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Serving Coffee On Tap, CO2 vs Nitrogen

Coffee on tap - grounds and a single beanWe recently received a question from a reader about serving coffee on tap.

It happened to be a question that we hadn’t addressed the issue of which type of gas to use in any of our previous posts about serving coffee on tap. So here, we aim to answer the following question:

Do you recommend CO2 or Nitrogen for serving coffee on tap? And will CO2 make it fizzy?

Both were great questions so I figured why not dedicate a full post to this topic, but before answering the question, lets give a little background on the two gasses.

Carbon Dioxide (CO2) is the gas used to carbonate beers, sodas, sparkling waters. CO2 is a naturally occurring gas (it is actually produced during the fermentation process) and it is highly soluble, meaning it is easily absorbed by liquids such as beer, soda, water, etc.

Nitrogen (N) is another naturally occurring gas, however it is far less soluble than CO2. Nitrogen is used to serve beers under high pressures, like Guinness. Beers served with Nitrogen are actually carbonated with CO2, however, when they are served, they are forced through a “restrictor” which causes the thick, frothy head that you’re familiar with on beers like Guinness and Bodingtons.

CO2 / Nitrogen Blend (Beer Gas)
A beer gas blend of 70-75% N / 25-30% CO2 will be used to pressurize and serve beers like Guinness. Since Guinness needs to be served at a high pressure, keeping the keg pressurized with only CO2 would quickly over-carbonate the beer. The blended gas prevents this.

Now, after that long aside about gasses, lets get back to the question at hand. Serving coffee on draft and what type of gas is recommended.

So which gas is recommended for serving coffee on tap?

Firstly, lets keep in mind that when dealing with coffee, we are not trying to carbonate it.

We are only using the keg and the tap as a delivery system. As a result, we will not need a very high pressure to serve the coffee – only 3-6psi.

So to answer the question: Will CO2 make it fizzy?
Any liquid that remains under pressure from CO2 for too long will eventually begin to carbonate.

The higher the pressure, the faster CO2 will be absorbed by the liquid. The lower the pressure, the longer it will take the liquid to absorb CO2 (carbonate).

That being said, CO2 is highly soluble and WILL begin to dissolve into the liquid.

Which leads us to Nitrogen (N). Nitrogen is the preferred method for serving coffee on draft.

Nitrogen is typically used at high pressures with a special tap for serving beer, but when serving coffee, we don’t need the high pressure because we’re not looking for a frothy head like you’d see on a Guinness Stout.

When serving coffee on tap, using Nitrogen at low pressure will allow your coffee to remain as it was brewed.

Either way, one thing to keep in mind will be that hot brewed coffee will always change in flavor after it cools, where as cold brewed coffee will remain stable and fresh tasting for much longer.

Want to learn more about cold brew coffee and serving coffee on draft?

The Ultimate Guide to Cold Brewed Coffee and Serving Coffee on DraftCheck out our free ebook The Ultimate Guide to Cold Brew Coffee and Serving Coffee on Draft. From brewing small batches to large batches and from serving coffee over ice to nitro coffee using a stout faucet, this book has something for everyone!How to Setup a Kegerator for Serving Nitro Coffee

About Brendan

A self employed e-commerce developer, Brendan co-created PartsLogix. In his "free time", he coaches volleyball, enjoys homebrewing, mountain biking and hacking up golf courses. Connect with him on Google+ or Twitter.

  • Matt

    Do you need to use the nitro faucet with a restirctor plate? Or, can a CO2 faucet be used?

    Is there an ideal temperature it keep the cold brew while under 3-6 psi of nitrogen?

    • Hi Matt –

      You don’t need the nitrogen faucet, in fact, most coffee shops that we work with elect to use a standard style beer tap.

      Temperature is up to you. We have shops who keep their kegs refrigerated and we also have shops that keep them at room temperature and pour them over ice. I suppose its a matter of preference.

      • Matt

        What is the shelf life like with the kegs kept at room temp? It would obviously be much less expensive up front if a kegerator or refrigerated draft system is not required.

  • CF

    What gas would you use to purge the headspace in the keg? CO2?

