What's the full volume of "3 gallon" carboy?

[whackfol]

Anyone know with some degree of accuracy what the volume of a "3 gallon" carboy is to the bottom of the spout? I'm fine with liters or gallons.

Alternatively, do you know the liter volume printed on the bottom of the "3 gallon" carboy and what height they are measured to on the carboy?

I have most of my different carboys graduated with volume markings but can't seem to find a 3G with markings.

 

[BernardSmith]

I am not sure the answer but what you may want to do is simply fill up three 1 gallon carboys and mark the 3 gallon vessel at the 3 gallon height. My sense is that the measure is at the height of the shoulder. That, by the way, is a good reason to always make far more wine or mead than the nominal amount you intend to make. Those nominal amounts are always smaller than the amount you need to fill a carboy so that there is little or no headroom.

 

[cmason1957]

You are going to have to figure this one out yourself. I am firmly convinced that every carboy I have is slightly to somewhat different in what it holds. My solution is the same always make a bit more than what I think I need.

 

[jburtner]

+1 on making extra for top up. Through various craigslist carboy purchases i’ve ended up with different manufacturers versions of 3g, 5g, and 6g carboys and they’re all slightly different geometry. I also have plenty 1g and 1/2g jugs for storing top-up as well as 750’s and 375’s.

I’m making much better effort now to keep it all topped up with absolute minimal headspace even though I also use headspace eliminators on the carboys.

Cheers!
Johann

 

[whackfol]

Thanks for your effort. I found my reference carboy.

FWIW: Italian carboy, 3 gallon on box, 11.4L in mold, 11L just above shoulder, and 11.75L 2 inches from top. Not sure where they measured the 11.4L

 

[NorCal]

I've racked from one 5 gallon carboy to another and had it overflow by a significant amount. They vary within an few % manufacturer to manufacturer.

 

[whackfol]

Norcal, agreed. It has been a while since I used carboys and I wanted to make an SO2 addition. I could not find the reference one for 3G and could not read the bottom with the carboy full. Just knowing what the manufacturer considered the "3 gallon" to hold from the mold was all I needed. Being off by 5% or so would not have affected this first SO2 addition.

 

[Rocky]

I find that all carboys differ slightly, even ones that appear "identical."

 

[mainshipfred]

I don't think I have a single carboy that holds the same amount of wine. Some vary way more than others.

 

[Scooter68]

I realized the same thing - Different capacities - This past spring. Sadly I haven't marked the carboys to identify the higher vs lower volume ones. So each racking time is an adventure - Befuddling sometimes when you worry about the lost volume and there isn't any, OR You should have no significant volume lost but suddenly it doesn't quite make it up to the narrow part of the neck and yet the amount left behind is only 3-4 oz.

Obviously quality control and 'truth in packaging' is not applied to carboys.

(Using 3 gallon carboys)

 

[cmason1957]

I realized the same thing - Different capacities - This past spring. Sadly I haven't marked the carboys to identify the higher vs lower volume ones. So each racking time is an adventure - Befuddling sometimes when you worry about the lost volume and there isn't any, OR You should have no significant volume lost but suddenly it doesn't quite make it up to the narrow part of the neck and yet the amount left behind is only 3-4 oz.

Obviously quality control and 'truth in packaging' is not applied to carboys.

(Using 3 gallon carboys)

I'm not sure it is a quality control or 'truth in packaging' issue, but more of a blown glass issue. They are probably made on a glass blowing machine and not by hand, but even with a machine, I wonder how much variation there is. Certainly if they were by home, then there would be no consistent sizing.

If you need exact amounts, you probably have to use all plastic, they are made in a mold and are probably all the same.

 

[stickman]

Agree with @cmason1957 the glass blowing machine uses a mold, but that only gauges the outside diameter of the carboy, the glass thickness varies to some extent, so the inside diameter is less reliable. I'm sure there is a host of variables associated with how the machine is operated that determines the repeatability. Who's on shift today.......

 

[Rocky]

Well, mathematically and in the absolute sense, there are no two vessels in the World that have the same volume.

 

[cmason1957]

But, I would imagine that if you take the average of the volumetric deviations for the plastic it will be significantly smaller than the same measurement for the glass. I'm sure they have an allowable tolerance.

