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General Category => Kegging and Bottling => Topic started by: pointyskull on January 15, 2018, 01:33:08 AM

Title: Oxidized DIPA -again...
Post by: pointyskull on January 15, 2018, 01:33:08 AM
My second kegged DIPA is suffering what appears to be oxidation.
Keg was purged pre-fill, no splashing on transfer.

Here's my question:
I have been 'slow' carbing (11-12 psi over a couple of weeks) my homebrew kegs, as they share a C02 tank with some commercial kegs.

Question:
Does force carbing do anything to eliminate the potential for oxidation?
I know I am clutching at straws, but just trying to see if there is any homebrewer research on this.

I am frustrated, and googling like a banshee.
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 15, 2018, 01:49:23 AM
Quick vs. slow carbing won't change potential for oxidation; but if it takes a couple of weeks for symptoms to appear, time you're spending carbing, you'd at least get a week or so of drinking fresher tasting beer in.  That's all. Oxygen exposure (if you're sure that's the problem) is happening somewhere upstream in your process.
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 15, 2018, 02:24:08 AM
^^^^
Just another thought as you trace the problem: you could still have oxygen pickup at kegging.  You say keg was purged, but if you mean you put on gas and "burped" the PRV a few times, there was lots of O2 in that keg.  The only sure way to purge is to fill to the brim with liquid (e.g. sanitizer) and push it all out with CO2.  There was a thread recently on the forum where a member posted calculations on "purging" by burping the PRV and your mind would reel at the number of cycles it would take!  You're also drawing air into the fermentor as you siphon beer out (if that's what you do) so you might search here on the forum for threads on "closed transfers." I've just gone that route.
Title: Re: Oxidized DIPA -again...
Post by: pointyskull on January 15, 2018, 02:35:33 AM
Thanks, Robert!

What psi do you use to do the sanitizer purge with C02?
 
fwiw the beer tasted great pre-siphon, but I will look into closed transfers, too.

I will investigate...
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 15, 2018, 02:49:03 AM
Psi doesn't matter, whatever will get liquid out.  You'll know liquid replaced air, and CO2 replaced liquid.  I say don't waste gas pressurizimg the keg too high when you'll just release it to add beer!

If it tasted great out of the fermentor, I bet you're on the right track here.  This point in the process seemed to be my Achilles heel. Purging the keg is probably the big problem, because air drawn into the fermentor is only making contact at the still surface.  But it's really easy to do a closed transfer (a carboy cap based rig to push low psi gas in and a racking cane leading to a QD to your keg) and if you like IPA, well, those hops sure do suffer from oxidation don't they! (Your LHBS has probably already helped others assemble the bits for closed transfer.)
Title: Re: Oxidized DIPA -again...
Post by: klickitat jim on January 15, 2018, 03:00:04 AM
Caution if using fermenters that don't play well with pressure. Like glass carboys..
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 15, 2018, 03:05:17 AM
Caution if using fermenters that don't play well with pressure. Like glass carboys..
ABSOLUTELY! When I say "low psi" I mean like 1 or 2.  I elevate my carboy above the keg, so I just need to apply enough gas to in effect start a siphon and then replace the volume of the draining beer.  It's slow but O2 free.
Title: Re: Oxidized DIPA -again...
Post by: denny on January 15, 2018, 04:47:41 PM
Thanks, Robert!

What psi do you use to do the sanitizer purge with C02?
 
fwiw the beer tasted great pre-siphon, but I will look into closed transfers, too.

I will investigate...

These links might help....https://www.experimentalbrew.com/experiments/great-purge-does-full-liquid-purge-keg-protect-hop-aroma-better

https://www.experimentalbrew.com/purging-keg-etc-etc-etc
Title: Re: Oxidized DIPA -again...
Post by: narcout on January 15, 2018, 06:40:33 PM
Question:
Does force carbing do anything to eliminate the potential for oxidation?

If anything, it increases it. 

https://tapintohach.com/2013/12/02/how-the-purity-of-injected-carbon-dioxide-affects-the-oxygen-concentration-of-beer/
Title: Re: Oxidized DIPA -again...
Post by: The Beerery on January 15, 2018, 06:47:11 PM

Here are the maths

(https://www.homebrewtalk.com/forum/attachments/ppm-o2-after-purge-chart-png.402030/)

(https://www.homebrewtalk.com/forum/attachments/ppm-o2-after-purge-chart-2-png.383437/)

You can see it's much more efficient to use sanitizer and push it out (10-12psi). Also trimming your gas diptube flush with the top wall of the keg and overfilling the keg in a closed transfer will be your best bet.
Title: Re: Oxidized DIPA -again...
Post by: nbarmbrewer on January 15, 2018, 09:58:35 PM
Remember heat speeds up oxidation or maybe your hops are oxidized.
Title: Re: Oxidized DIPA -again...
Post by: klickitat jim on January 15, 2018, 10:09:19 PM

Here are the maths

(https://www.homebrewtalk.com/forum/attachments/ppm-o2-after-purge-chart-png.402030/)

(https://www.homebrewtalk.com/forum/attachments/ppm-o2-after-purge-chart-2-png.383437/)

You can see it's much more efficient to use sanitizer and push it out (10-12psi). Also trimming your gas diptube flush with the top wall of the keg and overfilling the keg in a closed transfer will be your best bet.
I'd be curious to see what 5, 10, and 15 seconds of 15psi on the out post would be.