    • Whatever type of gas you have available. Nitrogen or CO2… whatever you’re using to serve.

  • Peter

    What if you want a frothy head?

  • Ian

    One thing that has clearly not been addressed here, but should, is presented by the question of Peter asked above… What if we WANT a beautiful cascade pour with a creamy head on top – but we DONT want any bitter carbonation? Is there a way to “nitrogenate” the coffee versus “carbonate” it? How would you advise attaining a creamy cold brew pour with head without undesired carbonation?

    • Hey Ian –

      You’re right, we do need to update the article to address this better. But to answer your question, it is possible to “nitrogenate” your using a Nitrogen (or a Nitrogen/CO2 blend) to give it the more creamy mouth-feel that you’d find in a Guinness. If you’re looking to get a creamy pour with a head, you’ll have to server your coffee that has been put under Nitrogen pressure, and it should go through a stout faucet. Stout faucets cause the liquid and the gas to go through a restrictor plate that has small holes in it. This agitates the liquid and gas causing tiny bubbles and the “creamy” mouth-feel. I hope this info helps!

      Cheers!

      • Ian

        Thanks Brendan. We have been playing with a stout faucet, but not really seeing the results without added CO2 (even the small percentage in beer gas). In other words, pure nitro + high pressure + stout faucet doesn’t really seem to get the cascade and creamy pour for coffee (it pours a fine cold brew though!). Knowing little about gasses, I was hoping there was an easier answer to whether you can get a cascade and that beautiful creaminess and head without any use of CO2… seems my experiments shall continue for now! Cheers

        • Rather than running strictly Nitrogen or CO2, have you tried “beergas”? This is typically a 70/30 mix of Nitrogen to CO2. The CO2 contributes to the carbonation while the Nitrogen provides the creaminess. Using a stout faucet, the carbonated beer is agitated through the restrictor plate.

          Give it a shot on your next tank fill. I think it might help you get the results you’re looking for.

  • Matthew

    Great article! Thanks for sharing your knowledge.
    What is the shelf life of cold brew once keg’ed and pressurized? Obviously there are several variables;

    1: sitting at room temperature
    2: kept cold in a kegerator
    3: Room temp just with Nitrogen
    4: Kegerator with just nitrogen
    5: room temp with “beergas”
    6: kegerator with “beergas”

    • Hey Matthew –

      Thanks for the comment and sorry for the late reply. I think most of the questions really depend on how much of a coffee connoisseur you are. For my homebrewed coffee, I put it in a keg and usually try to go through it in 30-45 days. If you were a coffee shop, I’d suggest serving it in 1/4 that time (or even less).

      Another factor to consider if you are keeping it under pressure is how you’ll be serving it – from a regular tap, or from a stout faucet (to pour like Guinness).

      I know this didn’t necessarily answer your question, if you’d like to discuss more, feel free to contact us using the contact form on our website or through Twitter, Facebook or Google+.

      Cheers!

  • Tiffany

    Thanks for this article and comment section. The 30-45 day timeframe you refer to, is that refrigerated or not? We will serve cold brew on ice and would obviously prefer not to have to refrigerate the keg as well provided it would last a couple of weeks.

  • Hi Tiffany – what I’ve come to realize is that times vary based on personal expectations/requirements/taste/etc. I only cold brew personally (I don’t sell or distribute coffee) and every coffee shop owner who I’ve spoken to has slightly different criteria on their coffee going from keg to glass.

    Personally, when I fill a keg with cold brew coffee, I keep it refrigerated and will leave it up to 60 days. Does the flavor change? It does a bit, but I’m no connoisseur, so I really don’t mind.

    If I were serving commercially, I’d likely get a smaller keg or just make sure that I was filling with fresh coffee daily.

  • Erick

    I’ve found that carbonation impacts the flavor of the coffee (not in a good way). Have you noticed any flavor impact/change when serving under a CO2 / Nitrogen Blend.

    • Hey Erick –

      Not sure why I’m just seeing this comment. But to answer your question, yes CO2 does have a negative effect on the flavor (in my opinion) – it gives a bitterness/tangyness that is not great.

