Spunding Valve Oxygen NEIPA Question

Discussion in 'Homebrewing' started by drink1121, Apr 16, 2018.

  1. drink1121

    drink1121 Initiate (0) Mar 23, 2009 California

    generic topic sorry. I want to transfer an IPA from primary to a keg with spunding valve. the goal is to eliminate some oxygen that might be picked up during transfer. the beer should be nearly attenuated at time of transfer, without cold crashing. I am thinking of adding 1-3 ounces of sugar to the keg in order to give the yeast something to eat, in order to scrub out some oxygen and start the carbonation process and let it sit for a few days with the spunding valve. has anyone done this? results? if not, good idea or am I just wasting a step?
  2. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    If you time it right, i.e. leave the right amount of not-yet-fermented sugars in the beer when you transfer, there's no need to add any sugar, and you can fully carbonate the beer.
    chavinparty likes this.
  3. wasatchback

    wasatchback Aspirant (283) Jan 12, 2014 Utah

    Yeah no sugar and .04 - .02 left you’re good to go. If you add sugar you’ll create more Co2 (and aroma) that will get blown off if you set your Valve to the correct setting.

    What’s your method for purging the keg?
    drink1121 likes this.
  4. drink1121

    drink1121 Initiate (0) Mar 23, 2009 California

    right, but what if I didnt time it correctly, you know? this measure would be in case I didnt!
  5. drink1121

    drink1121 Initiate (0) Mar 23, 2009 California

    I pump in C02 when keg is closed and then release it all. I do this 3-4 times at 20 psi.
  6. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    Well, if you know your recipe/process, i.e. you know pretty closely what your FG will be, it should be pretty easy. But if in doubt, I'd say err on the side of transferring when there is more than the sugar you'll need for carbonation rather than less. The spunding valve (properly set) will ensure you don't overcarbonate.
    drink1121 likes this.
  7. PortLargo

    PortLargo Devotee (436) Oct 19, 2012 Florida

    This is what a lot of keggers do and it will certainly work. But if going for the extreme, I suggest after keg is sanitized to fill it with water, then pump it out with CO2. With the purge method you never really get all the air out and will use 3 keg's worth of gas (at 20 psi). Pumping out the water will void the keg-space more efficiently and uses less gas (1 keg's worth ~ 2 psi).

    How are you transferring from primary to keg?
  8. drink1121

    drink1121 Initiate (0) Mar 23, 2009 California

    wouldnt the tap water contaminate the keg? I have a spigot that I use with a hosed attached to it, to transfer from primary to keg using gravity.
  9. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    I've thought about doing this before. But I wonder how much water is left in the keg (on the bottom) for an average keg, because there will be some dissolved O2 in that water. I suppose someone could do the math and figure out how much DO that would mean for the beer once it's mixed with the residual water. When purging with CO2, you can get some very low O2 levels, if you're willing to use a lot of CO2. But the O2 in the residual water left by the alternate method would be more or less a constant.
  10. PortLargo

    PortLargo Devotee (436) Oct 19, 2012 Florida

    Not in my experience . . . remember this is now beer which is generally antiseptic because of the alcohol and a ph of 4'ish.

    Either way you go I'll suggest you put a swivel nut on your hose and attach to a liquid quick disconnect. Then fill the keg with lid sealed (PRV open) from the bottom up. It still won't hurt to give Señor Keg a few burps when you finish (for old time sakes) . . . but now you're only purging a tiny headspace.

    I've never wondered this but it is a fair concern. I have long dip tubes and after purging (or normal keg-kick) there is only about 1 tablespoon of water/beer remaining. That's not zero but it ain't much. I invert the keg with the PRV open and there is not enough liquid to run out of the open valve.

    I suppose if you wanted to go ultra-extreme you could boil the water first, then transfer hot into keg. That'd kill the nasties and if a molecule of oxygen remains it would be tough enough to have my respect.
  11. wasatchback

    wasatchback Aspirant (283) Jan 12, 2014 Utah

    Fill the keg with Star San or Idophor treated water to the very top. Push a pint or two out. Then purge the headspace 8-11 times (I can’t remember the exact number right now) with 30 PSI then push the rest of the water out.

