Oxidation after first pour from tap

[GreenDrum]

Hey fellow homebrewers,

Can you help me solve this oxidation issue I've had for the past year?

Issue: My beer in the keg oxidizes after the first pint is poured. The first pint is perfect and has no hint of oxidation. About two days later, heavy oxidation has set in and the beer quickly deteriorates after that. That is why I believe it has to do with the tap or lines. After sitting for a week under pressure, if there was any oxygen left in the keg the first pint would taste slightly oxidized. Right?

Cleaning process: I've replaced the tap lines and I've cleaned both the keg, lines, and tap system with both PBW and line cleaner. Before kegging I clean the system with Star-San.

Kegging process: Once I realized that oxidation was my issue with kegging, I've been extremely careful with my process. First I fill the keg with star-san and push it out of the tap using CO2. This should create a good layer of CO2 when transferring. I then use an auto-siphon to transfer the beer to the keg making sure to fill at the bottom of the keg and create no splashing. I then seal the keg and purge it 8-10 times.

My next steps are to replace the tap, lines, and keg if I can't figure out the issue. Any input on what might be wrong would be greatly appreciated as it would save me a lot of time and money.

 

[bigdawg86]

Is it oxidation or could you have some nasties lurking in your tap? May be worth disassembling the tap to ensure it's clean

 

[Veets]

How do you clean your tap, lines, and connectors? Do you disassemble the connectors and tap with every cleaning?

If there's any doubt, maybe you have access to a picnic tap you can use on the next fresh keg? New line, thoroughly cleaned connector, and picnic tap. Hopefully that will tell you whether its's something after the keg or something upstream.

Otherwise, maybe you can explain more why you think it's oxidation only after the first pint is poured? Have you tried letting a fresh keg sit for a couple of weeks, and then taste? It could be that you have oxidation setting in from the get-go, and you're only noticing it after the first pint due to timing, and not because a first pint was poured.

I guess one other possibility could be your CO2 supplier. Do you have the ability to check with others who get their gas from the same place? Or, better yet, access to a different supplier?

 

[GreenDrum]

Is it oxidation or could you have some nasties lurking in your tap? May be worth disassembling the tap to ensure it's clean

I've disassembled it a few time and soaked it good with PBW. Might be a good idea to replace though. It looks like the inside is getting pretty worn out.

 

[GreenDrum]

How do you clean your tap, lines, and connectors? Do you disassemble the connectors and tap with every cleaning?

If there's any doubt, maybe you have access to a picnic tap you can use on the next fresh keg? New line, thoroughly cleaned connector, and picnic tap. Hopefully that will tell you whether its's something after the keg or something upstream.

Otherwise, maybe you can explain more why you think it's oxidation only after the first pint is poured? Have you tried letting a fresh keg sit for a couple of weeks, and then taste? It could be that you have oxidation setting in from the get-go, and you're only noticing it after the first pint due to timing, and not because a first pint was poured.

I guess one other possibility could be your CO2 supplier. Do you have the ability to check with others who get their gas from the same place? Or, better yet, access to a different supplier?

I like the picnic tap idea. You could also be right that the oxidation just hasn't set in yet and waiting only a week isn't long enough. I'll try that next time.

 

[bleme]

I've heard that cheap beer line can oxidize the beer left in the line. You could try tossing the first 2oz of a pour and see if it goes away. If that works, invest in a better quality line.