How to figure out... - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > General Beer Discussion > How to figure out...

Thread Tools
Old 10-21-2009, 08:44 PM   #1
Jun 2007
Mishawaka, Indiana
Posts: 115
Liked 1 Times on 1 Posts

I was listening to a podcast, where someone was able to use a yardstick and multiply the result by some number to get the gallons of wort in his kettle. Since the kettle dimension are different for everyones kettle, does anyone know how to figure this out?
Thanks in advance.
Fairy tales do not tell children that dragons exist.
Children already know that dragons exist.
Fairy tales tell children that dragons can be killed.

Reply With Quote
Old 10-21-2009, 08:52 PM   #2
jcarson83's Avatar
Jun 2006
Springfield, MO
Posts: 928
Liked 16 Times on 11 Posts

1 gal = .13 cubic feet. So pie r square times decimal feet for the depth. Or you could just pour in a gallon and mark it and repeat.

Reply With Quote
Old 10-21-2009, 08:53 PM   #3
May 2009
Los Angeles
Posts: 8,222
Liked 493 Times on 398 Posts

What I do is mark my yardstick with gallon and half-gallon lines on the back.

I used math to figure out how many inches per gallon, and worked from there.

The volume of a cynlinder is the height times Pi * R^2, where R is the radius.
The only thing I had to look up was the conversion from cubic inches to gallons.

Reply With Quote
Old 10-21-2009, 08:53 PM   #4
DRoyLenz's Avatar
Jun 2009
Posts: 702
Liked 4 Times on 3 Posts

This is kind of a cool idea, I think I might run these calculations and try this.

Reply With Quote
Old 10-21-2009, 08:55 PM   #5
I use secondaries. :p
Walker's Avatar
Sep 2005
Cary, NC
Posts: 10,987
Liked 102 Times on 90 Posts

If you consider your kettle to be a simple cylinder, the volume of the liquid in the kettle would be:

</b>where "r" is the inside radius of the kettle and h is the height of the liquid in it.

If you use a yardstick, this will give you a volume in cubic inches, which you can convert to gallons with the rule:

1 gallon = 231 cubic inches

I took the cheater method and filled my kettle with a 4 gallons of water, stuck my Big Spoon in it, and marked the waver level on the spoon.

Added another 1 gallon of water and made another mark.

Repeat until you have a spoon that can serve as a dip-stick and tell you how much is in the kettle.
Ground Fault Brewing Co.

Reply With Quote
Old 10-21-2009, 08:57 PM   #6
uwjester's Avatar
Sep 2007
Fort Collins, CO
Posts: 688
Liked 6 Times on 6 Posts

If you know you have a 10 gallon kettle, divide the height by 10 to find how many gallons per inch/centimeter. That way, you can measure from the top and still know. I'm all for the calculations, but this may be an easier way. My 15 gallon kettle is 15" tall, so I just know that each inch is 1 gallon.

Edit: I had the numbers backwards. They should be right now.
This space intentionally left blank.

Reply With Quote
Old 10-22-2009, 01:18 AM   #7
Aug 2009
Twin Cities, MN
Posts: 2,509
Liked 36 Times on 35 Posts

My keggle has a curved bottom. I poured in gallons of water to find out how many inches per gallon. It came out to:

2.25 inches for the first gallon
1.38 inches for every gallon thereafter....

Therefore, 6 gallons would be 2.25+1.38*5 inches.

Reply With Quote
Old 10-22-2009, 03:38 AM   #8
Scut_Monkey's Avatar
Jan 2009
Pittsburgh, Pennsylvania
Posts: 2,656
Liked 14 Times on 14 Posts

Yeah I do the old marked stick for my measurements. I try to limit as much math as possible during my brewday to allow for more fun (ie beer).

Reply With Quote
Old 10-22-2009, 12:31 PM   #9
Licensed Sensual Massage Therapist.
Homercidal's Avatar
Feb 2008
Reed City, MI
Posts: 31,931
Liked 5173 Times on 3506 Posts

I've been meaning to do this for a while now. Somehow it never seems to get done.
Day after day, it reappears. Night after night my heartbeat shows the fear. Ghosts appear and fade away. Come back another day.

Reply With Quote
Old 10-22-2009, 01:40 PM   #10
springer's Avatar
Feb 2008
Wappingers falls NY
Posts: 4,743
Liked 26 Times on 24 Posts

can't do this with a Coors keg its not a straight cylinder I had to use the old add a gallon to the HLT and mark the site glass . The keggle was easy its pretty much linear .
'The taxpayer: That's someone who works for the federal government but doesn't have to take the civil service examination.'- Ronald Reagan

Reply With Quote
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Can't figure it out?? DemonCleaner All Grain & Partial Mash Brewing 7 06-10-2009 10:53 PM
Can't figure this out. burnninator Beginners Beer Brewing Forum 16 12-03-2008 05:43 AM
Can't figure it out Bad Shark Brew General Beer Discussion 3 04-09-2008 09:16 PM
Can you figure this out? JeepGuy General Chit Chat 12 12-12-2007 05:52 PM
Can you figure ABV by OG? mayday1019 Beginners Beer Brewing Forum 2 10-16-2007 01:09 AM

Forum Jump