need a favor: how deep in the carboy?

Hey, peeps...

Can I get a few of you guys to measure the height of the liquid level in a 6.5 gallon glass primary with 5 or 5.5 gallons of brew in it? If you could post the number of inches (or cm) and the volume of beer in it (if known fairly precisely)?

I would really appreciate this!

WHY I NEED THIS

I sitting here looking at my porter in the primary, and it just seems like there isn't enough there.

<insert your joke here about there 'never being enough' in the carboy>

I'm sure there is less than normal. Until recently, I went into the carboy via the bottling bucket (back when I cooled with ice) so I always had means of measuring how much top off water I needed.

I don't use the bucket anymore, and my carboys are not marked, so I have no accurate way to measure how much is in the primary when topping off. When I brewed my IPA, I never even thought about it because I had gotten used to always using 6 gallons of water in the process and ending up with about 5.5 in the primary. I used 6 gallons with the IPA and it looked right in the primary, so I never even thought about the fact that I did not measure anything.

<I know... I'm rambling... had a few...>

Anyway, the porter looks low. WAY low. I used 6 gallons, but there just doesn't seem to be the right amount there.

I can't use my other two primaries as reference because (a) one of them is bordering on antique and it not the standard shape as all other 6.5 gallons I have seen and (b) the other one is at my parents house.

thanks!
-walker

Can't measure because I am at work but I do know that I was told by one of the guys at my LHBS that there is more variation in the volume between different batches of carboys than you would think. Might not be real accurate.

Different carboys are going to vary. Not all mfg's manufacture a 6 gallon carboy to the same dimensions. Or a 5 gallon for that matter.

Looks like my 6.5 gal carboy is at 11.75 inched from the floor to the 5 gal mark. I had drawn a line on my carboy at exactly 5 gal with a sharpie when I first got it after pouring in 5 gal from empty spring water jugs. The 6.5 gal carboy I have looks to be about 1 foot in diameter. Hope that helps walker.

prowler, mindflux...

humor me.

-walker

you see... I'm being a BIT lazy here. I could measure the secondary and liquid level and calculate the volume, and figure it out that way...

but that would be math....

and I'm off duty, so I refuse to do math right now.

edit: ok, I admit it. I just realized I could figure this out myself. nevermind.

-walker

Just measured my 6 1/2 gallon carboy. 5 gallons is at 11 3/4". 6 is right at 14".
(I've got sharpy marks for every gallon)
Has anyone figured out a way to mark the gallons on a carboy in a way that won't come off?

Paint pen works well. I just use electrical tape. No prob!

Some people etch their glass too.

RichBrewer said:

Has anyone figured out a way to mark the gallons on a carboy in a way that won't come off?

Click to expand...

Glass cutter. Abrasive stone. Hydrofluoric acid. Whatever, that's easy.

Neglecting the top "dome" part, the volume of a cylinder is V=pi*(d/2)^2*h, where d is the diameter of the cylinder and h is the height. Solve for h; that's h=V/(pi*(d/2)^2). You can't just plug in gallons as gallons have no units relating to feet or inches...convert the volume into cubic inches if your carboy diameter is in inches. From <a href="http://www.google.com/search?client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial_s&hl=en&q=5+gallons+to+cubic+inches&btnG=Google+Search">a google search</a>, I know that 5 gallons is 1155ci. 1 gallon is 231ci.

So, to find the height of one gallon in your carboy where the inside is roughly cylindrical, use h=231/(pi*(d/2)^2). Remember, the height and diameter are based on the carboy's INSIDE dimensions, so you might have to estimate the thickness of the carboy's walls and subtract that (twice) from the diameter of the carboy to find the inner diameter. Take into account the bottom's thickness as well.

As for the top volume, I don't know about that. You could probably estimate it with a fraction of a volume of a sphere or with the volume of a cone or something if it matters to you that much, but it would be a pain to mark volume on the top part of the carboy anyway.

I use my fiance's nail polish to mark my carboys.

i always mark my carboy 12.5 inches from the bottom. (with a piece of tape). and i usually end up with +5 g. after racking to the secondary. i measured 5 g. with h20 once and it came out to 12 inches (how convienient), im assuming there is some variation among carboys but i think 11-12 inches is around about 5 g's.

RichBrewer said:

Just measured my 6 1/2 gallon carboy. 5 gallons is at 11 3/4". 6 is right at 14".
(I've got sharpy marks for every gallon)
Has anyone figured out a way to mark the gallons on a carboy in a way that won't come off?

Click to expand...

I cleaned the side of the carboy w/ rubbing alch, then marked the carboy with a black sharpie and placed good quality clear packing tape over the marking. Looks like a little laminated square on the side of the carboy. I have not had a problem with it coming off.