparge runnings mixed together) after boiling is called ??? Where should this number be in relation to the original gravity? This is also measured at 60F
THIS is called OG.
Thanks!

Tom B.
See responses in bold above
__________________

_________________________________
Skal!
Den Faaborg Bryggeri

Quote:
Originally Posted by davekippen View Post
Open log Fermenting and gas-can secondary?? I am planning my next brew right now!!
tre9er is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2012, 10:03 PM   #4
m_stodd
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2012
Location: milwaukee, WI
Posts: 331
Liked 56 Times on 38 Posts

Default

OG is pre-fermentation, and FG is post-fermentation, temperature isn't super critical, +-10 won't make a difference. Other readings are just random readings such as pre-boil, post-boil...

These all have to do with the style of beer you're making, you can't just say "1.008 means sparge complete" You do your mash with a calculated amount of water for an hour (or some other time based on your grain bill), then sparge with a calculated amount of sparge water. When all the water is in, you're done adding it.

Are you using a recipe?

http://www.homebrewtalk.com/wiki/index.php/Specific_gravity

__________________
m_stodd is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2012, 10:39 PM   #5
Frenchtom
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 9
Default

Hello everyone and thanks for your prompt responses. I am embarrassed by how inaccurate I was in my thinking but I am glad I asked because your answers helped clarify some problems I was having, namely weak beer. Some follow up questions and answers:

Are you using a recipe? - yes, I buy recipe ingredients from a local retail supplier in order to make things easy on myself. Turns out I was my own biggest problem.

Original gravity is the gravity of the wort after mashing. Hitting this number tells the brewer when mashing is complete, usually 30 minutes to an hour. The reading is taken from the first debris-clear runnings from the mash vessel using 60F wort.
No, OG is after everything is done and the beer is going into the fermenter. It represents total brewhouse efficiency
- so does a gravity reading after mashing essentially mean nothing? Mashing is more about time, temperature and pH than gravity reading?

Pre boil gravity should be lower than the post boil gravity (OG)?

__________________
Frenchtom is offline
 
Reply With Quote Quick reply to this message
Old 11-08-2012, 10:46 PM   #6
menerdari
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2012
Location: Poland, Ohio
Posts: 520
Liked 42 Times on 39 Posts
Likes Given: 16

Default

The gravity reading after mashing is for your reference, you can use it to determine how efficient that particular step was so you can improve on it in the future.
Pre-boil gravity will be lower than post boil because you will have less water after boiling and essentially the same amount of sugar.

__________________
menerdari 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
Gravity questions selbyaaron General Beer Discussion 0 02-24-2012 09:43 PM
Pitching into a higher gravity Stout - Need clarification on starter requirements vast_reaction Fermentation & Yeast 2 10-10-2010 04:46 PM
Clarification on Specific Gravity/Pale Ale Jamie8747 Beginners Beer Brewing Forum 4 06-28-2010 10:24 AM
Gravity questions hinke Beginners Beer Brewing Forum 6 04-12-2010 09:59 PM
Gravity questions cyfan964 Beginners Beer Brewing Forum 2 03-31-2007 07:10 AM