Trimming the gas post... why haven't I thought of that?
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 15, 2018, 10:27:19 PM

Here are the maths

(https://www.homebrewtalk.com/forum/attachments/ppm-o2-after-purge-chart-png.402030/)

(https://www.homebrewtalk.com/forum/attachments/ppm-o2-after-purge-chart-2-png.383437/)

You can see it's much more efficient to use sanitizer and push it out (10-12psi). Also trimming your gas diptube flush with the top wall of the keg and overfilling the keg in a closed transfer will be your best bet.
I'd be curious to see what 5, 10, and 15 seconds of 15psi on the out post would be.
I've been looking over some past threads on purging.  It's been mentioned several times that there may be info on purging with a flow from the bottom, but nobody's posted a link. Anybody please?
  (Liquid still seems to me the surest thing.  Dalton' s Law and all.)
Title: Re: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 12:12:08 AM
(https://uploads.tapatalk-cdn.com/20180116/2100ef352876c32d5cc3d20ee4cb108a.jpg)

Close to full oxygen when just flowing in. Gases don’t stratify, they mix.


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Title: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 12:15:42 AM

Here are the maths

(https://www.homebrewtalk.com/forum/attachments/ppm-o2-after-purge-chart-png.402030/)

(https://www.homebrewtalk.com/forum/attachments/ppm-o2-after-purge-chart-2-png.383437/)

You can see it's much more efficient to use sanitizer and push it out (10-12psi). Also trimming your gas diptube flush with the top wall of the keg and overfilling the keg in a closed transfer will be your best bet.
I'd be curious to see what 5, 10, and 15 seconds of 15psi on the out post would be.
I've been looking over some past threads on purging.  It's been mentioned several times that there may be info on purging with a flow from the bottom, but nobody's posted a link. Anybody please?
  (Liquid still seems to me the surest thing.  Dalton' s Law and all.)


You mean like this?

“So, what happens if instead of doing pressurize/vent cycles, we flow CO2 into a vessel that originally contains air?  Does the flow improve the dilution and removal efficiency of O2 compared to the cyclic process?  We can argue that if the CO2 inflow is fast enough that CO2 comes in faster than it can mix with the air, then it could form a sort of gas piston that would push air ahead of it towards the vent, and that this would push out more O2 per volume of CO2 than if complete mixing of incoming CO2 and existing gas occurred (as it does in the pressurize/vent case.)

The best case for non-mixing of CO2 and headspace would be if there were absolutely no internal "air" currents, such that the only mixing of CO2 with headspace gas would be via diffusion.  So the question comes down to: Is the linear CO2 flow rate faster than the diffusion velocity of CO2 in air? If the CO2 flow rate were much faster than diffusion, then mixing would be limited, and continuous flow would be more efficient than purge/vent.  If CO2 flow rate were much slower than diffusion, then gases would be mostly mixed, and continuous flow would not be any more efficient than pressurize/vent.  If the flow rate and diffusion rates were of the same order of magnitude, then there would be significant, but not complete, mixing, making this the most complex scenario to analyze.

To start we need to get an estimate of the diffusion velocity of CO2 in air.  If we limit our analysis to one dimensional flow (say from bottom to top of a keg, uniform velocity across the width), things will be much simpler, but still valid.  Fick's first law of diffusion is (ref: https://en.wikipedia.org/wiki/Diffusion (https://en.wikipedia.org/wiki/Diffusion)):[indent]Flux = -D * (ΔConc / ΔDist)
Where Flux is in mass/area-time,
D is the diffusion coefficient, and
ΔConc / ΔDist is the concentration gradient[/indent]If we divide Flux [mass/area-time] by density [mass/volume] we get linear velocity [dist/time] which is what we are looking for.

The diffusion coefficient for CO2 in air is about 0.15 cm^2/sec (ref: http://compost.css.cornell.edu/oxygen/oxygen.diff.air.html (http://compost.css.cornell.edu/oxygen/oxygen.diff.air.html))  Now if we make some assumptions about gradients we might encounter, we can estimate a linear CO2 flow rate due to diffusion.  We will use approximate numbers for simplicity, since we are only looking for order of magnitude estimates of velocity.

A corny keg has a volume of about 20 L or 20,000 cm^3, and a height of about 55 cm, leaving a cross sectional area of about 20,000 cm^3 / 55 cm = 364 cm^2.  The density of CO2 at STP is about 2 g/L or 0.002 g/cm^3 (ref: http://www.engineeringtoolbox.com/gas-density-d_158.html (http://www.engineeringtoolbox.com/gas-density-d_158.html).)  If we assume 2.5 cm of pure CO2 at the bottom of the keg, and 2.5 cm of air at the top of the keg, and a uniform concentration gradient from the bottom to the top, the CO2 gradient becomes:[indent]ΔConc / ΔDist = (0 - 0.002 g/cm^3) / 50 cm = -4.0e-5 g/cm^4[/indent]The CO2 flux becomes:[indent]Flux = -D * (ΔConc / ΔDist) = -0.15 cm^2/sec * (-4.0e-5 g/cm^4) = 6.0e-6 g/cm^2-sec[/indent]And finally the linear velocity of CO2 due to diffusion is:[indent]CO2_Diffusion_Velosity = CO2_Flux / CO2_Density = 6.0e-6 g/cm^2-sec / 0.002 g/cm^3 = 0.003 cm/sec[/indent]



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Title: Re: Oxidized DIPA -again...
Post by: BrewBama on January 16, 2018, 12:16:50 AM
Gases don’t stratify, they mix.

Will someone please tell the AHA this ^^^


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Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 12:19:52 AM
(https://uploads.tapatalk-cdn.com/20180116/2100ef352876c32d5cc3d20ee4cb108a.jpg)

Close to full oxygen when just flowing in. Gases don’t stratify, they mix.


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Thanks, that's what I've always assumed (Dalton again) but never saw it quantified.  Hey, you probably have this covered too:  How much oxygen is introduced by being dissolved in the small residue of sanitizer in the keg?  I've never seen numbers on that either.
Title: Re: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 12:20:09 AM
Gases don’t stratify, they mix.

Will someone please tell the AHA this ^^^


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I have tried to tell everyone but no one listens!


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Title: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 12:22:18 AM
Fermentation generates nearly 25x the amount of co2 in relation to the wort volume. With some simple fittings you can route your fermentation generated PURE co2 though the keg it is going into. Effectively purging the keg perfectly. Bonus points for using it to purge the lines you use to transfer. Extra bonus points if you use spunding as well.

