my kegs have less hop flavour

[Moog]

Since I started kegging my beer, I've noticed a drop in hop flavor.
I'm wondering if somehow my kegs are stripping this flavor, do I need to fully clean and decontaminate them?
I've only kegged IPA's and DIPA's and they have all seemed lacking in hop flavor, I usually bottle 4 or 5 beers as the batch is normally too big.
The bottled beers seem better than the kegs.
To clean the kegs, I fill with a kettle of boiling water, shake it all about, this creates a fair bit of pressure, then I vent some boiling water through the beer post by opening the valve with something sharp, then I tip the keg upside down, and vent through the gas post, and relief valve.
Then I let out the pressure, and empty.
Before I re-fill with beer, I do this again, then put a couple of litres of starsan in, swill well, empty, and then, in goes the beer.
I put the gas on, vent off the air, then force carb.
Sometimes i'll naturally carb in the keg, also, sometimes I fully strip and clean the posts.

Is there a reason that the keg could rob my hop flavor? What would cause it?
What is the best way to fully clean my kegs?

Any help and suggestions appreciated..

 

[mtb]

O2 in your keg sounds like the culprit. When you keg the beer are you purging with CO2 beforehand? Reading your method above it seems that you're purging AFTER adding the beer. I'd be purging before that.

 

[Dan Pratt]

yes O2 is the culprit, sounds like the cleaning is in order.

You should fill and purge your keg with C02 before filling with beer to avoid O2 pickup. the more O2 the beer has contact with the quicker the hop character will diminish.

 

[Moog]

ok, thanks, so if I fill & purge the empty keg with CO2 through the beer post, as I do when, force carbing, then take the top off the keg, fill with beer, and do as before.
Will the CO2 stay sat in the keg?.
I know some people use pressure to transfer, but this will require changing my setup a bit before I could do that.

 

[wereprawn]

ok, thanks, so if I fill & purge the empty keg with CO2 through the beer post, as I do when, force carbing, then take the top off the keg, fill with beer, and do as before.
Will the CO2 stay sat in the keg?.
I know some people use pressure to transfer, but this will require changing my setup a bit before I could do that.

Yep, if you can't do a closed transfer, what you propose is much better than no purge at all, although you won't need as much pressure to purge as you would if force carbing. Just enough to displace the air. Be gentle when removing the keg lid and still try to avoid splashing.

 

[mtb]

The almost completely O2-free method of purging the keg is to fill to the brim with sanitiser or sanitised water, and then push it out the beer post with CO2. If you don't want to go to that extent of effort (and without a closed transfer there may not be any point), your method is fine.

 

[mattyh77]

You don't need pressure to close transfer.
I purge my keg with CO2, the just put a liquid disconnect onto the end of the hose and place the other end into the tap of the fermenter. Make sure you release the pressure in the keg prior to opening the tap or you'll get all the CO2 rushing back into the fermenter.
Once you open the tap release the PRV and let it gravity feed into the keg. Takes a little longer but at least I know there is no O2 getting into the keg.

 

[Moog]

that sounds a good idea, but how do you know when its full?
surely you need to stop and allow a small headspace.

 

[mtb]

that sounds a good idea, but how do you know when its full?
surely you need to stop and allow a small headspace.

I use scales - https://www.ebay.com.au/itm/Kitchen...hash=item41ce43b9a4:m:m5PlzzVq7W3NeON7UL1Ydww
I disconnect the transfer line when I hit 18.5kg. There are minor variations in weight depending on gravity of the beer but there are tools online to calculate that.
These scales are also handy for weighing out your grain bill in one big bucket; add one malt to required weight, zero out, repeat for the next malt, etc. Also many of them have batteries so you can move them about as needed.

 

[Coodgee]

on a humid day you can see the liquid level from the condensation on the outside. Or you can just fill to the foam starts coming out the PRV and then drain a pint or two to celebrate a full keg. Once you've done it a few times you get a feel for it.

 

[mattyh77]

I cold crash so I can see the condensation coming up the side of the keg, otherwise out the problem the drain a glass or two.

 

[Lionman]

Do you need headspace in the keg?

What is the impact on carbonation time for a completely filled keg?

 

[mtb]

I assume it's a matter of surface area that is in contact with pressurised CO2. If you fill until beer comes out the gas post, the gas diptube is probably submersed.. not sure how much slower that'd be to carbonate but I guess a fair bit.

Someone needs to come science this.

 

[Moog]

ok i'll try the beer post method under gravity next time and see how I go, I've got bathroom scales but I don't think they'd be sensitive enough.
I always cold crash, and I've noticed the condensation before.
I guess if you're using gravity, you need to avoid the incoming air from disturbing the layer of CO2 on top of the beer, or you'll just get oxidization from there as well.

 

[Lionman]

ok i'll try the beer post method under gravity next time and see how I go, I've got bathroom scales but I don't think they'd be sensitive enough.
I always cold crash, and I've noticed the condensation before.
I guess if you're using gravity, you need to avoid the incoming air from disturbing the layer of CO2 on top of the beer, or you'll just get oxidization from there as well.

Do you mean air into the fermenter? I wouldn't worry about that, your drawing beer from the bottom and there will always be some left in the fermenter, I dont think this will pose a risk really.

 

[Black Devil Dog]

I assume it's a matter of surface area that is in contact with pressurised CO2. If you fill until beer comes out the gas post, the gas diptube is probably submersed.. not sure how much slower that'd be to carbonate but I guess a fair bit.

Someone needs to come science this.

I always fill mine until beer comes out the gas disconnect.

Once full, I purge a few times with co2, then connect the gas and set the regulator to 3 bar and leave it for 24 hours.

Works fine, but you'd need to have either a one way check valve, or one of these. I have the latter.