    If you cut your dip tube flush you can then tip the keg upside down and tilt it towards the gas side, leave it there for a bit then hookup a gas post and if there’s any water left it’ll flow out. I believe some will come out the PRV if you pull it while upside down as well.

    Purging your keg 3 times at 20 PSI leaves a ton of O2 in there.

    I also leave 10-20 PSI in the keg, when I hookup the transfer line to the keg it pushes out any possible O2 in the line, hook it up to whatever vessel you’re transferring from when there’s still some CO2 flowing.

    The tiniest amount of O2 makes a huge difference in preserved Hop aroma. It’s what goes first.

    You can have incredibly hoppy beer last for months if you’re crazy diligent about O2 pickup.

    Yes yeast will scavenge some remaining O2 if they’re active but how much? I don’t know that equation, maybe someone smarter than me does.
    Rrrainy likes this.
  12. wasatchback

    wasatchback Aspirant (283) Jan 12, 2014 Utah

    Pretty sure you can find the amount of O2 left in remaing water on the lowdo site, I’ve seen it posted somewhere..
  13. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    We don't need no stinkin' PRVs! (@drink1121 has a spunding valve.)
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  14. drink1121

    drink1121 Initiate (0) Mar 23, 2009 California

    I didnt realize I could still fill this way if I wasnt using pressure to transfer. had no idea it would still work with gravity. thanks!
  15. PortLargo

    PortLargo Devotee (436) Oct 19, 2012 Florida

    It's a mite slower because gravity has to "push" up the beer as it fill the keg. Just place your primary on counter-top and keg on the floor and it'll work, takes me about 12 minutes for 5 gallons.

    I'm comfortable pumping water through the keg, at this level the risk of contamination is nil. I wouldn't put 5 gals of boiling water in a keg at gun-point (pretty sure you picked up on that humor). However, an ounce of starsan will treat 5 gallons of water so it wouldn't be terribly expensive to push all 5 gallons of water treated with starsan.

    This also makes a lot of sense and I've been skipping this step (will incorporate). Easy and effective.

    About spunding valves: I hear stories they are unreliable . . . anyone have real world experience? Make and Model? Also, much more complex, but you're approaching the area where you have to be concerned with the quality of CO2 you'll be pushing this magnificent IPA. Anyone have a supplier that publishes carbon dioxide purity (and you trust)?
  16. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    My first valve was from one of the online HBSs. I don't remember the model, but it's the one where the body looks like brass. It sucked. Now I build my own and they don't suck.
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  17. drink1121

    drink1121 Initiate (0) Mar 23, 2009 California

    I built my own, which was incredibly easy. if it wasnt easy, I wouldnt have done it. I have only used it once but it worked great and my IPA carbonation only took a few days after cold crashing. got those tiny little bubbles on it as well.
  18. minderbender

    minderbender Initiate (196) Jan 18, 2009 New York

    [Edited to add: the TLDR here is that oxygen is not very soluble in water and so I think pushing sanitizer out of the keg with CO2 is likely to be the best approach.]

    So I did some back-of-the-envelope calculations on this, and it seems to me that the amount of oxygen dissolved in the residual sanitizer would be small relative to the amount of oxygen likely to remain after purging with CO2 in the traditional way.

    To start with, if the internet is to be trusted, under normal conditions room temperature water will have about 10 milligrams per liter of dissolved oxygen. Assuming your keg has half a liter of sanitizer left after pushing the sanitizer out with CO2, that's about 5 milligrams of oxygen.

    Compare that to the amount of oxygen in air. Again, if the internet is to be believed (and if I've done my math right), under normal conditions there are about 5 grams of oxygen in 5 gallons of air. You could cut that in half 8 times and still have far more oxygen than would typically be dissolved in half a liter of sanitizer.

    I'll make one more observation, which is that the amount of oxygen that dissolves in water is a function of the partial pressure of oxygen in the gas above the water. So let's say you fill your keg with sanitizer and then push it out with CO2. The partial pressure of oxygen in the keg would be very low, and so a lot of the oxygen in the sanitizer would come out of solution. I don't know how quickly that would happen, but when you rack the beer into the keg, a fair amount of the oxygen that was in the sanitizer should be leaving the keg as the gas inside is displaced by beer.

