Starting gravity calculation? - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > General Techniques > Starting gravity calculation?

Thread Tools
Old 04-30-2008, 05:59 PM   #1
Mar 2008
Posts: 38

just out of curiosity how do u calculate starting gravity with out taking a hydrometer reading?

Reply With Quote
Old 04-30-2008, 06:01 PM   #2
homebrewer_99's Avatar
Feb 2005
Atkinson (near the Quad Cities), IL
Posts: 17,796
Liked 136 Times on 102 Posts

I think DME is rated like .8% per pound, but you really have to know the volume of water also.
HB Bill

Reply With Quote
Old 04-30-2008, 06:21 PM   #3
Here's Lookin' Atcha!
TexLaw's Avatar
Sep 2007
Houston, Texas
Posts: 3,670
Liked 28 Times on 26 Posts

Grains and extracts have an "extract potential," which is the resulting gravity if you added one pound of the extract (or specialty grain) in question to a gallon of water or mashed one pound of the base grain into a gallon of water at 100% efficiency. You take that extract potential number and do a little algebra.

Beer is good for anything from hot dogs to heartache.

Drinking Frog Brewery, est. 1993

Reply With Quote
Old 05-01-2008, 04:00 AM   #4
Got Trub?
Apr 2007
Washington State
Posts: 1,538
Liked 10 Times on 8 Posts

You could also use brewing software.

For free:


Reply With Quote
Old 05-01-2008, 04:28 AM   #5
Jan 2008
dallas, tx
Posts: 265
Liked 1 Times on 1 Posts

Extract or grains?
Multiply the number of gravity points per pound per gallon by how many pounds you are using and divide by them number of gallons you are making.

6 pounds LME (at 34 gravity points per pound per gallon)x6lbs=204 gravity points.
204/5 gallons=40.8
So with 6 pounds of LME you will have about a 1.041 beer.

If using grains you need to know your efficiency. Say the grains have a potential of 37 gravity points per pound per gallon and your efficiency is 70%.
6 pounds grainx37(gravity points per pound per gallon)x0.7(efficiency)=155.4
155.4/5 gallons=31.08 or a SG of about 1.031.

Reply With Quote
Old 05-01-2008, 11:15 AM   #6
carl spakler
Registered User
Apr 2008
Posts: 294
Liked 2 Times on 2 Posts

Free and easy.

Reply With Quote
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Starting gravity vs. finished gravity? Q2XL All Grain & Partial Mash Brewing 9 06-04-2009 06:47 PM
Can beersmith calculation final gravity based on your mash profile? humann_brewing Brewing Software 1 04-06-2009 04:12 PM
Gravity Calculation for Raspberry Addition explosivebeer Recipes/Ingredients 3 12-17-2008 03:57 PM
Starting Gravity weirrp General Techniques 6 01-15-2008 01:32 AM
Low Starting Gravity pnutbutrsangwich Extract Brewing 6 12-05-2006 07:22 PM

Forum Jump