How do you calibrate your water volumes?

[h22lude]

I'm trying to make sure my bucket, carboy and kettle volume markings are correct. I just checked one of my buckets using a measuring cup (2 cup pyrex). After 32 cups, the 2 gallons of water was well under the 2 gallon mark on my bucket. Not sure if the measuring cup is off or the bucket is.

So that leaves me with is my measuring cup off, my bucket or both. I used another bucket (not fermentor) to mark my sight gauge. Now i'm thinking that may not be accurate.

What is the best way to measure volume? I know weighing is a really accurate measurement but I don't feel like buying a good scale just for this. I have a hop scale but I don't think it would do the 8.33lbs for a gallon.

 

[ArkotRamathorn]

You could take a 1 gallon milk jug and measure water that way. I don't know how measuring 32 cups of water wouldn't get you pretty close.

I use a 1 gallon jug from a bottle of cider. I would hope that any vessel marked as "1 gallon" would measure pretty close to a gallon each time I fill it nearly to brim.

 

[botigol]

Could you check the weight of the 2 cup measurement on your hop scale?

 

[Jimbodaman]

If you have a normal cylindrical kettle like most measure as accurately as possible the inside diameter of the pot. ((pi) * radius^(2))*(height) will give you the amount of of water in cubic inches at that height. There is, according to google, 231 cubic inches per gallon. 231/(pi* r^(2)) will give you the amount of inches per gallon.
r= diameter/2.
Sorry if that's a bit confusing. Cheers

 

[Jimbodaman]

Then I would take a wooden dowel rod and notch the gallons.

 

[pricelessbrewing]

If you have a normal cylindrical kettle like most measure as accurately as possible the inside diameter of the pot. ((pi) * radius^(2))*(height) will give you the amount of of water in cubic inches at that height. There is, according to google, 231 cubic inches per gallon. 231/(pi* r^(2)) will give you the amount of inches per gallon.
r= diameter/2.
Sorry if that's a bit confusing. Cheers

I use a stainless ruler, as they're premarked, more accurate, and more precise than a manually marked dip stick.

 

[h22lude]

You could take a 1 gallon milk jug and measure water that way. I don't know how measuring 32 cups of water wouldn't get you pretty close.

I use a 1 gallon jug from a bottle of cider. I would hope that any vessel marked as "1 gallon" would measure pretty close to a gallon each time I fill it nearly to brim.

Using a store bought gallon of water might be a good idea. I would think a gallon of water would come with exactly a gallon of water.

In theory 32 cups should be exactly 2 gallons. Since it wasn't, that means either the measuring cup is wrong or my bucket is wrong.

Could you check the weight of the 2 cup measurement on your hop scale?

Yeah I may be able to do that. Might try that after putting my son to bed.

 

[h22lude]

If you have a normal cylindrical kettle like most measure as accurately as possible the inside diameter of the pot. ((pi) * radius^(2))*(height) will give you the amount of of water in cubic inches at that height. There is, according to google, 231 cubic inches per gallon. 231/(pi* r^(2)) will give you the amount of inches per gallon.
r= diameter/2.
Sorry if that's a bit confusing. Cheers

Hmmm never thought about doing it that way. Just not sure how accurate my measuring would be.

 

[TallDan]

Every time you filled your 2 cup measuring cup, you had a certain margin of error. Multiply that sixteen times and I'm not surprised that the measurements didn't agree. I'd say that it's quite possible that they are both very accurate.

 

[h22lude]

Every time you filled your 2 cup measuring cup, you had a certain margin of error. Multiply that sixteen times and I'm not surprised that the measurements didn't agree. I'd say that it's quite possible that they are both very accurate.

When I say it was off, I don't mean by 1/2 cup of less. This was 2 to 3 cups off at least.

 

[Amadeo38]

Take a gallon jug of water and a gallon jug empty to your LHBS and use their (hopefully calibrated) grain scale to check that the full jug weighs 8.33lbs when you tare it with the empty jug first. Then you'll know if the gallon jug is accurate to use for your purposes. Oh, and this goes without saying, but bring your LHBS guys a home brew or two for the use of their scale!