      With the CO2/Nitrogen blend, I have not noticed the same flavor change. I am however pouring through a stout faucet which gives it a good creamy mouthfeel – not sure if that helps to disguise any off flavor the CO2 in the blended gas may contribute.

      I haven’t had a chance to do this yet, but I’d like to get 3 small kegs full of coffee and pressurize and serve each on different gas:

      1. CO2 Only
      2. Nitrogen Only
      3. CO2/Nitrogen Blend
      • Tiffany

        And why didn’t you choose nitrogen only to begin with?

      • John

        Brendan, did you preform your experiment with the three gases?

        • Hi John –

          I have served on CO2 and and a 75/25 Nitrogen/CO2 blend. Huge difference between the two, especially after the coffee sits in the keg for an extended period of time.

          I haven’t got a tank of 100% Nitrogen yet, but I’d assume that it would help the coffee maintain its original flavor, consistency and mouthfeel for a much longer period.

          • John Cameron

            I have beer gas and CO2 available in two separate tanks but would prefer to not have a third for pure nitrogen. What do you think contributes to the mouthfeel? I have a suspicion that pouring with pure nitrogen, even with a stout faucet+restrictor plate would eliminate any head and creamy texture. Thoughts?

          • To be honest, I’m not too sure about that (until I try it). Part of me thinks that infusing with pure nitrogen and serving at 30+ psi will still put enough gas into the liquid to give it a head and cascading effect. Though speaking in terms of beer, the CO2 is what is absorbed into the beer and is agitated on its way through the restrictor plate when leaving the faucet.

            I think 100% nitrogen would require:

            1. a decent amount of time under pressure to allow the nitrogen gas to be absorbed into the coffee
            2. possibly being poured above the normal 30psi

            Hope this helps! If I try this out, I’ll be sure to write about it.

          • Another thought:
            With 100% nitrogen, if you have a CO2 tank handy as well, you can always infuse the keg with CO2 for a limited amount of time to get CO2 into the liquid. However, doing this will be a guessing game as to how much of each gas is in the keg. This could be a way to “revive” a keg if 100% nitrogen did not provide a creamy, frothy head and a cascading effect.

            Cheers!

  • Meenal Viz

    Thank you for all your information and insight into cold brew!

    You’ve already mentioned that coffee lasts around 30-45 days. However, I would like to bottle my coffee and store it. I am obviously looking for a long shelf life once bottled.

    Would I need a bottling gun to keep oxygen levels as low as possible or are there any other methods I can use to keg & bottle my coffee with a long shelf life?

  • Jesse

    This article has been a great help! I’m trying to do this at my coffee shop, and I’m using 100% nitrogen. Do you have any suggestions for the best way to nitrogenate the coffee? Do I just let it sit for a few hours, or days? Or should I be agitating it as well? I’ve also read about a carbonating stone, which was totally new to me. Thanks so much!

    • Hey Jesse – glad the article helped!

      As far as nitrogenating the coffee, if you’re serving via a stout faucet, use a 75/25 beer gas blend. I usually pressure up to about 30psi and let the keg sit for 3 days or so. You could optionally use CO2 to get gas into the coffee and agitate it, then hook it up to beer gas for serving.

      • John Cameron

        Doesn’t the beer gas produce off flavors of carbonic acid? Isn’t the goal to serve coffee that isn’t carbonated?

  • Dayne

    Hi,

    Thanks for the amazing insight into Nitro coffee. I am. Based in Australia and. Would like to set up my roasted coffee into a Nitro format. I have the recipe to do this but am not sure on the exact method on how to do it.

    Is there any info you could assist with? Maybe I can purchase everything I need from you?

    Thanks

    Dayne

    • Hey Dayne –

      We can definitely help you out with whatever you need. Feel free to email us any specific questions you might have.

      Cheers!

      • Dayne

        Hi Brendon,

        What is your email address so that I can email you with a few questions?

  • Andrew

    Great article. I would like to know what ratio would you suggest for mixing cold brew concentrate and water.Thanks

    • Keg Outlet

      Hi Andrew – it really depends on how heavy you make the concentrate, your preference for the strength of your coffee, etc.

