dOs pick up with Meheen M6

[beer_gorilla]

Anyone have any tips/trick/etc for figuring out why our Meheen M6 filler is suddenly picking up a bunch of dO2?

I know the dO2 is coming from the headspace (check of package w/ and w/o shaking). The beer is foaming up as usual and we are capping on foam. We tried varying the filling rates and while we could achieve a little decrease, it really didn't make much difference. So my thoughts are that either the filler is having an issue w/ the purge/evac or our CO2 is entraining air somewhere along its course to the Meheen (dO2 pick up is not concurrently being seeing elsewhere).

Any tips would be appreciated.

Beers!

[AT-JeffT]

We use a 6 head meheen as well and have just started using a Zahm 7000 to measure headspace airs. We've gotten it down from 7 to 3.5ml. Though I've heard that 1ml or .5ml is ideal. I'm also interested in what we can do to lower headspace airs.

[TL Services]

From your post, I'd certainly suggest looking at both purge and your CO2 supply. If the beer is coming in at low DO2 (ie. unshaken package result) then any increase can only be coming from elsewhere.

You can check the CO2 by gently flowing the gas through a DO2 meter - what you need is a gentle flow from the supply (ie. just cracked open) and the meter's flow valve wide open to avoid pressure build-up in the flow chamber.

To get a guide for the amount of oxygen, pro-rata the displayed result, because 20% oxygen would read around 9ppm on a dissolved-phase meter:

20% reads 9ppm
2% reads 0.9ppm (=900ppb)
0.2% reads 0.09ppm (=90ppb)
etc.

Hope that helps!

[lhall]

With our old 2001 Meheen six head, without pre-evac, we could get between 1.0-2.0 ml air using the Zahm Nagel headspace tool. There was always one head that wouldn't foam as well as the others.

You might check that you don't have a faulty poppet valve for your CO2 or your pre-evac circuit. If a diaphragm is leaking you might be getting compressed air in. I think the newer Meheens create the vacuum using a venturi, right? Might check that the circuits of the venturi aren't blocked or fouled, and that you are actually getting vacuum.

[BrewinLou]

Yep, I agree with Linus, make sure your eductors(sp) are clear.

[beer_gorilla]

Thanks for the info so far...

We will be looking at it with some of your suggestions.

thanks and beers,

jim

[beer_gorilla]

Other sources can be the CO2 source which should be checked for purity and be beverage grade.

Thanks, Dave. We aren't seeing dO2 increases anywhere else, so I am pretty confident our CO2 is fine at the source.
Will pass this info (along with the other suggestions) to our crew.

beers,

jim