 

[h22lude]

Take a gallon jug of water and a gallon jug empty to your LHBS and use their (hopefully calibrated) grain scale to check that the full jug weighs 8.33lbs when you tare it with the empty jug first. Then you'll know if the gallon jug is accurate to use for your purposes. Oh, and this goes without saying, but bring your LHBS guys a home brew or two for the use of their scale!

I was just thinking about that. I was thinking of bringing a bucket and weigh out a gallon at a time and mark the bucket. Marking a jug using your method would probably be easier.

Oh definitely. I usually bring some kind of 6 pack every time I go. Sometimes I go just to have and share beer lol

 

[murphyslaw]

I used an ice tea pitcher. That indicated that my bucket markers were way off. Then i remeasured using milk jugs and that gave me very different results. Like .75g off over 8g.

Milk jugs should be right. Weights and measures laws probably require it.

 

[Scuba_Steve81]

If you have a normal cylindrical kettle like most measure as accurately as possible the inside diameter of the pot. ((pi) * radius^(2))*(height) will give you the amount of of water in cubic inches at that height. There is, according to google, 231 cubic inches per gallon. 231/(pi* r^(2)) will give you the amount of inches per gallon.
r= diameter/2.
Sorry if that's a bit confusing. Cheers

You have that backwards.

(πR^2)*height/231=gallons

All measurements in inches.

 

[h22lude]

I used an ice tea pitcher. That indicated that my bucket markers were way off. Then i remeasured using milk jugs and that gave me very different results. Like .75g off over 8g.

Milk jugs should be right. Weights and measures laws probably require it.

I think milk jugs are the easiest way to go. I may get 2 or 3 and make sure they all measure out to the same (or weigh them). I know this may be a little overboard but I want to make sure my sight gauge is accurate as I don't think my last batch was correct because my measurements were off.

 

[h22lude]

Just measured out 2 cups using 8.3oz per cup. My Pyrex measuring cup was almost spot on. So that means my fermenting bucket is off which makes sense. My last batch I had more wort left over than I should have. If each gallon mark was off on my bucket, that would give me more than I should end up with.

Time to go buy some gallon jugs and measure each bucket and carboy.

 

[Anyhowe]

I just weigh my water. 60 lbs per 5 gal batch and adjust the grains accordingly. I'm making beer not landing a shuttle and what really matters is consistency.

 

[Jaybird]

Go by weight in your jug or even in your 5000 ml Flask. I believe water is 8.3 # per gallon (google it to be sure) then mark your flask. I just had to do this as ALL my Erlenmeyer flasks were WAY OFF...

Cheers
Jay

 

[TallDan]

When I say it was off, I don't mean by 1/2 cup of less. This was 2 to 3 cups off at least.

Yeah, but you measured sixteen times! If you were an ounce short on each measurement, that would put you two cups off.

 

[h22lude]

I just weigh my water. 60 lbs per 5 gal batch and adjust the grains accordingly. I'm making beer not landing a shuttle and what really matters is consistency.

No, making beer isn't like landing a shuttle but to get consistent beer measurements need to be consistent. A cup here or there won't make a difference but to be .75 gallons off will make a difference.

Go by weight in your jug or even in your 5000 ml Flask. I believe water is 8.3 # per gallon (google it to be sure) then mark your flask. I just had to do this as ALL my Erlenmeyer flasks were WAY OFF...

Cheers
Jay

I'm starting to think everything that has volume markings is off. My bucket wasn't correct. I need to check my flask now. My sight gauge isn't correct because I used my bucket. I don't feel like buying a scale so I'll most likely bring a jug to my lhbs to use his scale.

Yeah, but you measured sixteen times! If you were an ounce short on each measurement, that would put you two cups off.

I understand what you are saying but I can tell you I wasn't short. If anything I measure to just above the line so I would have been over. I'll do it again and then get an exact amount that I am short the 2 gallons.

 

[pricelessbrewing]

Yeah, but you measured sixteen times! If you were an ounce short on each measurement, that would put you two cups off.

Instrumental uncertainty can be a B#$#$.

