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alee

Well-Known Member
I used my 9 gal stainless brew pot for my first all grain this afternoon. Because I wanted to know when I was at my target 6.5 gal wort level and then my 5 gal target level, I did a little search and found this website for calculating the depth of liquid for a particular volume and radius pot.
Cylinder Calculator
You will have to convert gallons required to cubic inches (multiply by 231) to get the required depth in inches.
I then took a blunt screwdriver and hammered a very slight indentation on the outside of the pot at both the 6.5 and 5 gallon marks so that is showed though on the inside of the pot. It saves measuing with liquid and wasting water!
Hopefully someone will find this useful.

newbeerpig

Well-Known Member
Very useful, dang math though... will be very useful for my new kettle because it doesn't have any marks inside.

GunnerMan

Well-Known Member
I just measured my pot like you did and found a gallon = 2.1 inches or so in my pot, so I took a yard stick and put marks every 2.1 inches. I did this on each of my pots on each end of the stick.

McKBrew

Well-Known Member
You guys are too smart.

I just poured in a gallon at a time and marked the stick after each one.

beesy

Well-Known Member
very nice......however I just want to throw another comment in.

I it would be interesting to see how well you math measures up to the fill and mark method due to differences in abilities to accurately measure the radius of your pot. I would think unless you had a very large set of calipers or other fine measuring device, you could be off a little. Also, ever notice most pots are not perfectly vertical? This will also throw your measure off because the distance between marks becomes less as you read the caudal side of the pot (smaller diameter at bottom than top) as most are tapered slightly out as they are pressed into shape and this allowed the die to come out of the pressed pot easier. Just something to think about....

OP

alee

Well-Known Member
My five gallon mark was pretty darned accurate. I measured 5 gallons of water into my 6 gallon carboy and marked the outside with permanent ink. My 5 gal of wort filled the carboy really close to the mark.
I was really just shooting for an estimate. My pot looks pretty straight to me. Also, I just measured the diameter and divided by 2!

GunnerMan

Well-Known Member
Yeah you will be off a bit but the day I cause my self to go through enough stress to make sure my volumes are accurate to the 1/20th of a gallon is the day I quit brewing. I measured my marks to at the 1 and 2 gallon for accuracy and they were fine. My ag batch last night yeilded the perfect amount so I think I am ok.

Matt Up North

Well-Known Member
Home depot, get a dowel for a buck, measure 5 gallons into the pot, stick the dowel in and mark it. Then add a gallon and mark that, and so on and so on. Best buck you have spent

ryan0914

Well-Known Member
Another formula to figure this out so you will know the exact measurement

"Volume"- 1 gal,2 gal 3 gal... the volume you want to know the height of..(usually use 1 for the height of 1 gal)

"231"- the formula is for cubic inches and there are 231 cu/in in 1 gal so that converts to gal

"h"- height in inches your looking for. (usually use 1)
this is to find how many inches

bruin_ale

Well-Known Member
Yeah, dip stick is great and basically free (did that for years) - but a sightglass is so much nicer. If you're doing all grain, it should be required. Much easier to just watch the liquid level drop on a sightglass to tell how much water you moved from HLT to mash.

BWN

Well-Known Member
I bought a metal yard stick at home depot and measured a gallon to be 1.5 inches(Well actually the first gallon is 1 5/8 inches) It involves some math but it works for me.

bovineblitz

Well-Known Member
Yeah, dip stick is great and basically free (did that for years) - but a sightglass is so much nicer. If you're doing all grain, it should be required. Much easier to just watch the liquid level drop on a sightglass to tell how much water you moved from HLT to mash.
That'd be great if I had a permanent spot for my pot but I have to put it away and hang it from the ceiling after each use... wouldn't dare use a sightglass in my case.

emjay

Well-Known Member
bovineblitz said:
That'd be great if I had a permanent spot for my pot but I have to put it away and hang it from the ceiling after each use... wouldn't dare use a sightglass in my case.
Why? Most of the aftermarket ones are made using a polycarbonate tube, the material used as "bulletproof glass", and is also used to make shatter-proof lenses for eyeglasses and even safety goggles. Just make sure it is polycarbonate and you should be fine.