Clean and sanitize keg as normal, empty, then..

Fermenter out to liquid out on keg
Keg in to blow off bucket (or more kegs)

To get the same level of purge as this, you would have to fully pressurize the keg and fully release it at 25psi at least 20 times.. thats a lot of waster co2 out of your bottle when fermentation can do it for you effortlessly.

If you have blow off you can add another jar inline from the fermenter out to the liquid out. You would then have a tube from the fermenter below the sani level and the tube going to the liquid out as high as possible in the sealed jar.



[youtube]X9NdErVUnyQ[/youtube][/quote]


(https://uploads.tapatalk-cdn.com/20180116/0fddefac86abfa1c090f7d996748a30d.jpg)

“The reaction for fermentation of maltose is:[indent]Maltose + H2O --> 2 Dextrose --> 4 Ethanol + 4 CO2[/indent]Maltose has a molecular weight of 342.30 g/mol and CO2 has a molecular weight of 44.01 g/mol, so each gram of maltose fermented generates 4 * 44.01 / 342.3 = 0.5143 gram of CO2.  So, if we determine how much sugar we ferment over what period of time, we can calculate how much CO2 we created and calculate an average flow rate over the cross section of a keg.

Let's work an example assuming 20 L of wort with an OG of 1.050 that achieves 80% apparent attenuation over a four day fermentation.  First we have to determine how much sugar we started with.  An SG of 1.050 is equivalent to 12.39°Plato, or 12.39% sugar by weight.  To convert SG to plato use the following formula (ref: https://en.wikipedia.org/wiki/Brix (https://en.wikipedia.org/wiki/Brix)):[indent]°Plato = -616.868 + 1111.14 * SG - 630.272 * SG^2 + 135.9975 * SG^3 @ 20°C[/indent]Water at 20°C has a density of 0.9982 kg/L, so the weight of 20 L of wort @ 1.050 is:[indent]20 L * 1.050 * 0.9982 kg/L = 20.96 kg[/indent]This wort is 12.39% sugar by weight, so the weight of sugar is 2.597 kg.  At 80% apparent attenuation, this beer would have an FG of 1.010, or 2.561°Plato.  Since the presence of alcohol affects the SG the actual attenuation of the beer is lower (the final °Plato is higher), we must correct the final °Plato using the Balling approximation (ref: https://byo.com/hops/item/408-calculating-alcohol-content-attenuation-extract-and-calories-advanced-homebrewing (https://byo.com/hops/item/408-calculating-alcohol-content-attenuation-extract-and-calories-advanced-homebrewing)):[indent]Real_Final_°P = Apparent_Final_°P * 0.8114 + Original_°P * 0.1886[/indent]And, plugging in the numbers for our example:[indent]Real_Final_°P = 2.561 * 0.8114 + 12.39 * 0.1886 = 4.415°P[/indent]Thus the finished beer contains 4.415% by weight of sugar, which works out to:[indent]Final_Sugar_Weight = 20 L * 1.010 * 0.9982 kg/L * 0.04415 = 0.890 kg[/indent]The total sugar fermented works out to:[indent]Fermented_Sugar_Weight = 2.597 kg - 0.890 kg = 1.707 kg[/indent]And the total weight of CO2 created works out to:[indent]CO2_Weight_Created = 1.707 kg_Maltose * 0.5143 kg_CO2/kg_Maltose = 0.878 kg or 878 g of CO2[/indent]Since CO2 has a density of about 2 g/L, we created about 439 L or 439,000 cm^3 of CO2.

If we push our CO2 through the keg at a constant rate over a four day fermentation, the flow rate of the CO2 over the 364 cm^2 cross section of the keg works out to:[indent]
CO2_Velocity = 439000 cm^3 / (4 days * 24 hr/day * 3600 sec/hr * 364 cm^2) = 0.0035 cm/sec[/indent]
Damn, that works out almost the same as our diffusion velocity of 0.003 cm/sec.  So, we are in the complex, hard (i.e. infeasible) to analyze regime of relative flow rates.  So, what do we do now?  Well, we punt, and do the worst case analysis which would assume that we get no O2 removal assist from the sweeping action of the bulk CO2 flow.  As a result of doing this our residual O2 levels will be less than we calculate, so we will have a built in safety factor.

So, the answer to our first question is: Yes, the bulk CO2 flow probably helps sweep out more O2 than do simple pressurize/vent cycles, but the analysis is too difficult, so we'll just ignore the flow sweep effect, and end up with a pessimistic estimate of our final purged keg O2 levels (i.e. things will actually be better than the calculations show.)

Second question: What's the worst case O2 levels left in a keg purged with the output of an active fermentation?

So, just how do we attack a continuous slow purge flow analytically?  Assume a tube runs from the fermenter to the keg liquid post, and an airlock is fitted to the keg gas post. Then every time the airlock bubbles you lose a small volume of the current gas mix (which we are assuming is homogeneous) from the keg and fermenter headspace.  Let's call this volume "ΔV", and the total volume of the fermenter headspace, keg, tube, etc. "V".  Furthermore, let's call the current concentration of O2 in V "C".  We then have the following:[indent]Total O2 in V before bubble = C * V
O2 lost to bubble = C * ΔV
Total O2 in V after bubble = C (V - ΔV)
Concentration of O2 in V after bubble = C * (V - ΔV) / V[/indent]If C[0] is the concentration of O2 initially, then after "N" bubbles, the current concentration of O2 is:[indent]C = C[0] * ((V - ΔV) / V)^N[/indent]For V = 25 L and ΔV = 0.0001 L (0.1 mL), (V - ΔV) / V = 0.9999960.  We're not getting much purging action per bubble; this doesn't look very promising yet.