 

[Scooter68]

I'm not sure it is a quality control or 'truth in packaging' issue, but more of a blown glass issue. They are probably made on a glass blowing machine and not by hand, but even with a machine, I wonder how much variation there is. Certainly if they were by home, then there would be no consistent sizing.

If you need exact amounts, you probably have to use all plastic, they are made in a mold and are probably all the same.

Guess I wonder about why other glass containers don't vary that much in volume or do they? Do wine bottles vary but we just don't notice because their volume isn't that much anyway? Are they made differently. Really wondering about that - I don't know why the methods of production would be that different. That's why I wonder if it comes down to the fact that nobody is really requiring that those carboys be that accurate in volume. Simply because they aren't sold with anything in them whereas wine bottles are typically going to be sold at some point with customer expecting an exact volume.

 

[cmason1957]

Just guessing, but size issue?? as in a 6 gallon carboy is 23 Liters (more or less), so maybe 24 times as large as a 750 ml bottle. Or maybe it is (as you pointed out) someone cares did I really get 750 Ml of wine, liquor, etc. whereas we as winemakers have little expectation that our 6 gallon carboys are really 23 liters. We need a glass manufacturers rep to weigh in, instead of a silly computer programmer who can only count 0 and 1.

 

[Scooter68]

BOTTOM LINE FIRST - The volume difference between my 3 gallon carboys is as much as 10 ounces.
Let me explain what I did to get to that number.
Today I racked 3 three gallon batches from/to "3 Gallon" carboys and here's what I found. (Batches in order were Elderberry, Mango/Pineapple, and Peach)
Each time I racked into a freshly cleaned carboy.
The first rack was into one of my spare 3 gallon carboys. (Container A for Comparison)
After racking I dumped out the sediment loaded wine that was not racked, Cleaned that carboy, then racked the next batch into the freshly washed and sanitized carboy I had just emptied.\
1) Elderberry batch (Carboy B) racking went fine - The clean spare carboy (Container A) was filled to within 1 1/2 " of the top. Left behind (In Container B)was approximately 6 oz of wine with sediment. I actually took 4 ozs of that as our sample for that batch and then dumped the other 2 oz down the drain. Note No topping off the carboy racked into so it was at least 6oz lower capacity.

2) Mango/Pineapple batch (Container C) rack into newly cleaned carboy ended up with me needing to add 10 oz of extra wine I had for that batch in order to top off container (B). I had less than 5 oz of sediment loaded wine leftover from that carboy so I estimating about a 4-5 oz difference in capacity. ( I only had 3 oz for our sample from that batch and poured out another 2 oz of heavy sediment)

3) Peach batch (Container D) was racked into the new emptied, cleaned, sanitized carboy from batch two(Container C). At the end of that racking I had to add 14 oz of extra wine set aside for that batch. ( I actually left 2 oz in the 16 oz bottle the extra wine was kept in. (Yes, it was under airlock) the leftover amount of wine with heavy sediment was 4 oz, alas there was nothing to keep for a sampling tonight.

You are welcome to check my math and throw questions my way as I did enjoy those sample and my judgement now as I type this may be faulty.

 

[BernardSmith]

But liquid volume is not constant. It will change by temperature. So when you state that something holds 3 gallons at what temperature is that volume accurate? And does all liquid expand and contract at the same rate when heated or cooled?

 

[sour_grapes]

But liquid volume is not constant. It will change by temperature. So when you state that something holds 3 gallons at what temperature is that volume accurate? And does all liquid expand and contract at the same rate when heated or cooled?

A temperature swing of 10 degF will change the volume of 3 gallons of water by about 12 mLiters, or about a tablespoon.

 

[Scooter68]

But liquid volume is not constant. It will change by temperature. So when you state that something holds 3 gallons at what temperature is that volume accurate? And does all liquid expand and contract at the same rate when heated or cooled?

When you rack a wine from one container to another it doesn't change it's temperature significantly and as Sour_Grapes states even if it miraculously changed 10 degrees that would account for perhaps 1 tablespoon, not 10 ounces (or 20 times one tablespoon).

What we are talking about is when you rack a batch of wine from one carboy to another - folks are having situations where they find they are 1) Leaving 2-10 ounces behind and yet filling the new carboy. OR 2) Racking and leaving perhaps 4-6 ounces of wine (with sediment) behind and then needing to add 12 ounces or more of volume to top off a carboy. (My post above was with 3 gallon carboys.)