aging mead in a keg

I'm considering springing for 2 brand new,10 gallon corny kegs for aging my meads. If I understand this process correctly, aging under pressure seems like an easy way to avoid having to worry about topping up, or having a bladder deflate on a floating lid, not to mention a convenient way to rack/bottle when the time comes. For those of you already doing this, is it as good as it looks at first glance? Having done some research, I am a little concerned about availability of parts and getting gas refills.

I have never used kegs before, so I'm also wondering how I might manage the headspace during the aging process for different meads. Since most do not benefit from o2 exposure after fermentation, it seems pretty straightforward; purge o2 from headspace after filling, pressurize, and leave it alone. But a heavier bodied melomel, that has considerable tannins to polymerize, might benefit from periodic headspace flushing. Is this a pretty straightforward process? Do you prefer argon or nitrogen over co2? Are they all equally accessible? Can co2 be used without imparting effervescence?

Thanks -

zipmont said:

I'm considering springing for 2 brand new,10 gallon corny kegs for aging my meads. If I understand this process correctly, aging under pressure seems like an easy way to avoid having to worry about topping up, or having a bladder deflate on a floating lid, not to mention a convenient way to rack/bottle when the time comes. For those of you already doing this, is it as good as it looks at first glance? Having done some research, I am a little concerned about availability of parts and getting gas refills.

I have never used kegs before, so I'm also wondering how I might manage the headspace during the aging process for different meads. Since most do not benefit from o2 exposure after fermentation, it seems pretty straightforward; purge o2 from headspace after filling, pressurize, and leave it alone. But a heavier bodied melomel, that has considerable tannins to polymerize, might benefit from periodic headspace flushing. Is this a pretty straightforward process? Do you prefer argon or nitrogen over co2? Are they all equally accessible? Can co2 be used without imparting effervescence?

Thanks -

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That's one way of handling the airspace etc once a batch has been made/racked/cleared etc. There are cheaper methods, but what the hell, if you have the money for the kegs then why not.

You don't have to apply enough pressure to carbonate, unless that's what you're aiming for (then you'd have to serve it from the keg most likely as it'd mean champagne/sparkling wine bottles, appropriate stoppers, wire cages, etc etc).

If you're gonna just use enough CO2 to prevent oxidation, then it should work fine. You can just move to a carboy and use a Mityvac, or enolmatic or other small vacuum pump to de-gas before bottling......

fatbloke said:

You don't have to apply enough pressure to carbonate, unless that's what you're aiming for ...

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Do you know of any advantages to using co2 as opposed to argon or nitrogen? Cost? Availability? Other?

fatbloke said:

If you're gonna just use enough CO2 to prevent oxidation, then it should work fine. You can just move to a carboy and use a Mityvac, or enolmatic or other small vacuum pump to de-gas before bottling......

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I wonder if there's a way to create a vacuum in a keg? Doesn't seem like they would implode. Or perhaps using the wand/drill method to degas in the keg? Then bottling could be done straight from the keg, using the homemade bottle filler method -

I must say, the enomatic is looking pretty good though.

Thanks -

You might be over thinking this a bit. Kegging is pretty easy stuff. I am mostly a beer brewer, use kegs almost exclusively, and have recently brewed a few meads using kegs. Could not be much easier. Natural CO2 production will fill the head space with CO2, no real need to pressurize, just rig an airlock and you're good to go. I have mead bubbling away in two 5 gallon corny kegs right now.

Transfers to bottles are quite easy. You can buy one of the fancy "beer guns" or just a bit of tubing and a drilled stopper works fine too (lots of threads on how to do this here).

Your posted location, Clifton, WA, is near Seattle, getting keg parts and CO2 refills should be quite convenient. Only thing to consider I think is that the 10 gallon cornys are much less common.

Curtis2010 said:

Natural CO2 production will fill the head space with CO2, no real need to pressurize, just rig an airlock and you're good to go.

Transfers to bottles are quite easy. You can buy one of the fancy "beer guns" or just a bit of tubing and a drilled stopper works fine too (lots of threads on how to do this here).

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I'm already set up with lots of 20 gallon primaries and 11 gallon secondaries, and am only interested in kegs for tertiary, bulk aging, and perhaps bottling from.

The issue that fatbloke brought to my attention was degassing, which I had overlooked. I really need to degas my still meads prior to bottling, but the idea of transferring 50 gallons of mead from kegs back into (glass) carboys to vacuum degas is too labor intensive. It's also expensive since I don't have glass carboys. So it seems if I'm going to use kegs for tertiary aging, I have to find another way to degas, like the drill/degassing wand method, though I'm not sure how well this works in a keg. It seems doable in a 10 gallon keg.

Ok, so as far as which gas, parts and kit are concerned, I don't use them at the moment (on "to do" list). Plus I'm in the UK, so prices, availability, etc are very different.

I suggested glass, as its easier generally, to make the connections and you don't need much vacuum to rack and de-gas. Plus you can see what's going on, which is very helpful.

I don't know about the availability of larger glassware your side of the pond. I have a couple of the nice Italian 54ltr carboys, but how easy they might be to get (or similar), it don't know.

Just that I've got the 2/twin holed adaptor for vacuum racking and its easy to blank one hole for de-gassing.

I usually de-gas because I find not doing that leaves a slight, bland acidity, found in champagne/sparkling whites. Which is fine if that's what you're making, but much less desirable for still brews.....

fatbloke said:

I suggested glass, as its easier generally, to make the connections and you don't need much vacuum to rack and de-gas.