So, where will we end up at the end of the example fermentation above?  Well, we generate 439 L of CO2 from fermentation, and if we divide that into 0.0001 L bubbles, we produce a total of 4,390,000 bubbles.  If we plug that into our formula above, and start with 210,000 ppm of O2 in V, then we have:[indent]Final O2 Conc = 210000 ppm * ((25 L - 0.0001 L) / 25 L)^4390000 = 0.005 ppm[/indent]Believe it or not, we reduce the O2 concentration from 21% by volume to 5 parts per billion by volume!  :smack: :ban: :ban: :ban: Talk about the power of compounding!

We can only conclude that using the output of a reasonable size fermentation can very effectively purge a keg of O2.


We love to discuss this and other advanced topics our forums.  Link in signature.  You will see many active members from here over there. 

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Title: Re: Oxidized DIPA -again...
Post by: klickitat jim on January 16, 2018, 12:51:48 AM
I don't know, you lost me.

What I'm talking about would basically resemble a large blichmann beer gun, which many people seem to trust. Only I stead of a bottle it's a keg. CO2 pushed into bottom of empty keg, with prv open for x amount of time, then fill. I'm just curious what the measured DO numbers are, if anyone has measured. Not trying to say anything about which is better... obviously pushing sanitizer out would seem to be unbeatable. But what if a brewer couldn't do that for whatever reason. Pure curiosity. It seems like it has to do a better job than CO2 into the short tube IN and out the prv right next to it...
Title: Re: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 12:56:36 AM
I don't know, you lost me.

What I'm talking about would basically resemble a large blichmann beer gun, which many people seem to trust. Only I stead of a bottle it's a keg. CO2 pushed into bottom of empty keg, with prv open for x amount of time, then fill. I'm just curious what the measured DO numbers are, if anyone has measured. Not trying to say anything about which is better... obviously pushing sanitizer out would seem to be unbeatable. But what if a brewer couldn't do that for whatever reason. Pure curiosity. It seems like it has to do a better job than CO2 into the short tube IN and out the prv right next to it...


It won’t work, just like the blichmann doesn’t  work (DO levels too high).  Obviously IT WORKS but not in regards to lowering DO.  Gas laws are a bia. 


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Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 12:57:29 AM
I don't know, you lost me.

What I'm talking about would basically resemble a large blichmann beer gun, which many people seem to trust. Only I stead of a bottle it's a keg. CO2 pushed into bottom of empty keg, with prv open for x amount of time, then fill. I'm just curious what the measured DO numbers are, if anyone has measured. Not trying to say anything about which is better... obviously pushing sanitizer out would seem to be unbeatable. But what if a brewer couldn't do that for whatever reason. Pure curiosity. It seems like it has to do a better job than CO2 into the short tube IN and out the prv right next to it...
Yeah, it's a little counterintuitive when you look at the proximity of the in and out.  But the point is the gases will always fully mix.  You won't be just pushing C02 in the bottom and lifting 02 out the top.  So a continuous flow is least efficient.  Beerery's saying who cares if you have all the CO2 in the world from a fermentation.  If you're buying the stuff....
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 01:11:25 AM
Still wondering how much DO is introduced in the bit of sanitizer that remains in the keg.
Title: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 01:33:42 AM
Still wondering how much DO is introduced in the bit of sanitizer that remains in the keg.


Well it’s variable.  How much sanitizer? What temp water? How much DO in the water (8-12ppm). It would be easy enough to figure out.  Figure fermenting beer is sub 10ppb.  Say it’s an oz( .03 liter) and say the water is 10ppm( or 10000ppb) So then is straight math of 20l batch of 10ppb and .03 of 10000ppb.    What’s that like 15ppb on the sani and 10ppb on the main for 25ppb total?  Check that math I just quickly ran though it here on my phone. 


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Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 01:42:04 AM
Still wondering how much DO is introduced in the bit of sanitizer that remains in the keg.


Well it’s variable.  How much sanitizer? What temp water? How much DO in the water (8-12ppm). It would be easy enough to figure out.  Figure fermenting beer is sub 10ppb.  Say it’s an oz( .03 liter) and say the water is 10ppm( or 10000ppb) So then is straight math of 20l batch of 10ppb and .03 of 10000ppb.    What’s that like 15ppb on the sani and 10ppb on the main for 25ppb total?  Check that math I just quickly ran though it here on my phone. 


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Yeah, that's kind of what I was coming up with (on my phone too) but thanks for confirming, I  know you have a better grasp of this! My takeaway is: my biggest risk is in the purity of the CO2 itself, especially force carbing to 2.6v/v.  But that's one thing I can't do anything about, at least for now. Purging with sani and closed transfers I've got covered.  Wonder if some sort of inline CO2 "scrubber" exists.
Title: Re: Oxidized DIPA -again...
Post by: klickitat jim on January 16, 2018, 01:45:24 AM
I buy mine. A 20lb refill is about the same cost of one steelhead plug.
Title: Re: Oxidized DIPA -again...
Post by: klickitat jim on January 16, 2018, 01:47:26 AM
I can't do the sanitizer push. Just can't imagine leaving a pint of no rinse iodophor in my beer. Sorry, not happening. I prefer cardboard flavor over iodine
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 01:50:49 AM
I can't do the sanitizer push. Just can't imagine leaving a pint of no rinse iodophor in my beer. Sorry, not happening. I prefer cardboard flavor over iodine
Unless you have trimmed dip tubes, it's probably more like half an ounce or thereabouts.
Title: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 01:56:58 AM
Come on guys get out of your box!  Trim gas dip tube flush.  Push out everything you can.
Remove all connectors.  Invert keg, with gas dip tube at the lowest point.  Attach gas QD and blow out rest of sani using the residual pressure. 


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Title: Re: Oxidized DIPA -again...
Post by: klickitat jim on January 16, 2018, 01:59:01 AM
I can't do the sanitizer push. Just can't imagine leaving a pint of no rinse iodophor in my beer. Sorry, not happening. I prefer cardboard flavor over iodine
Unless you have trimmed dip tubes, it's probably more like half an ounce or thereabouts.
Trimmed
Title: Re: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 01:59:03 AM
Still wondering how much DO is introduced in the bit of sanitizer that remains in the keg.