      I’ve seen concentrate mixed at any of the following ratios with water:
      1 part coffee concentrate to 1-3 parts water

      When mixing with milk, you tend to see more of a 1 to 1 ratio.

      Hope this helps!

      • Andrew

        Thanks Brendan for the reply. I was actually
        Talking about nitro brew sorry for not being
        Clear earlier. So if making nitro brew do we
        Still dilute with same ratio or use the
        Concentrate. Also good luck with chase
        Grant I did vote for you 247. I am also participating
        .29th parallel coffee & tea in Fairfax va
        Thanks and goodluck

        • Brendan

          Gotcha. Generally you’ll dilute it a bit. Concentrate looks cool if you serve it on Nitro, but that will likely be WAY TOO STRONG and too high in caffeine to serve.

          The few shops I’ve visited typically serve nitro coffee a bit stronger than they’d serve a typical cup of coffee, however not at the full concentrate level.

          Thanks for the vote! We appreciate it!

          • Andrew

            Thanks Brendan once again Good luck

  • Aaron Pierson

    Being a homebrewer that is now selling coffee, I want to add my 2 cents to this. Use pure nitrogen. Crank it to around 38 psi and it will do the bubble cascade thing for you in the glass, I promise. Almost immediately, but I still recommend a good shake or two for the keg. Don’t use beer gas or CO2, as they will both assist in an acidic flavor (Carbonic acid does that. Seriously, that’s how you properly add 100% of the chalk to a mash.) Next up is how to cold brew. Do not use the Japanese method of hot brewing coffee over ice. Once you add heat, you have introduced an acidic compound to your coffee. Don’t bother with 50% hot and 50% cold brew, it’s a waste of time. The correct way to do it is about 3/4 of a pound of coffee to a gallon of water, cold steeped at a rough grind for 12-14 hours. Rough filter into a vessel, then fine filter from there. Should take about 20 minutes per gallon if you are using basic equipment (nylon filter for rough, layers of coffee filters for fine). Once filtered, that should be the last time the beer sees oxygen until serving time. Pressurize at 38 pounds with pure nitrogen, and pour from a decent stout spigot. Use low acidity coffee for best results, my personal favorite was a single source Peruvian bean.

    Or, if you want instant gratification: get a whipped cream dispenser that uses Nitrous. Cold brew any coffee you want, add a cup to the whipped cream dispenser and serve it from there. If it tastes better, upscale.

    • Keg Outlet

      Hi Aaron –

      Thanks for sharing! Definitely going to try bumping up our nitrogen PSI. Definitely agree with the cold brew – don’t brew it hot – changes the taste/flavor too much.

    • John Cameron

      Aaron, why do you suggest shaking the keg? Is it simply to mix up the coffee? Or do you think it increases absorption of nitrogen into the coffee? I understand with CO2 this causes more CO2 to go into solution (aka force carbing), but I question this practice with nitrogen due to the low solubility of nitrogen in water. What are your thoughts?

      • Aaron Pierson

        It’s honestly just to make it pretty when it pours. The nitrogen will be suspended in solution under high pressure. As soon as it is poured it will make the pretty little bubbles in the glass. Completely unnecessary if you just want cold coffee, and it will slowly happen without shaking. But my wife likes a pretty pour, so I make sure it’s ready to go without having to wait a week or two.

        • John Cameron

          I disagree. With enough nitrogenation it definitely effects the mouth feel.

          • Aaron Pierson

            What psi are you pushing it at? I’ll experiment with it.

          • John Cameron

            Currently about 45 psi. I use 38 psi for beer. I have ~10 foot beer lines and am at ~5,000 ft above sea level.

          • Sinan Turunc

            What is enough? How many days you mean my friend?

          • John Cameron

            I wish I had a better answer than ‘it depends’. I would say with a carbonating stone 1 day should be sufficient, and at day 3 it was noticeably smoother. By week 2 it was once again noticeably smoother than day 3. Day 1, 3, and 14 were all delicious.

          • Sinan Turunc

            İt seems one week in cooler it should stay.Thank you för your reply.what kind öf filter you prefer för brewing ör method för nitro cold brew?

