Z&N SS-60 / checking BBT carbonation level

[Supernaut]

Hello All,

Just about ready to purchase a carbonation meter. I've been researching the Zahm & Nagel device. I believe I understand how to use it (never have before) but I am curious - can it be used to measure the carbonation level in a "carbonating" tank?

I carbonate my beers by gently pushing the tank pressure up to 15 PSI with the carb stone and then holding it there for a few hours by bleeding a little pressure off the head space.

Now, when the tank is in this "steady state" any samples I try to pull from the sample valve are all foam. I believe this is due to the high pressure in the tank and the short length of the sample valve.

When the tank is in this "in-progress" state can the SS-60 be used to accurately measure its carbonation level? Or do I need to let the tank sit and calm down for a bit before taking a measurement?

It seems like folks use it to test in-progress carbonation levels - just trying to understand it fully before taking the leap and spending the cash on a Zahm & Nagel.

Thanks!

John

[Supernaut]

Yeah - I've considered that design and variations of it (barb + tubing + ball valve), mainly for filling growlers. I want accurate numbers for my carbonation levels, though.

[TL Services]

A pig-tail will help to reduce fobbing as it allows the pressure to drop over a long length, rather than just out of the tap.

You can make one quite successfully using a 3-4ft length of 1/4" tube and wrapping it around a broom handle or similar

For CO2 measurement it is important to have 'solid' beer ie. no gas bubbles as these will give rise to inaccurate results. This is why instruments like the Orbisphere, that use a flow of sample, have a needle-valve on the sample chamber outlet - to control back-pressure and thus ensure the beer in the chamber is 'solid'.

Other instruments, like the Anton Paar CarboQC, also use a flow controlled outlet for the same reason.

I haven't used the Zahm instrument much but have regularly used Zahm bottles where it was always a practiced hand to make sure they were filled properly..!

[Larry Doyle]

We used the zahm steel bottle for a million years at the big brewery. Like the man said you need a pig tail and then you are in business.

The Zahm bottle is simple. That's why its good. You have a gage and you have a thermometer and both are easily checked. Check the gage daily against a master gage. The thermometer won't change unless the mercury (or alcohol) separates and that's something you can see.

Eventually, our brewery switched over to a Gehaltameter to check bulk CO2. My experience was that one never knew if it was calibrated and the answers did not jive with our packaged samples which were still checked the old fashion way, using a piercing device that simply measured pressure and temperature.

The next step was to adjust the gehaltameter by putting a "fudge factor" in it so bulk and packaged CO2 would be in the same ballpark. This was pure idiocy. But everyone knows you can't argue with idiots because they drag you down to their level and then they beat you with experience.

For the umpteenth time: "KEEP IT SIMPLE STUPID!"

Don't know what they use now.

[TL Services]

Eventually, our brewery switched over to a Gehaltameter to check bulk CO2. My experience was that one never knew if it was calibrated and the answers did not jive with our packaged samples which were still checked the old fashion way, using a piercing device that simply measured pressure and temperature.

Strange that, 'cos the Gehaltemeter also uses pressure/temperature to derive CO2

Slightly...but only slightly...off subject, if anyone uses nitrogen in their beer for head stability, then none of the P/T meters will give good CO2 results as they can't separate the two gases.

As a rough order-of-magnitude for this, 2.5v/v of CO2 and 40ppm of N2 will give around the same pressure at 1 deg C, so using a P/T CO2 meter would give an error of 100%...

[Bbump22]

Hello All,

Just about ready to purchase a carbonation meter. I've been researching the Zahm & Nagel device. I believe I understand how to use it (never have before) but I am curious - can it be used to measure the carbonation level in a "carbonating" tank?

I carbonate my beers by gently pushing the tank pressure up to 15 PSI with the carb stone and then holding it there for a few hours by bleeding a little pressure off the head space.

Now, when the tank is in this "steady state" any samples I try to pull from the sample valve are all foam. I believe this is due to the high pressure in the tank and the short length of the sample valve.

When the tank is in this "in-progress" state can the SS-60 be used to accurately measure its carbonation level? Or do I need to let the tank sit and calm down for a bit before taking a measurement?

It seems like folks use it to test in-progress carbonation levels - just trying to understand it fully before taking the leap and spending the cash on a Zahm & Nagel.

Thanks!

John

John,

I've used the Z&N to successfully measure CO2 while carbonating beer.We flush the line with carbonating beer and adjust the flow rate so that beer is flowing out so that the sample is a quality sample to test.

Its a very common tool a lot of breweries use to measure the CO2.

Cheers,