Well it’s variable.  How much sanitizer? What temp water? How much DO in the water (8-12ppm). It would be easy enough to figure out.  Figure fermenting beer is sub 10ppb.  Say it’s an oz( .03 liter) and say the water is 10ppm( or 10000ppb) So then is straight math of 20l batch of 10ppb and .03 of 10000ppb.    What’s that like 15ppb on the sani and 10ppb on the main for 25ppb total?  Check that math I just quickly ran though it here on my phone. 


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Yeah, that's kind of what I was coming up with (on my phone too) but thanks for confirming, I  know you have a better grasp of this! My takeaway is: my biggest risk is in the purity of the CO2 itself, especially force carbing to 2.6v/v.  But that's one thing I can't do anything about, at least for now. Purging with sani and closed transfers I've got covered.  Wonder if some sort of inline CO2 "scrubber" exists.


That’s why you spund and just use bottle co2 to push.  Half the exposure. 


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Title: Re: Oxidized DIPA -again...
Post by: klickitat jim on January 16, 2018, 02:00:05 AM
Come on guys get out of your box!  Trim gas dip tube flush.  Push out everything you can.
Remove all connectors.  Invert keg, with gas dip tube at the lowest point.  Attach gas QD and blow out rest of sani using the residual pressure. 


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The gasses don't mix when the keg is inverted?
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 02:00:11 AM
Come on guys get out of your box!  Trim gas dip tube flush.  Push out everything you can.
Remove all connectors.  Invert keg, with gas dip tube at the lowest point.  Attach gas QD and blow out rest of sani using the residual pressure. 


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It seems so obvious now.  Thanks.
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 02:17:51 AM
Still wondering how much DO is introduced in the bit of sanitizer that remains in the keg.


Well it’s variable.  How much sanitizer? What temp water? How much DO in the water (8-12ppm). It would be easy enough to figure out.  Figure fermenting beer is sub 10ppb.  Say it’s an oz( .03 liter) and say the water is 10ppm( or 10000ppb) So then is straight math of 20l batch of 10ppb and .03 of 10000ppb.    What’s that like 15ppb on the sani and 10ppb on the main for 25ppb total?  Check that math I just quickly ran though it here on my phone. 


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Yeah, that's kind of what I was coming up with (on my phone too) but thanks for confirming, I  know you have a better grasp of this! My takeaway is: my biggest risk is in the purity of the CO2 itself, especially force carbing to 2.6v/v.  But that's one thing I can't do anything about, at least for now. Purging with sani and closed transfers I've got covered.  Wonder if some sort of inline CO2 "scrubber" exists.


That’s why you spund and just use bottle co2 to push.  Half the exposure. 


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Spunding may be somewhere in the future,  but not near. For now I do all I can to avoid gratuitous O2. Not to make your skin crawl, but did I mention I filter? I flush the filter with water I've lightly carbonated and degassed a few times, to try to reduce DO there. Good old Dalton again (I think.)
Title: Re: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 03:14:25 AM
Still wondering how much DO is introduced in the bit of sanitizer that remains in the keg.


Well it’s variable.  How much sanitizer? What temp water? How much DO in the water (8-12ppm). It would be easy enough to figure out.  Figure fermenting beer is sub 10ppb.  Say it’s an oz( .03 liter) and say the water is 10ppm( or 10000ppb) So then is straight math of 20l batch of 10ppb and .03 of 10000ppb.    What’s that like 15ppb on the sani and 10ppb on the main for 25ppb total?  Check that math I just quickly ran though it here on my phone. 


Sent from my iPhone using Tapatalk
Yeah, that's kind of what I was coming up with (on my phone too) but thanks for confirming, I  know you have a better grasp of this! My takeaway is: my biggest risk is in the purity of the CO2 itself, especially force carbing to 2.6v/v.  But that's one thing I can't do anything about, at least for now. Purging with sani and closed transfers I've got covered.  Wonder if some sort of inline CO2 "scrubber" exists.


That’s why you spund and just use bottle co2 to push.  Half the exposure. 


Sent from my iPhone using Tapatalk
Spunding may be somewhere in the future,  but not near. For now I do all I can to avoid gratuitous O2. Not to make your skin crawl, but did I mention I filter? I flush the filter with water I've lightly carbonated and degassed a few times, to try to reduce DO there. Good old Dalton again (I think.)

I have to ask why do you filter and what is your timeline for a lager from brewday until drink day?


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Title: Re: Oxidized DIPA -again...
Post by: hopfenundmalz on January 16, 2018, 03:21:08 AM
Gases don’t stratify, they mix.

Will someone please tell the AHA this ^^^


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I will repeat that I contacted the AHA, Dave Carpenter in this case, and an update is being worked on. 
Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 03:36:51 AM
Still wondering how much DO is introduced in the bit of sanitizer that remains in the keg.


Well it’s variable.  How much sanitizer? What temp water? How much DO in the water (8-12ppm). It would be easy enough to figure out.  Figure fermenting beer is sub 10ppb.  Say it’s an oz( .03 liter) and say the water is 10ppm( or 10000ppb) So then is straight math of 20l batch of 10ppb and .03 of 10000ppb.    What’s that like 15ppb on the sani and 10ppb on the main for 25ppb total?  Check that math I just quickly ran though it here on my phone. 


Sent from my iPhone using Tapatalk
Yeah, that's kind of what I was coming up with (on my phone too) but thanks for confirming, I  know you have a better grasp of this! My takeaway is: my biggest risk is in the purity of the CO2 itself, especially force carbing to 2.6v/v.  But that's one thing I can't do anything about, at least for now. Purging with sani and closed transfers I've got covered.  Wonder if some sort of inline CO2 "scrubber" exists.