Here's another way to think of it, and is almost always the first lab a physics student does...

Measure the time it takes to for something to swing/rotate 10x, measuring each rotation seperately. This has 10x the uncertainty (in this case it's due to reaction time)

Now measure 10 rotations all at once. This has 1x the uncertainty, and so each individual measurement is more accurate than the previous method.

Measure all at once, don't use a measuring cup or jug or whatever. Get a ruler, or weight it out...

 

[laredo7mm]

You have that backwards.

(πR^2)*height/231=gallons

All measurements in inches.

He was giving the formula for how many inches of water in a pot of a specific radius for one gallon. The formula you gave is the same as what he said if you use one gallon and then solve for height:

(πR^2)*height/231=gallons

(πR^2)*height/231=1

(πR^2)*height=231

height=231/(πR^2)

 

[h22lude]

This time I poured water into my 2 cup measuring cup then weighed it out in oz to make sure. I didn't measure the amount I was short last time but it looked very close to what I was short this time.

I think my best bet is weigh a gallon jug and mark the water line. That should be pretty accurate to calibrate my sight gauge. I know the best way is to weight each gallon but like I said, I don't have a scale or really want to buy one.

 

[Anyhowe]

No, making beer isn't like landing a shuttle but to get consistent beer measurements need to be consistent. A cup here or there won't make a difference but to be .75 gallons off will make a difference.




.

Well i cant disagree with your thoughts and you should be more accurate. That is why I suggest weight. But remember that regardless of how far out your measurements, if you are out with consistency then it doesn't matter after the first beer.

 

[h22lude]

Well i cant disagree with your thoughts and you should be more accurate. That is why I suggest weight. But remember that regardless of how far out your measurements, if you are out with consistency then it doesn't matter after the first beer.

I'm not quite sure what you mean by this. To me, it sounds like you are saying if you are not consistent then accurate measuring is moot. Accurate measuring is a part of consistency. Accurate measuring, good brewing procedure and fermentation temp control will make consistent beer. If any one of those are off, it is unlikely you will make consistent beer. That is why I'm a little confused as to why you say if you aren't consistent then accurate measuring doesn't matter after the first beer. You need accurate measuring to be consistent. If you are spot on with brewing and temp control but you measure 15lbs of grain instead of 12lbs then you measure 10lbs the next batch, you will not be consistent.

Instrumental uncertainty can be a B#$#$.

Here's another way to think of it, and is almost always the first lab a physics student does...

Measure the time it takes to for something to swing/rotate 10x, measuring each rotation seperately. This has 10x the uncertainty (in this case it's due to reaction time)

Now measure 10 rotations all at once. This has 1x the uncertainty, and so each individual measurement is more accurate than the previous method.

Measure all at once, don't use a measuring cup or jug or whatever. Get a ruler, or weight it out...

This makes perfect sense. You would think if you measured the 10 rotations individually you could get a more accurate measurement but there is 9 times more changes of being off then if you measured all 10 rotations together.

My issue right now is trying to calibrate my sight gauge. To do that I need to measure the 10 times (using your rotation example) so I need to make sure each gallon is measured correctly. It seems at this point the only real way to do that is weighing gallon jugs.

 

[Twotaureanbrewing]

Read through this thread for the most part and all I can think is, really, really how much does even a 1/4 or half gallon matter either way? Is it going to ruin the beer, ruin the recipe? No, most likely not.

Make note of your measurement at end of boil (I use a stainless ruler) in the kettle. If your short in your fermentor, next time around just sparge a little more if your short(before boil).

For my strike and sparge water volumes I use a premarked 6 gallon pail from my LHBS. I get it close to the mark, usually a little over. Never steered me wrong.

 

[TallDan]

Accuracy and consistency are two different things. If your recipe calls for 12lb of base malt, your scale is off, and you actually put in 12.5lb, that's inaccurate. But, if every time you brew that recipe you use the same scale and weigh out 12.5lb of base malt (thinking that it's 12lb) you can still be consistent.

Consistent process makes for consistent results. You do not need to be accurate to be consistent.