    So my strong hunch is that if you're trying to minimize the amount of oxygen in the keg, the sanitizer method is the way to go. Please let me know if I've gotten something wrong. (Would also be curious to hear @TheBeerery's thoughts.)
    VikeMan likes this.
  19. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    Some data to add to the analysis:
    minderbender likes this.
  20. Naugled

    Naugled Defender (612) Sep 25, 2007 New York

    Does that chart assume you're starting with a keg full of air or one filled with CO2 (using the fill with starsan method)?
  21. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    That chart assume (I think) air, at atmospheric pressure.
  22. TheBeerery

    TheBeerery Initiate (85) May 2, 2016 Minnesota

  23. MorningDew72

    MorningDew72 Initiate (44) Aug 15, 2014 Washington

    How's everybody that ferments in carboys getting the transfer started? I've performed closed transfers out of glass carboys using CO2 but that scares the crap out of me and I don't do it anymore for fear of shattering the carboy if something goes wrong. I'm sure the cap would pop off before it shattered but you never know when dealing with pressure and a glass vessel that isn't designed for high pressure. It seems like gravity never was able to keep the liquid flowing without constant pressure in the headspace of the carboy for me.

    One of those sanitary filters seems like it would work fine getting it started but the idea of blowing oxygen/CO2/whatever else we exhale has me wondering why anyone would go that route vs. using an auto syphon with the hose connected to the liquid ball lock.
  24. hoptualBrew

    hoptualBrew Zealot (587) May 29, 2011 Florida

    This is roughly what I do.

    Push out star san with CO2, then purge keg x2 (this time through dip tube) and vent through pressure relief valve at 20 psi, then x1 slow same way at 1-2 psi with pressure relief valve open for a few mins, fill with 10 psi, tip keg upside down & wait a few mins then empty remaining Star san through gas in post.
  25. hopfenunmaltz

    hopfenunmaltz Meyvn (1,391) Jun 8, 2005 Michigan

    You only have to use 1 PSI to get the liquid high enough to start the siphon. 1 PSI will force the liquid 27.7 inches upwards, more than enough to do it.
  26. billandsuz

    billandsuz Disciple (372) Sep 1, 2004 New York

    I would not put a lot of faith in those numbers. As I understand it, the sampling method was questionable at best. Traditional O2 meters are famously temperamental to calibrate and maintain. The values reported real funky too. Confidence level is just about zero.

    If we are to believe 20 purges at 25 psi are required to obtain 0.00 ppm saturation, well, maybe. But based on what we do not know.

    Just saying.
  27. minderbender

    minderbender Initiate (196) Jan 18, 2009 New York

    I don't think this chart represents empirical results, it is an analytical result under certain assumptions. Basically the concept is that if you hook up your CO2 tank, pressurize the keg, turn off the CO2, and then vent, and then repeat, you will eliminate a certain percentage of the oxygen in the keg each cycle. I don't keg and I can't comment on the realism of the assumptions, but I think the chart is just a mathematical extrapolation from the assumptions.

    Now I'm curious how people purge their kegs and whether they think the assumptions are realistic.
  28. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    IIRC, they are not based on measurement. They're based on computations. There was a similar discussion in another thread. The only thing that must be "believed" is that when you pressurize a keg, turbulence from pressurizing equally mixes the old and new gasses.

    Here's the thread:
  29. billandsuz

    billandsuz Disciple (372) Sep 1, 2004 New York

    I thought there were a few actual measurements?, questionably collected. Starting with 21% atmosphere we end up with all those numbers?

    What I'm saying is that this chart is basically useless as a scientific analysis of keg purging.
    A lot has been made of the utility of keg purging. If this is the foundation of the discussion, we should reconsider.
  30. billandsuz

    billandsuz Disciple (372) Sep 1, 2004 New York

    That was a fun one!
    Not trying to sidetrack this conversation but it is an important consideration.