  • I just tapped my coffee keg with nitro and tried a pour and it came out flat. How long should I wait? I read you should shake up the keg first. Any tips to what I am doing wrong?

    • John Cameron

      What gas (CO2, nitrogen, or blend) are you using to dispense? What psi is the output of the regulator set to; more importantly, what is the flow rate (oz per sec)? Are you using a stout faucet with a restrictor plate?

      • I am not sure what the blend is. I have it set to 32#. Not sure what the flow rate is, how do I find that? I am using a stout faucet, which is brand new, I think it has a restrictor plate. This is all new to me.

  • Coffee is pouring great and we are getting a lot of complements. The beer gas guy thinks 35 lbs may be to high, anyone tried lower pressure?

    • Keg Outlet

      If it’s pouring great, leave it!

      We’ve been doing tests with 100% nitrogen at 40psi and it has been fine.

      Just keep in mind that with a beer gas, if the keg is under pressure for an extended period (a couple days or more) the coffee/beverage can begin to take on carbonation.

  • I think I need a manifold so I can pressurize 2 kegs at once. Plowing through the coffee and we don’t have time to wait a couple of days with no coffee. I’m thinking a 2 outlet manifold with a new hose and ball disconnect. Can you help me out with this?

    • Keg Outlet

      Absolutely! Shoot us an email at info@kegoutlet.com and we’ll see what you need to get going.

      Cheers!

      • Sinan Turunc

        İ saw the Mail adress and i asked few points about nitro.would be very glad if you can help. Thnx a lot

    • Sinan Turunc

      How fis you brew your coffee? What kind öf filter Did you use?

  • Daniel Browning

    So I’m getting started on a nitro setup in my coffee shop and I’m having initial troubles with the carbonation balance. I was using 75/25 beer gas and had a beautiful cascade after a few minutes of shaking the keg. I was fairly happy with that for about 24 hours until the keg carbonated. Then it tasted terrible. What’s the best way to balance the carbonation issue? Smaller kegs? Turn gas off at night? Pure nitrogen after an initial co2 exposure?

    To compound my problem. I live very remote and my gas supplier takes about 2 weeks to restock gas. I had a leak and ran out of mix gas before I could do any experimenting. I’m now using straight nitro @30psi and have zero bubbles but the taste is great. I did a 5psi pure co2 exposure for 6 hours and then vented that and connected it to the nitro. There was some bubbles but not much and it already had a carbonated taste.

    What’s the best practice for balancing cascade and taste?

    • John Cameron

      You need 100% pure nitrogen. Any CO2 will eventually impart carbonic acid and make the coffee taste terrible. The off flavors occur in usually only a day or two in my experience.

      You need to increase the pressure. I run mine at 38-45 psi. My coffee supplier also has installed a carbonating stone attached to the gas in side of the corny keg effectively continually carbonating the coffee each pour.

      • Daniel Browning

        Thanks John. I can definitely see that being the case, and I’m completely ok with that plan. But my (mis?)understanding was that the co2 is necessary for the cascade and a creamy head since the restrictor plate removes the co2 and creates foam. I can try to raise the 100% nitrogen pressure to 38psi as someone suggested but at 30psi I’m not seeing much sign of a cascade.

        What at the visible qualities that you get with 100% nitrogen? And at what psi? I’m assuming time has no impact since the nitrogen is not soluble given a short amount of time.

    • Keg Outlet

      Hey Daniel – to reiterate what John said, nitrogen is the way to go.

      If you are stuck using beer gas, my recommendation would be to make sure you go through the entire keg each day. We’ve got customer who go this route – using beer gas because they’re able to achieve the creamy, cascading head effect much more quickly than with nitrogen alone.

      But again, if you have the option, 100% nitrogen is the way to go.

      Cheers and good luck!

      • Daniel Browning

        Thanks for the quick response ya’ll. . I prefer 100% nitrogen since this is much more available to me. I had some questions but I think John might have edited his post because they are answered once I reread the post.

        I will get some of those stones and make pressure adjustments.

