Loosing the hops taste out of the brew

[Outback Brewery]

G'day everyone,
Long term follower but first post, hopefully someone can help and excuse the long post, Ive been searching with no result but i generally brew kit and kilo base then add hops and things to spice it up and it actually turns out really good, i either use 50l kegs or 19l kegs and a few stubbies and long necks, the one problem i have and i dont know if anyone else has come across is when i fill the kegs (size doesnt matter) then chill they taste great but come a month or so the hops flavour and smell drops off back to the basic kit brew which isnt the best lol, the stubbies are always perfect, the kegs are fine inside (no mould etc) and the lines are fine (although i dont wash them until i change the keg), strange thing also is when i change kegs during a party without flushing the lines the taste is back until another 3 or 4 weeks or so, it seems like it only happens once a keg has been tapped, do you think the beer is starting to go off or any other ideas? TIA Chris

 

[peteru]

Oxidisation. Invest in a spunding valve and pressure gauge. Set the spunding valve to about 180kPa for ambient temp of 20C. Prime the kegs at around 75% of the amount of sugar you would use for bottling, fill to about 90% and let the keg carbonate naturally at around 20C for a week. Remove spunding valve, fridge for a couple of days and enjoy. Do not connect to CO2 cylinder until the flow slows down.

 

[Outback Brewery]

Thank you peteru, ill give it a try, appreciate it