    The part where you can get to 0.00 ppm DO with 20 purges at 25 psi... and goes on to claim bottle CO2 is 500 ppb oxygen... so if we are provided that value how does that figure into the chart? We just ignore that part?

    So, it's ND or it's not ND. ?????
    An entire business model falls apart when you question some basic assumptions. I'm one guy who is thoroughly not impressed. Packaged real well, but the evidence is based on some questionable work.
  31. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    I don't think the chart was made by @TheBeerery, and AFAIK it does ignore whatever trace O2 is in bottled CO2. BTW, I don't believe he ever claimed 500 ppb. I believe it was 150. When you think about how small 150 ppb is, you will realize that including it in the chart would not change a thing; it's less than rounding error when measure ppm.

    To me, the important takeaway from the chart isn't really "X purges at Y pressure will get you to 0 ppm" (though I really don't doubt the math or the purge/dilution equation behind it). It's that the 4 or 5 purge cycles that a lot of people do doesn't really get you very close. Everyone can decide for themselves if ~1000 ppm is good enough for their beers.
    billandsuz likes this.
  32. Brewday

    Brewday Initiate (121) Dec 25, 2015 New York

  33. billandsuz

    billandsuz Disciple (372) Sep 1, 2004 New York

    Nice summary, and you are correct the claimed ppb in bottle CO2 is 150 ppb, though that is probably also dubious. But 150 is not 500 none the less.

    Maybe the 4 or 5 purges really does get headspace O2 down to an acceptable and practicle amount. We can discuss "acceptable and practical amount", there is plenty of data for that around. But the chart is useless and it should be ignored. Which is why I say don't put too much faith in those numbers. As an aside, I think it is appalling that an entire cottage business is predicated on a foundation of bullshit. Full stop.

  34. VikeMan

    VikeMan Meyvn (1,476) Jul 12, 2009 Pennsylvania

    Why do you say that?
    TheBeerery likes this.
  35. thebriansmaude

    thebriansmaude Initiate (69) Dec 16, 2016 Alberta (Canada)

    For those of you that regularly use a spunding valve, what do you do to manage dry hops? If you were to dry hop at high krausen for example, there would still be some hop debris flying around when you transfer with a few gravity points left - do you just rack over to the serving keg w/ hop bits included or do you use bags ?

    I normally go bagless for max extraction but am stumped on how to do this on a NEIPA without using hop bags.
  36. TheBeerery

    TheBeerery Initiate (85) May 2, 2016 Minnesota

    Floating Diptube.
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  37. MorningDew72

    MorningDew72 Initiate (44) Aug 15, 2014 Washington

    Yeah, the only issue I have is similar to what @thebriansmaude is talking about. I've had an issue where dry hops clogged the ball lock on a closed transfer and I had to stop it and whip out the auto syphon.

    I think I might just start dry hopping in the carboy during active fermentation with muslin bags so I can go back to closed transfers and not have to worry about a clog, followed by a dry hop in the keg with floss tied to the lid so I can remove it after the fermentation is done, prior to chilling. It's such a pain in the ass getting bagged hops in and out of a carboy though. I did a dry hop process like this on my most recent IPA and I was satisfied, no closed transfer though.
  38. minderbender

    minderbender Initiate (196) Jan 18, 2009 New York

    I know these discussions have gotten heated in the past, and I don't want that to happen again, but I do think the chart is basically valid. You can quibble with the number of significant digits, but that's not really the point. The point is that even after numerous purging cycles, the amount of oxygen remaining in the keg can be significant. And the chart is a straightforward application of math based on reasonable assumptions.

    I've done some back-of-the-envelope calculations, and as far as I can tell at 20°C (68°F), there are about 0.042 moles of gas in a liter of atmosphere. So you can take the liters of head space in your keg, multiply it by 0.042, multiply it by the parts per million from the chart, and divide by a million, and you'll have moles of O2 in the headspace.

    Then each mole of O2 that dissolves into 5 gallons of beer represents an increase of about 1,670,000 ppb. (A mole of O2 should weigh about 32 grams, which is divided into 19 liters of beer weighing about 1,010 grams per liter.)

