Minimising oxidation

[Coldspace]

In the quest to improve my beers, I've started doing my lagers in a keg king kegmenter which gives me near 100% sealed pressure ferment system! which I then transfer under pressure through my purged filter and into my purged kegs.

Now, this gives me a minimal risk of oxidation, I've never had much of an issue with oxidation but in the past my real hoppy pale and IPAs have aromas faded away fast in the keg, even after purging with co2.

I used standard fermenters this way, but as I only just started using the kegmenter , I've only used lagers. Like helles and other malt foward beers like octoberfest, Doppelbocks etc.

My first hoppy beer in my kegmenter will be this week a sort of India pale lager, as my kegmenter as a nice cake of s189 in it. I'll be keen to see the less risk of oxidation on this beer.

But, one flaw I've can't get rid of, is when you purge your cornies, it will take sooo much co2 to actually get all the o2 out, as the blanket effect everyone thinks will happen doesn't happen, the co2 just mixes up and blends into the kegs environment, yes the level will drop, but apparantly I read on a brew mag pro brewers in the US have measured it and the level stays surprisingly high even after several well purged gulps of co2. This also increases the risk of oxidation If you rock n roll the keg as you are then dissolving the o2 into the beer.
Now this is not really an issue with say a standard beer that will be consumed in weeks, but a big hop foward IPA , IPL, etc it may loose some quality.

One method some of the pro brewers do over there and prob here is fill the receiving tank/keg with water, push water out with the co2, this then ensures near total displacement of o2 with a co2 environment.

Apparantly this uses less co2 than some big keg purge flushes, and is so much better in ensuring an o2 free vessel.

Prob been abit anal here, but I'm doing everything else right so might as well try this method on mainly my big hoppy beers.
I'll fill my receiving cornies with water, co2 the water out at low pressure say 6 psi, when empty, pressure fill from my kegmenter which I have been doing. That way basically nill o2

Thoughts guys........

 

[manticle]

Any idea that improves beer is a good one and you're on a site where people measure pH and worry about 0.1-2 variance (rightly) so anal away, my friend.

 

[Coldspace]

Yeah,

Oxidation ruins hoppy aromas, especially when you want the keg to stay around awhile, I'll be giving this ago next keg up, but the Russian river brewery who do the famed Pliney the elder apparantly flush out water from receiving vessels with the co2 to keep the big aromas in tact, it's gotta work for our little back yard operations lol

I prob wouldn't worry too much on one of my more common beers here that get consumed fairly fast, but I do love my big aroma ales and lately will start experimenting with IPLs as well, so will employ no o2 risk factors .

Cheers

 

[manticle]

Also it sounds pretty simple to put in practice.

I'm presuming keg is filled to the top with water first? Easy enough to incoroprate into a cleaning regime, good to re-use/recycle the water.

 

[Coldspace]

Yes, they fill to top, pressure slightly with co2 which pushes all water out and leaves 100% co2 in there. Apparantly the tests prove that even some really big keg purges and flush with gas still leaves a lot of o2 behind because it's all just mixed up. But the water method works 100% and uses less gas.

For the sake of the odd nice hoppy beer I do which I love to have a couple of variants on tap but my lagers , mids etc get used way faster, so think this may help in prolonging the hoppy goodness which even a small amount of o2 can not hurt the beer as such but can scrub out fast that nice fresh aromas before even going half through a keg.

I'll give it ago , just was an interesting article

 

[nosco]

What happens if you leave the keg over night? Will the gases separate if given time? My method lately is to put Starsan in the keg the night before or after cleaning, fill with co2 and purge at the same time as normal. Then fill the keg down the liquid dip tube with the prv open so that the beer pushes the O2 and co2 out of the top of the keg. It works perfectly with just a nylon hose over the liquid post thread but its problematic using a disconnect on the keg post. Using a kegmenter would be perfect for this as you can push the beer down the lines with co2. Thats my theory anyway.

 

[nosco]

I waste enough water in brewing as it is so im not gonna try flushing out the o2 with water any time soon.

 

[Lyrebird_Cycles]

What happens if you leave the keg over night? Will the gases separate if given time?

No, quite the opposite: if you could manage to fill the bottom half of a keg with CO2 and the top with oxygen*, if you left it long enough they would diffuse into one another.

It's driven by simple probability: the motion of the molecules is random, the chance that a molecule will move from the area with more of one species to the area with less is therefore greater than the chance that one will move in the opposite direction.


* I did it this way around because CO2 is about 40% heavier than O2 in the same conditions.

 

[nosco]

I also assume that bubbles in Starsan with this method are co2 bubbles. No way to tell.

 

[nosco]

Also it sounds pretty simple to put in practice.

I'm presuming keg is filled to the top with water first? Easy enough to incoroprate into a cleaning regime, good to re-use/recycle the water.

I guess it wouldnt be that hard actually

 

[Futur]

I also assume that bubbles in Starsan with this method are co2 bubbles. No way to tell.

There can be no waste in doing this method. I have a premixed 25L container of starsan. I fill a keg with it and then use co2 to push it straight back into the original vessel.

 

[Coldspace]

Great idea futur, I'll do the same , good way to full santise everything, plus co2 perfection.

Love this site..

 

[buckerooni]

this thread has inspired me to get some RO water and starsan supply sorted! also had problems with oxygenated beers that were introduced as part of 'packaging'.

 

[mstrelan]

Does CO2 affect the StarSan at all? Assuming you're keeping it for a while after.

 

[Futur]

Does CO2 affect the StarSan at all? Assuming you're keeping it for a while after.

I very much doubt it, at the pressure used to purge the keg (5-20psi) and the amount of time it takes (~5 min), very little c02 would be forced into solution to even make contact with the starsan.

 

[nosco]

I have wondered about the gas that collects in the transfer hose with graviry feed. Is it co2 coming up from the keg? Probably not an issue if transering with co2 pressure.

 

[tugger]

Have you guys ever measured your oxygen content in a finished keg.

 

[Ferg]

I'm going to try the same thing with a NEIPA that I have in the fermenter currently. On top of that I got around to thinking about in-line carbonation at the same time. Basically use the same set-up that a lot of people use for in-line oxidation and bubble some C02 through there at the same time. The receiving keg would need to be pressurised to reduce foam build up during transfer with a spunding valve attached. In (my) theory any C02 that is expelled from the solution would force any O2 remnants out the valve while you may have a carbonated or at least partially carbonated beer. Did I mention I love gadgets?

 

[tugger]

That's the same method I use when filling bright tanks from fermenters at work.

 

[tugger]