New Giveaway - Wort Monster Conical Fermenter!

Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > Gravity question




Reply
 
LinkBack Thread Tools Display Modes
Old 01-10-2013, 11:57 PM   #1
NumeroUno
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 5
Default Gravity question

I am new to all grain. Here is my question. I brewed a porter. Mashed and sparked. Before the boil took a hydrometer reading and temperature reading. Using the gravity correction chart on page 35 of Designing Great Beers by Ray Daniels I added the correction and missed my OG by .01. I added a pound of DME and boiled. I took another reading after the boil and was over my gravity by .01. My question is if I take a reading after mash and sparge, how do I know if I am going to get close to the OG? Appreciate any help!



__________________
NumeroUno is offline
 
Reply With Quote Quick reply to this message
Old 01-11-2013, 12:00 AM   #2
jeepinjeepin
Feedback Score: 1 reviews
Recipes 
 
Join Date: Apr 2011
Location: Winston-Salem, NC
Posts: 6,391
Liked 1043 Times on 1022 Posts
Likes Given: 35

Default

If I understand what you are asking it has to do with boil off. You are going to lose a volume of water during the boil which will raise your OG. How much depends on your pot, how vigorous you boil, etc. There are calculators to figure it.



__________________

Walmart is about the only reason for open or concealed carry that I can get behind. -Randar

jeepinjeepin is offline
 
Reply With Quote Quick reply to this message
Old 01-11-2013, 12:34 AM   #3
NumeroUno
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2012
Posts: 5
Default

Can you recommend a source for researching the boil off effect on OG?

__________________
NumeroUno is offline
 
Reply With Quote Quick reply to this message
Old 01-11-2013, 02:07 AM   #4
jeepinjeepin
Feedback Score: 1 reviews
Recipes 
 
Join Date: Apr 2011
Location: Winston-Salem, NC
Posts: 6,391
Liked 1043 Times on 1022 Posts
Likes Given: 35

Default

Quote:
Originally Posted by NumeroUno
Can you recommend a source for researching the boil off effect on OG?
I feel like it should be in "How To Brew" but a quick scan didn't turn it up. There are several apps that will calculate it for you. You have to be able to accurately measure volume.
__________________

Walmart is about the only reason for open or concealed carry that I can get behind. -Randar

jeepinjeepin is offline
 
Reply With Quote Quick reply to this message
Old 01-11-2013, 02:19 AM   #5
duboman
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jul 2011
Location: Glenview, IL
Posts: 5,809
Liked 429 Times on 402 Posts
Likes Given: 199

Default

First of all, at what temp did you correct. While there are estimators for this correction, anything over 100 degrees is really less than optimal and the readings can be quite off.

That said, most pre-boil OG readings IME are about 8-10 points from the post boil so you can assume with a normal boil over 60 minutes your OG will increase by that amount.

So if you miss your pre-boil you can opt to add DME, boil harder or longer or dilute depending upon which way you miss.

You added DME to raise your gravity but then boiled too hard and experienced more boil off, hence the higher OG.

Boil off can vary depending on how hard you boil or ambient emperor ire and humidity. Cold dry air=more, hot humid =less



__________________
Nothing Left to do but smile and drink beer.....

The Commune Brewing Company-Perfecting the "art" of beer since 2010
duboman 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
Gravity Question drlars Beginners Beer Brewing Forum 16 07-25-2012 09:37 PM
Gravity question DeanMachine Beginners Beer Brewing Forum 4 12-31-2010 06:41 AM
Gravity Question Fritobandito Mead Forum 2 10-14-2010 01:46 PM
Gravity question. eppo Beginners Beer Brewing Forum 1 12-15-2009 12:07 PM
Gravity Question Kriznac Beginners Beer Brewing Forum 9 01-09-2009 02:26 AM