I have an actual glass sight gauge (borosilicate, same type of glass as Pyrex labware) on my kettle even though I also have to put it away after each use - in my case, crammed underneath the stairs. I can only really get away with it because my kettle is a Blichmann Boilermaker, which has the best-designed and most well-protected sight glass on the market.

The disadvantages to polycarbonate are that, while it won't shatter like glass will due to impacts, it scratches more easily. And while borosilicate remains clear over extended periods of time, the heat from boiling causes polycarbonate to gradually get cloudy over time. But on the bright side, and nearly negating these disadvantages, is that polycarbonate tubing is dirt cheap. Once you have the fittings, you should be able to buy any realistic diameter for less than \$10 for an 8-foot length (which is how it's often sold outside of homebrew shops), which, depending on the height of your kettle, is adequate for many years' worth of replacements.

HHP

Well-Known Member
I think I am going to go with the tubing sight glass, I cant really see any downsides to it: it doesn't break, easy to replace, and it cheap. It just seems like a win win.

rcrabb22

Well-Known Member
Are you all taking measurements with the liquid at mash temps or whatever temp you will measuring volumes? Liquids expand and contract like anything else when heated and cooled. Boiling wort will loose approx 4% volume when cooled to pitching temps due to contraction.

nostalgia

Well-Known Member
I use a metal yardstick and the calculator I wrote here. It takes heating and cooling expansion (4%) into account too if you need that.

-Joe

Seven

Well-Known Member
Are you all taking measurements with the liquid at mash temps or whatever temp you will measuring volumes? Liquids expand and contract like anything else when heated and cooled. Boiling wort will loose approx 4% volume when cooled to pitching temps due to contraction.
Agreed. Measuring the water level when cold vs. boiling will give quite different results.

bruin_ale

Well-Known Member
Are you all taking measurements with the liquid at mash temps or whatever temp you will measuring volumes? Liquids expand and contract like anything else when heated and cooled. Boiling wort will loose approx 4% volume when cooled to pitching temps due to contraction.
I took my measurement at room temp.. accurate enough for me. I think I lose more to hop absorption than I do from the inaccuracy. It's easy to account for though, once you're run a boil it's pretty easy to dial in how much you need to start with to get what you want into the fermentor. The sight-glass is so nice in that regard - once I hit 7.25G in my boil kettle I'm confident I'll get 5.5G in my carboy. Again, a diptube works fine - just nice to have a sightglass to look at instead of continually dropping a dipstick in. It allows me to do other things while keeping an eye on volume. Only downside is having to drill a hole in your kettle.

AnthonyC

Well-Known Member
Another formula to figure this out so you will know the exact measurement

"Volume"- 1 gal,2 gal 3 gal... the volume you want to know the height of..(usually use 1 for the height of 1 gal)

"231"- the formula is for cubic inches and there are 231 cu/in in 1 gal so that converts to gal

"h"- height in inches your looking for. (usually use 1)
this is to find how many inches
I think the calculation should be:
Height = (volume * 231) / pi * R^2

Volume = Area * Height

so

Height = Volume / Area

Malticulous

Well-Known Member

I use the ugly spoon.

emjay

Well-Known Member
Malticulous said:
I use the ugly spoon.
I have that exact same spoon, but I use it only in my fermenter. I have a big-ass stainless steel spoon for my kettle, though I use a sight glass for measuring volume anyways.

Malticulous

Well-Known Member
I have a spoon for the mash, a spoon for the boil and a spoon for the fermenter.

emjay

Well-Known Member
Malticulous said:
I have a spoon for the mash, a spoon for the boil and a spoon for the fermenter.
Me too, sorta. Except I have two spoons for the fermenter (one with my "sours" equipment), and I have both a wooden and stainless steel mash paddle.