    So to give a few examples, if you have a liter of headspace and you've purged 5 times at 30 psi, the remaining oxygen would be enough to increase the dissolved oxygen in the beer by about 57 ppb. (I am making the simplifying assumption that all of the oxygen in the headspace will eventually dissolve into the beer.) If you look at the original post, you will see that this represents a large fraction of the total O2 that might be found in packaged beer produced by a professional brewery. (Bear in mind I'm assuming a liter of headspace. I don't know how realistic that is, but adjust the numbers according to your own situation.)

    By contrast, if you purge 4 times at 30 psi, then the remaining oxygen would be enough to increase the dissolved oxygen in the beer by about 172 ppb. That is more than the total O2 you would find in packaged beer from a professional brewery, and that's just the oxygen from the keg's headspace after the keg has been purged 4 times with CO2! With three purge cycles at 30 psi, you're picking up about 523 ppb.

    (Everyone should feel free to double-check my math, I could easily have gotten something wrong.)

    So that's why I think the chart is helpful—it gives you a sense of how many purge cycles you have to complete to get to reasonable levels of O2. Of course, your definition of "reasonable levels of O2" is subjective, and you could easily conclude that picking up 57 ppb or 172 ppb or whatever is an acceptable result. On the other hand, you could also decide that you prefer the 15 ppb that @TheBeerery calculates would be contributed if you use the sanitizer method. Or of course you could go whole hog and use his recommended "fermentation purge" method, in which you fill the keg with CO2 produced during fermentation. But you can't make these decisions on an educated basis unless you have a chart like the one under discussion, and so I think it is useful.
    VikeMan likes this.
  39. billandsuz

    billandsuz Disciple (372) Sep 1, 2004 New York

    That chart says air is 210,000 ppm oxygen. That is to say 21%. Well, actually it states that air is 210,000.00 ppm. But air is not 21% oxygen, it is 20.95% oxygen. That does of course matter if you are presenting the foundation of your data on a known fact. It's PF sloppy. It is not nit picking to note this ridiculously lazy reporting.

    So then the numbers go on to extrapolate data based on false information. And that is sloppy.

    Hey, what's 0.05% anyway? That's 500 ppm in fact. Now, is 500 ppm oxygen relevant? Based on the authoritative data presented it would seem to be. Doesn't really matter. The whole chart is wack just based on that.

    And it is a model, not fact.

    GIGO. As I said the foundation is bullshit. Grab samples from the headspace and have them analyzed at a lab if you must, then take it from there.

    We don't, as a rule, want to work out ways to make the data real and relevant. That is my opinion.
  40. minderbender

    minderbender Initiate (196) Jan 18, 2009 New York

    But it's not comparable to, say, a macroeconomic or meteorological model that of necessity involves a tremendous amount of simplification and measurement error. With those models, it's reasonable to apply a fair amount of skepticism (although actually meteorological models are pretty impressive these days). The chart, by contrast, is just a straightforward mathematical exercise. It's a model in the same way that multiplying the last 2-3 digits of your specific gravity by your volume gives you a measure of the amount of sugar in your wort, which you can then divide by expected final volume to figure out what your SG will be after the boil. That's a "model" but it's also pretty much a fact, and no one would question its accuracy or usefulness. The chart is based on a comparable level of extrapolation from observable facts, though the math might be a bit harder.

    At worst the table is misleading in its level of precision. Fair enough, I agree that it's silly to specify numbers to the hundredths when you've started with a round number. But as I said, that's just a quibble. The chart is not really "off by 500 ppm," but rather off by about a quarter of a percent, which is equal to 500 ppm only at the first, no-purge stage. If I used the chart to calculate that I would get 57 ppb of oxygen in my beer, and the real answer turned out to be 56.8 ppb, it wouldn't change anything.

    In short I don't think your skepticism is justified here. People can decide for themselves whether oxygen exposure is a big deal for their beers, and this chart may be irrelevant to some people, but the chart is fundamentally sound and it shouldn't be dismissed merely because of a questionable choice on significant digits.
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