Now let's say that you're inconsistent, and sometimes you put 12lb of base malt in, sometimes 13. You may even accurately weigh out your inconsistent amounts, but you will not get consistent results.

So, your sight gauge is likely to be consistent even if it's not accurate. If you use that sight gauge to measure out your strike and sparge water every time, you can expect consistent results.

As mentioned previously, we're brewing beer here, not landing a person on Mars. If your numbers don't match up with anything outside of your brewery, it doesn't matter as long as your process in consistent and you're getting the results you want.

All of that said, I would like all of my equipment to be accurately calibrated, but I realize that I'm not working with calibrated lab grade measuring equipment. The sight gauge on my kettle is "good enough" as are my scales.

 

[Anyhowe]

Accuracy and consistency are two different things. If your recipe calls for 12lb of base malt, your scale is off, and you actually put in 12.5lb, that's inaccurate. But, if every time you brew that recipe you use the same scale and weigh out 12.5lb of base malt (thinking that it's 12lb) you can still be consistent.

Consistent process makes for consistent results. You do not need to be accurate to be consistent.

Now let's say that you're inconsistent, and sometimes you put 12lb of base malt in, sometimes 13. You may even accurately weigh out your inconsistent amounts, but you will not get consistent results.

So, your sight gauge is likely to be consistent even if it's not accurate. If you use that sight gauge to measure out your strike and sparge water every time, you can expect consistent results.

As mentioned previously, we're brewing beer here, not landing a person on Mars. If your numbers don't match up with anything outside of your brewery, it doesn't matter as long as your process in consistent and you're getting the results you want.

All of that said, I would like all of my equipment to be accurately calibrated, but I realize that I'm not working with calibrated lab grade measuring equipment. The sight gauge on my kettle is "good enough" as are my scales.

Yea, what he said. 🍻

 

[h22lude]

Accuracy and consistency are two different things. If your recipe calls for 12lb of base malt, your scale is off, and you actually put in 12.5lb, that's inaccurate. But, if every time you brew that recipe you use the same scale and weigh out 12.5lb of base malt (thinking that it's 12lb) you can still be consistent.

Consistent process makes for consistent results. You do not need to be accurate to be consistent.

Now let's say that you're inconsistent, and sometimes you put 12lb of base malt in, sometimes 13. You may even accurately weigh out your inconsistent amounts, but you will not get consistent results.

So, your sight gauge is likely to be consistent even if it's not accurate. If you use that sight gauge to measure out your strike and sparge water every time, you can expect consistent results.

As mentioned previously, we're brewing beer here, not landing a person on Mars. If your numbers don't match up with anything outside of your brewery, it doesn't matter as long as your process in consistent and you're getting the results you want.

All of that said, I would like all of my equipment to be accurately calibrated, but I realize that I'm not working with calibrated lab grade measuring equipment. The sight gauge on my kettle is "good enough" as are my scales.

Yes you are correct. You can be consistent with inaccurate measurements as long as you keep making the same inaccurate measurements. That isn't what I want. To me, that is a negative consistency. Sure you can produce the same beer each time and I guess you can adjust BeerSmith and your recipe to that inaccurate measurement but why when you can change your measurements to be accurate and now have a correct consistency.

A good example of why negative consistency is bad is with a thermometer. If your thermometer is reading 10° cooler than it really is, you may think you are pitching at 70° but you are really pitching at 80° each time. Your are consistent but is it good? You may produce good beer but you can also get off flavors with some yeasts. Obviously this is different than having an extra half gallon but I used it just to show my point.

Just like everything else in brewing, each home brewer does things differently. Some people don't mind if their measurements aren't accurate as long as they can make the same beer again. Personally, I want my measurements to be accurate to make consistent beer.

No one is wrong. Everyone just does things differently.

 

[Derp]

I used a plastic pitcher from a German beer/food festival that has a 1/2 gallon measurement mark on it. I just filled it to the line and marked my keggle sight glass and Speidel fermenters. The keggle shows 15.5 gallons when filled, so I think it's close enough.

I just filled the pitcher and weighed it. After doing the math, it appears that my 15.5-gallon keggle might be short about 16 ounces as marked. I can live with that.