Purging

[Hazelwood Brewery]

Is that beer H, if so i take it you have a check valve on your gas line

Yes it is. I do have check valves but I don’t really fill to this level, I just took my eye of the ball earlier this year.

 

[Cheshire Cat]

Yes it is. I do have check valves but I don’t really fill to this level, I just took my eye of the ball earlier this year.

You can put an extra tap on the gas post and serve two drinks simultaneously.

 

[hoppyscotty]

There is a bit more headspace in that keg. I’ll get it to that stage, put the lid on then use a garden sprayer with ball lock attachment, open the keg PRV and push more starsan in until it squirts out of the PRV.

 

[DocAnna]

I’m sanitising and purging 4 kegs today. I thought I’d have a bit of fun and have deconstructed some of my other lines to set up as below, simultaneously purging and sanitising 4 kegs. Each has a gas to beer line linking them. The last keg has its prv open. Each keg had a little extra sanitiser it it to allow for losses in between and the last one is in a bucket to catch the overflow. Each one has had a couple of shakes while filling to coat the upper part of the keg.

 

[ssashton]

FWIW I used to use a flame above the keg and when it wouldn't stay alight I figured that was purged. However I was getting oxidation.

So I now fill the keg fully with warm water and 2 tablespoons of sodium percarbonate (AKA powered brewery cleaner). This gives it a PH of about 11 which will kill all neutrophils and acidophiles. It is brew safe and a lot cheaper than StarSan.

I also give it a clean with StarSan first, to kill any Alkaphile microorganisms.

Purging this way I have not had oxidation (plus closed transfer from FV).

 

[hoppyscotty]

I use sodium percarbonate as a steriliser than starsan as a sanitiser but for kegs I was wondering about using sodium metabisulphate which I believe is an oxygen scrubber but also is a sanitiser. Is this true? If so then I believe Sodium Metabisulphate is such an effective oxygen scrubber than you'd not need to totally fill the keg and could say half fill it and the SMB will scrub any oxygen in the headspace too? Is this the case?

 

[ssashton]

I use sodium percarbonate as a steriliser than starsan as a sanitiser but for kegs I was wondering about using sodium metabisulphate which I believe is an oxygen scrubber but also is a sanitiser. Is this true? If so then I believe Sodium Metabisulphate is such an effective oxygen scrubber than you'd not need to totally fill the keg and could say half fill it and the SMB will scrub any oxygen in the headspace too? Is this the case?

Sodium percarbonate and some water is so cheap it's not worth saving a little to not fill the keg. Beer is expensive in materials and time, just don't risk it.

 

[hoppyscotty]

Well not really thinking about saving money, SP is cheap as you say and I don't think starsan is particularly expensive either, but my thinking is that Sodium Metabisulphate is a positive and pro-active oxygen scrubber so instead of simply replacing the keg volume with sanitised water and replacing that volume with CO2, you take a water and SMB mix which is also sanitary, partially fill the keg leaving the SMB to actively scrub the oxygen. Not sure of the chemistry around it but feels better to me to have something that is going to proactively scrub the oxygen from the keg rather than just replace it.

 

[ssashton]

Well not really thinking about saving money, SP is cheap as you say and I don't think starsan is particularly expensive either, but my thinking is that Sodium Metabisulphate is a positive and pro-active oxygen scrubber so instead of simply replacing the keg volume with sanitised water and replacing that volume with CO2, you take a water and SMB mix which is also sanitary, partially fill the keg leaving the SMB to actively scrub the oxygen. Not sure of the chemistry around it but feels better to me to have something that is going to proactively scrub the oxygen from the keg rather than just replace it.

Ahh okay. I feel the other way, I trust completely replacing the air with water (then CO2) because I can physically see the water replacing the air, lol. Not sure I have the ability to test the absorption of oxygen by bisulphate? As I said above I used to use a flame in the top of the keg and when it didn't stay alight I thought it was purged, but it turns out that was not good enough.

How do they make those oxygen savaging bottle tops? Is that a bisulphate coating?

I don't think the idea is a bad one though. I'd just fill the keg fully with water and bisulphate leaving as small head as I can.

 

[ssashton]

After thinking about this I'm wondering if Sodium Percarbonate is a really bad idea for purging a keg. It's often sold as 'oxygen bleach' for laundry so it makes me wonder if it would be releasing oxygen in to the keg as it dissolves in the water?

Anyway I think the idea of using sodium metabisulfite might be a lot better after-all. I just did one keg that way with 5 campden tabs for the 20L. Not sure if that's over-kill or what?

 

[Branny]

I'm loving purging using fermentation gas and do it via the starsan full keg. If people want Uber cheap, wouldn't the cheapest be simply to attach the FV to the beer post (Co2 in) and then take a line off the gas post to vent (Co2 out).