That’s why you spund and just use bottle co2 to push.  Half the exposure. 


Sent from my iPhone using Tapatalk
Spunding may be somewhere in the future,  but not near. For now I do all I can to avoid gratuitous O2. Not to make your skin crawl, but did I mention I filter? I flush the filter with water I've lightly carbonated and degassed a few times, to try to reduce DO there. Good old Dalton again (I think.)

I have to ask why do you filter and what is your timeline for a lager from brewday until drink day?


Sent from my iPhone using Tapatalk
Ok, I know this isn't your way, but I'm happy with it.  I pitch 34/70 at 50°F, let fermentation go up to 54°F until 60% ADF (4 days) and let rise to 64°F until fermented out and yeast settling (7-8 days after pitching.)  Cool over 24 hours to the 30's, hold 24 hours more, and transfer off the yeast into lagering keg.  HARVEST YEAST AND REPITCH WITHIN 4 DAYS.  Beer is held at 29°-30°F for about 21 days (arbitrary -- 10 would likely do, this just fits my brew schedule.)  Then filter (coarse, 6-7 micron) and carbonate.  This system has me brewing every other weekend, doing equipment maintenance the other weekends.   It gives me clean, clear beer (filtration is sufficient to remove any yeast, chill haze will have settled in the lagering keg.)  And I have a good supply of yeast never more than 4 days from harvest to pitch.  I know this sounds more like conventional macrobrew method than what you advocate, that's true. But I've evolved this system carefully and every part really addresses a practical solution to some issue I've needed to address.  So, 5 weeks or so mash to tap, and good fresh beer with no real physical or flavor defects.
Title: Re: Oxidized DIPA -again...
Post by: hopfenundmalz on January 16, 2018, 04:12:48 AM
CO2 can pool if there is a source, and confined space. Where I worked there were sources (cars), and below floor level pits ( for the car hoists), that had to be tested with a sniffer before entry for service was allowed. Fun fact, just 10% CO2 in the air you are breathing will kill you.

With time the gases will diffuse. Mixing from convection currents helps too. That is why the CO2 in the atmosphere doesn’t pool at the surface due to gravity and kill us.

I remember when Lake Nyos burped, emitted a cloud of CO2 that ran down a valley and killed 1700+ before it dissipated.
https://en.m.wikipedia.org/wiki/Lake_Nyos

Running some CO2 into a keg might blanket the beer, for a little while. Then Dalton’s law says the CO2 and the O2 left will diffuse and reach equilibrium, exposing the beer to O2. Best practice says get the O2 out in the first place. Pushing sanitizer out is the way to go.
Title: Re: Oxidized DIPA -again...
Post by: The Beerery on January 16, 2018, 12:28:31 PM
Still wondering how much DO is introduced in the bit of sanitizer that remains in the keg.


Well it’s variable.  How much sanitizer? What temp water? How much DO in the water (8-12ppm). It would be easy enough to figure out.  Figure fermenting beer is sub 10ppb.  Say it’s an oz( .03 liter) and say the water is 10ppm( or 10000ppb) So then is straight math of 20l batch of 10ppb and .03 of 10000ppb.    What’s that like 15ppb on the sani and 10ppb on the main for 25ppb total?  Check that math I just quickly ran though it here on my phone. 


Sent from my iPhone using Tapatalk
Yeah, that's kind of what I was coming up with (on my phone too) but thanks for confirming, I  know you have a better grasp of this! My takeaway is: my biggest risk is in the purity of the CO2 itself, especially force carbing to 2.6v/v.  But that's one thing I can't do anything about, at least for now. Purging with sani and closed transfers I've got covered.  Wonder if some sort of inline CO2 "scrubber" exists.


That’s why you spund and just use bottle co2 to push.  Half the exposure. 


Sent from my iPhone using Tapatalk
Spunding may be somewhere in the future,  but not near. For now I do all I can to avoid gratuitous O2. Not to make your skin crawl, but did I mention I filter? I flush the filter with water I've lightly carbonated and degassed a few times, to try to reduce DO there. Good old Dalton again (I think.)

I have to ask why do you filter and what is your timeline for a lager from brewday until drink day?


Sent from my iPhone using Tapatalk
Ok, I know this isn't your way, but I'm happy with it.  I pitch 34/70 at 50°F, let fermentation go up to 54°F until 60% ADF (4 days) and let rise to 64°F until fermented out and yeast settling (7-8 days after pitching.)  Cool over 24 hours to the 30's, hold 24 hours more, and transfer off the yeast into lagering keg.  HARVEST YEAST AND REPITCH WITHIN 4 DAYS.  Beer is held at 29°-30°F for about 21 days (arbitrary -- 10 would likely do, this just fits my brew schedule.)  Then filter (coarse, 6-7 micron) and carbonate.  This system has me brewing every other weekend, doing equipment maintenance the other weekends.   It gives me clean, clear beer (filtration is sufficient to remove any yeast, chill haze will have settled in the lagering keg.)  And I have a good supply of yeast never more than 4 days from harvest to pitch.  I know this sounds more like conventional macrobrew method than what you advocate, that's true. But I've evolved this system carefully and every part really addresses a practical solution to some issue I've needed to address.  So, 5 weeks or so mash to tap, and good fresh beer with no real physical or flavor defects.


I have nothing against macro brewing tactics or filtering.  I have a lot against dissolved o2!

Conversely without filtering/fining I can get really clear beer after 3 weeks and brilliantly clear after 4.  Using process alone. 

(https://uploads.tapatalk-cdn.com/20180116/e08101b5e540f3e6bc021a6eda03d141.jpg)


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Title: Re: Oxidized DIPA -again...
Post by: Robert on January 16, 2018, 01:18:54 PM


I have nothing against macro brewing tactics or filtering.  I have a lot against dissolved o2!

Conversely without filtering/fining I can get really clear beer after 3 weeks and brilliantly clear after 4.  Using process alone. 

