.47 Gal per inch - calculation on 30 qt kettle

[slouch]

I don't have an external site glass on my kettle, and just figured out the volume of the thing is .47 gal per inch. This is on a kettle that is 11.75 inches in diameter.

10 inches of water gives 4.7 gal.

Thought I would pass it on incase anyone is using this size kettle and needs a quick reference.

 

[cladinshadows]

I tried this as well, but in my experience these large pots have a taper to them (presumably due to the manufacturing process). Just saying you should test this out by adding what you know to be 1 through 7 gallons of water to the pot to see if it matches up with the value predicted by geometry... Mine was off by enough to upset mash temperatures based on my strike water volume.

 

[smizak]

I tried this as well, but in my experience these large pots have a taper to them (presumably due to the manufacturing process). Just saying you should test this out by adding what you know to be 1 through 7 gallons of water to the pot to see if it matches up with the value predicted by geometry... Mine was off by enough to upset mash temperatures based on my strike water volume.

Mine has a little taper too. I just did it by brute force, took an accurate gallon container and marked off the inside with little dremel etch lines. In the process I found my 40 qt. pot is more like 37 qts.

 

[slouch]

I tried this as well, but in my experience these large pots have a taper to them (presumably due to the manufacturing process). Just saying you should test this out by adding what you know to be 1 through 7 gallons of water to the pot to see if it matches up with the value predicted by geometry... Mine was off by enough to upset mash temperatures based on my strike water volume.

You are right, if it has a taper, this method wont be entirely accurate. Mine does not have a taper that I can measure, so it works for me.

There are formula for calculating the volume of a section of a cone, which is what a tapering cylinder is, but I don't have those handy.

 

[cladinshadows]

The taper of any of these pots is unlikely to be something that we could measure with a tape measure anyway... I'm just saying it may be easier and more accurate to just fill it up gallon by gallon and use each level as your measurement, like smizak said.

 

[GilaMinumBeer]

Make a stick.

Reading etch marks on the side of a boiling pot can be tricky.