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I know plastic in general doesn't work for vacuum transfers. Any chance a stouter model, such as this one - http://store.homebrewheaven.com/11-gallon-plastic-carboy-p54.aspx - might hold up?

De-gassing?

Maybe I'm being a little dense here so help me out...if you don't use enough pressure to cause whichever gas you use to go into solution in the mead then why do you need to de-gas?

I've fermented my few meads in a keg with an air lock attached...no significant pressure builds up and thus no significant gas in solution in the mead. So why would I need to de-gas?

Curtis2010 said:

De-gassing?

... if you don't use enough pressure to cause whichever gas you use to go into solution in the mead then why do you need to de-gas?

I've fermented my few meads in a keg with an air lock attached...no significant pressure builds up and thus no significant gas in solution in the mead. So why would I need to de-gas?

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To the best of my limited knowledge, a certain amount of co2 gets trapped in fermented beverages regardless of how they are fermented. It's not enough to be considered "carbonated" or "effervescent," but it's still perceptible, and often referred to as "gassy" wine. This trapped co2 can take many months, even upwards of a year, to work itself out of your wine. Simply waiting it out can produce outstanding results, not only obviating the need to degass, but the need to fine and filter as well. And you get mellowing and development of complexity to boot.

Frankly, I enjoy this gassiness in some wines/meads, but in others it definitely seems like a flaw. So, if you have the time, I see no need to degas. But, insofar as time is a factor, degassing, not to mention fining and filtering, can all become useful.

Thanks. Makes sense.

Curtis2010 said:

De-gassing?

Maybe I'm being a little dense here so help me out...if you don't use enough pressure to cause whichever gas you use to go into solution in the mead then why do you need to de-gas?

I've fermented my few meads in a keg with an air lock attached...no significant pressure builds up and thus no significant gas in solution in the mead. So why would I need to de-gas?

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When a batch is fermenting, the results, or waste products if you like, are alcohol and CO2. The CO2 only comes out once the partial pressure of it exceeds ambient pressure i.e. bubbles in the airlock. The rest of it stays dissolved in the liquid as carbonic acid.

Now with a commercial beer, the recipe/flavour have been developed so as the dissolved CO2 "taste" is part of the flavour.

With meads etc, it can give too much of an acidic "edge". Plus if you bottled a gassy mead, it's feasible that changes in external ambient pressure can cause it to come out, building up the pressure. Not good if you've bottled in standard wine bottles. It's unlikely to cause "bottle bombs", that is usually when you bottle a batch that's still fermenting, but there's still a possibility of problems or flavour issues.

You can de-gas with a "whizz stick" on an electric drill, but that has the possibility to add some oxygen, and the chance of oxidation and the negative flavour impact it brings.

You don't need much vacuum to pull the CO2 out of solution. Hence a vacuum bottler, small powered vacuum pump or even a car brake bleeding pump like a Mityvac will usually do the job, it just depends on the size of batch on the actual kit that's best to use.

fatbloke said:

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You don't need much vacuum to pull the CO2 out of solution. Hence a vacuum bottler, small powered vacuum pump or even a car brake bleeding pump like a Mityvac will usually do the job, it just depends on the size of batch on the actual kit that's best to use.

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Well, that's my daily addition to my brewing knowledge!

Pulling a vacuum on a keg should be quite easy to do. And, since they are rated for max pressures of about 130PSI as I recall they should handle a small vacuum just fine. However, the lid is designed assuming pressure pushing out so could be problematic to get a good seal. I have a couple that don't seal well until there is a little positive pressure in the keg.

Curtis2010 said:

Well, that's my daily addition to my brewing knowledge!

Pulling a vacuum on a keg should be quite easy to do. And, since they are rated for max pressures of about 130PSI as I recall they should handle a small vacuum just fine. However, the lid is designed assuming pressure pushing out so could be problematic to get a good seal. I have a couple that don't seal well until there is a little positive pressure in the keg.

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Exactly. It's easy to mistake the numbers and confuse vacuum with pressure.

Plus, as you've highlighted, it's the type of connection that might be a problem. With Glass, it's just a case of getting the correct sized rubber/cork/silicone bung, bored out to take a pipe (whether it's a flexible pvc type or a rigid glass or plastic one that has the pipe connected to that).

It's handy to see whats happening with the liquid as well. A Mityvac type device often has a small vacuum gauge as part of it, whereas small vacuum pumps and/or vacuum bottlers don't always. So you can see the bubbling of the liquid as the gas is pulled out, when the bubbling stops, so you can apply a little more vacuum to work out whether you think it's de-gassed enough or whether you want to try a bit more.....

Thanks for the great insights. At this point I'm steering away from using kegs for aging. Though I could probably figure it out eventually, I'm just not up for the requisite R&D right now. So thanks for shedding light on the logistics of keg technology. Some day soon, I will definitely have one in the house just for serving (and becoming delightfully altered).

We're selling our meads at the farmer's market, so I really need to have larger bulk aging vessels to help ensure consistency of batches. I'm looking at Flextanks (https://flextankusa.com/products.php) towards this end. I'm also looking closely at the Buon Vino Superjet for transfers into plastic (and some filtration), and the Enomatic bottle filler for bottling and degassing. I'll just have to take that extra step to vacuum transfer from bulk aging vessel to glass carboy to degas. It's extra work, but I think it will be well worth it.

Cheers -