(https://uploads.tapatalk-cdn.com/20180116/e08101b5e540f3e6bc021a6eda03d141.jpg)


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Like I said, I do all I can to avoid gratuitous O2.  That's why I'm in this thread advocating for purging with sani and closed transfers, and do what I can to minimize pickup at filtering.  I also feel that it's best to address flavor maturation (best achieved at 64°F,) physical stabilization and carbonation discretely.  A compromise process to achieve all 3 may not be ideal for any them.  (Philosophically, this is akin to step mashing, optimizing each part of the process; OTOH brewing is full of compromises.) Clearly you and I have each given long and careful consideration to identifying each goal at every stage in brewing and the preferred means to achieve them.  And come up with different answers.  I think that's a beautiful thing about brewing especially as a hobby.   My process is a result of evolution and learning and will no doubt continue to be so. At this point I dont identify any issues warranting a radical change.  Nice looking beer, by the way!
Title: Re: Oxidized DIPA -again...
Post by: BrewBama on January 16, 2018, 07:46:42 PM
Gases don’t stratify, they mix.

Will someone please tell the AHA this ^^^


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I will repeat that I contacted the AHA, Dave Carpenter in this case, and an update is being worked on.

My deepest and most sincere apology. I recall you posting the AHA staff has been contacted and they will decide the appropriate action but do not recall an update is being worked on. I will no longer speak of the issue again lest I be duly chastised for causing you to repeat yourself.


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Title: Re: Oxidized DIPA -again...
Post by: hopfenundmalz on January 16, 2018, 08:18:37 PM
Gases don’t stratify, they mix.

Will someone please tell the AHA this ^^^


Sent from my iPhone using Tapatalk
I will repeat that I contacted the AHA, Dave Carpenter in this case, and an update is being worked on.

My deepest and most sincere apology. I recall you posting the AHA staff has been contacted and they will decide the appropriate action but do not recall an update is being worked on. I will no longer speak of the issue again lest I be duly chastised for causing you to repeat yourself.


Sent from my iPad using Tapatalk
After the contact, Dave worked on an update and i was asked for input. That last part you didn’t know, sorry about that. Hopefully the correct way will be printed soon. I will ask Dave for an update.
Title: Re: Oxidized DIPA -again...
Post by: majorvices on January 17, 2018, 12:22:11 AM
CO2 can pool if there is a source, and confined space. Where I worked there were sources (cars), and below floor level pits ( for the car hoists), that had to be tested with a sniffer before entry for service was allowed. Fun fact, just 10% CO2 in the air you are breathing will kill you.

With time the gases will diffuse. Mixing from convection currents helps too. That is why the CO2 in the atmosphere doesn’t pool at the surface due to gravity and kill us.

I remember when Lake Nyos burped, emitted a cloud of CO2 that ran down a valley and killed 1700+ before it dissipated.
https://en.m.wikipedia.org/wiki/Lake_Nyos

Running some CO2 into a keg might blanket the beer, for a little while. Then Dalton’s law says the CO2 and the O2 left will diffuse and reach equilibrium, exposing the beer to O2. Best practice says get the O2 out in the first place. Pushing sanitizer out is the way to go.

We have problems in the brewery with Co2 pooling in the office. We have Co2 readers in place in serval places and it definitely pools in certain areas.

OP: If it was mentioned I missed it: Do you think the o2 happened during dry hopping? I never go directly in a tank when I dry hop any loner. I add hops to the an empty tank, purge that tank with Co2, then run my beer into that tank through those hops.
Title: Re: Oxidized DIPA -again...
Post by: hopfenundmalz on January 18, 2018, 05:44:03 PM
Update.

Dave Carpenter got back to me. They are working on the write up, and he asks that we all have patience before it is published.

Title: Re: Oxidized DIPA -again...
Post by: Robert on February 07, 2018, 12:35:18 AM
Come on guys get out of your box!  Trim gas dip tube flush.  Push out everything you can.
Remove all connectors.  Invert keg, with gas dip tube at the lowest point.  Attach gas QD and blow out rest of sani using the residual pressure. 


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Okay I finally did this.  Simply brilliant.  Will never purge another way again, have to trim ALL my gas tubes now.

(Actually found replacement gas tubes impossible to trim: made of lightweight aluminum, easy to crush, also can't get a hold of anything to secure it while using tubing cutter.  Had a couple spare steel liquid tubes, trimmed off the flanged end to correct length.  So need more spears.)

Anyway, belated thanks for the tip!
Title: Re: Oxidized DIPA -again...
Post by: Aksarben on February 07, 2018, 06:52:34 PM
After talking with our graduate Associate Winemaker, (degree in food science) and what I have been taught from the owner, also a graduate with specializing in chemistry, I will post the following:

Gases mix = True
Gases stratify = True.

Both are true if you understand that Carbon Dioxide is a dense molecule and settles to the very bottom in a mixed gas enclosure.   We gas the tanks at the winery, and have done so since I've worked there.  This is from the boss who owns the winery and has the degree.  CO2 is heavier than air.  It does stratify, but stratifies to be the very bottom of whatever gas (air) it's around.   Nitrogen is a gas, but nearly the same molecular density as normal air, so it mixes very well and does not, for practical purposes, stratify  or separate out.

CO2 does settle to the bottom and lays in the bottom and as wine is pushed into the tank from the bottom valve moves up the tank until is is purged out the top of the tank through the open lid.

This is what I do, and will continue to do so, and no cutting pipes.... I open the main lid and use pure CO2 and put the tube into the very bottom of the keg, THROUGH THE TOP LID, and then slowly add a good measure of CO2.  While it is filling there is mixing, but when the gas stops coming in, the stratification begins.
You can pour out CO2 just like water.  I have witnessed this first hand when I've opened the door on a large tank I'm centrifuging from, after the wine level is below the door, and see, yes see, the CO2 pouring out.  It does not have a color but you can see the shimmer of light being bent - distorted by the out-flowing CO2 from the tank.

Once I, (or you) have put CO2 into a keg through the top lid opening, allow just a few seconds and use a barbecue lighter and light it an put in the keg.  If the flame goes out within 2 inches of inserting into the keg, you have sufficient CO2, not wasted and now you can put on your lid.  When ready to fill, generally within a few minutes, you can either take off the lid and put the hose into the bottom of the keg and fill from the bottom up as the CO2 "pours" out the top of the opening, or hook up to the "OUT" side and fill from the bottom  - up - by having the pressure release valve in the "HOLD OPEN" position.   I prefer the filling through the top of the lid as I can see and stop the flow when the beer is near the top.  Immediately upon filling and taking out the hose (if that is what you used) put the lid on and while the release valve is still opened add CO2 for about 5 seconds and ALL of the last of any air will not be purged out and replaced by CO2.

Wine making and beer making is not rocket science. Keep it simple.  RDWHAHB

Do this experiment... take a nice clean keg 2.5, 3, 5, size doesn't matter, and put in CO2 for about 30 seconds as I have said above.  let it settle and light a candle.  Now take that keg and put out the candle by "pouring" out the CO2 form the keg over the candle. Candle will go out, guaranteed.
Title: Re: Oxidized DIPA -again...
Post by: hopfenundmalz on February 07, 2018, 07:09:20 PM
A candle will go out if the air has a 10% CO2 concentration.
Title: Re: Oxidized DIPA -again...
Post by: Aksarben on February 07, 2018, 07:24:39 PM
A candle will go out if the air has a 10% CO2 concentration.
Point was, it (CO2) flows out like water. :)  I'll remember than in June when I turn 65.   ;)
Title: Re: Oxidized DIPA -again...
Post by: Robert on February 07, 2018, 07:33:30 PM
Is scale an issue here?  Gases will mix first at the interface, I'm thinking. In an industrial setting, or near a burping lake, it can take long enough for the whole depth to fully mix that you have time to die. (Candle, schmandle, you'll go out way below 10%!) But in a keg or a bottle, for all practical purposes, it's all interface: the area mixing immediately is a sufficiently significant portion of the whole to pose a problem for us?
Title: Re: Oxidized DIPA -again...
Post by: klickitat jim on February 07, 2018, 08:47:23 PM
Evrryone can purge their kegs any way they want and the quality of their beer will be exactly what they perceive it to be.
Title: Re: Oxidized DIPA -again...
Post by: Aksarben on February 07, 2018, 09:27:07 PM
Everyone can purge their kegs any way they want and the quality of their beer will be exactly what they perceive it to be.

Ain't it great!  - Jack Daughery
Title: Re: Oxidized DIPA -again...
Post by: bayareabrewer on February 09, 2018, 04:38:07 PM
Winemaking isn't infinitely more forgiving in terms of oxidation than beer. We also have as close to a magic bullet there is in meta. I've done a lot of both, and a lot of winemaking best practices would make the average brewer cringe.
Title: Re: Oxidized DIPA -again...
Post by: Aksarben on February 12, 2018, 02:39:54 PM
Curios if anyone has tried BrewTan B?   Wondering how closely it is related to Galacool SP  which is a specific tannin from Oak tree galls?  Tannins are used in winemaking to stabilize color and the wine.
Title: Re: Oxidized DIPA -again...
Post by: Robert on February 12, 2018, 02:48:13 PM
Curios if anyone has tried BrewTan B?   Wondering how closely it is related to Galacool SP  which is a specific tannin from Oak tree galls?  Tannins are used in winemaking to stabilize color and the wine.
Vernon, search "BrewTan" here on the forum.  There's been enough talk about it that I just used it for the first time this weekend.  Seems widely used in pale beers.
Title: Re: Oxidized DIPA -again...
Post by: Aksarben on February 12, 2018, 04:19:27 PM
Looking in our Laffort catalog is Tanin Galalcool
1) Inhibits of natural oxidation enzymes (laccase,  polyphenol oxidase), more efficiently than SO2. 2)  Precipitaion of some of the unstable proteins, as efficiently as bentoniet but without aroma loss.
3) Facilitates clarification   
50-200 ppm.   
A highly purified extract of the chestnut gall tannins..... sounds a lot like BrewTan B to me.

Most tannins are quite effective at reducing oxidation.  Makes me wonder if additions of rice hulls that can leach tannins into the wort is a special benefit.  As I understand though, most of the tannin extraction comes from higher than normal pH in the must.

ref:  https://www.laffort.com/en/products/tannins/224
Title: Re: Oxidized DIPA -again...
Post by: Big Monk on February 12, 2018, 04:26:53 PM
Looking in our Laffort catalog is Tanin Galalcool
1) Inhibits of natural oxidation enzymes (laccase,  polyphenol oxidase), more efficiently than SO2. 2)  Precipitaion of some of the unstable proteins, as efficiently as bentoniet but without aroma loss.
3) Facilitates clarification   
50-200 ppm.   
A highly purified extract of the chestnut gall tannins..... sounds a lot like BrewTan B to me.

Most tannins are quite effective at reducing oxidation.  Makes me wonder if additions of rice hulls that can leach tannins into the wort is a special benefit.  As I understand though, most of the tannin extraction comes from higher than normal pH in the must.

ref:  https://www.laffort.com/en/products/tannins/224

Just to be clear, tannins don't reduce oxidation in an active sense (i.e. remove oxygen), they simply remove the potential for oxidative and other staling precursors down the line.
Title: Re: Oxidized DIPA -again...
Post by: denny on February 12, 2018, 04:49:52 PM
Curios if anyone has tried BrewTan B?   Wondering how closely it is related to Galacool SP  which is a specific tannin from Oak tree galls?  Tannins are used in winemaking to stabilize color and the wine.

I've used it in every batch for the last couple years.  Biut since I've never used Galacool, I have no idea how it compares.