        • Keg Outlet

          Sounds good! Best of luck!

          We’re working on a new eBook specifically geared toward draft coffee (both flat and nitro). Hoping to have that done soon.

          Cheers!

          • Daniel Browning

            I look forward to it, and will check out your site as I’m shopping for more equipment. Thanks again for your help.

            Im also working on a simple inline filter that lets me pressure transfer and filter from my Brewtech chronical right into a keg. Perhaps I can find a place on your site to share that setup. Any advice on what size micron filter I should use to not clog the restrictor plate?

          • Keg Outlet

            Would love to see your inline filter idea!

            As far as micro level – We’ve heard 50-100 micron from most. Our tests right in the middle of that range has yielded very clean coffee.

          • Daniel Browning

            I want to start by saying I have not tested this extisively and I’m not advising anyone to try it except at your own risk. But it works fantastic for me and saved countless amount of time waiting for a gravity drip.

            In this setup I drain from my fermenter into an empt keg(Waiting on fittings to pressurize the fermenter and skip this keg). The straining bag is the first round of filtration but I might get rid of those at a later date. The liquid out line is connected to an inverted filter housings that contains a 30 micron sediment filters. Then the out line of the filter goes into the empty key and the contents have been filtered to whatever micron level filter you choose to use. Once the liquid lines are in place set the pressure regulator @3psi and connect it to the first keg. Turn on the gas pressure and it will take about 3 minutes to filter 5 gallons of coffee

            The housing is designed to be mounted any position and putting it upside down allows to easily drain the contents of the housing. Important to note that I flush the new filters with at least 10 gallons of water before using them and 5 more between uses. I have used it for about 40 gallons so far and don’t expect much more out of a $3 filter.

            This is just a basic keg transfer with a water filter in line. I’m tottaly open to any criticisms of it, but I don’t lead a life that allows me the pleasure of waiting to gravity feed 40+ gallons a Week.

      • John Cameron

        @kegoutlet:disqus, I posted a lengthy response explaining the process in detail, even with a video, yet after I posted it, it was flagged as ‘awaiting approval’ by the site moderator, now I don’t see it at all. What happened?

        • Keg Outlet

          @ClimbrJohn:disqus – That’s odd, I don’t see anything in moderation. I’ll have to login Disqus directly and see if there is anything stuck in there.

          • John Cameron

            Yeah, I just tried to add another comment and it states: “Hold on, this is waiting to be approved by Keg Outlet.”

          • Keg Outlet

            We got the email that you commented – just don’t see anywhere within the Disqus admin where “Pending” comments are held. Would think it would show up and be easy to click to approve.

            Still searching….

          • Keg Outlet

            Figured it out! Comment is online now.

        • Todd Gun

          Hi John. So I have a 2.5 gallon keg (it’s not Cornelius brand), I’m wondering if the lid is standard size. Because I want to buy a carbonating stone lid, I think this is the easiest way. Thanks.

  • Daniel Browning

    John that is beautiful and I will use it as my personal goal. I can make enough the let it sit for a day or 2 but 3 weeks is about a 120 gallons of coffee so I’m not prepared to have 24 kegs sitting around. I’ll test my results when my stones arrive tomorrow.

    Keg outlet sorry to hijack the thread but I really appreciate the great info.

    • Keg Outlet

      Hey @disqus_bKuZjvvvlo:disqus and @ClimbrJohn:disqus – You’re not hijacking anything. We appreciate all the knowledge and info that is being shared. That’s why we wrote our first ebook and why we’re in the process of putting another one together.

      We just hope that you all will consider http://www.kegoutlet.com when looking for equipment and information!

      Cheers fellas!

    • John Cameron

      Thanks! The roaster I got my keg from force carbonates the keg with the carbonation stone (100% nitrogen) in about a day and it was wonderful even on day 1. When I picked up the keg they suggested for the first couple days to shake the keg to expedite nitrogen absorption and bleeding off the headspace of the keg to force additional nitrogen into the keg and through the carbonation stone. I presume this is how they force carb. Refrigerate keg, fill keg with 40 psi nitrogen, bleed off headspace, repeat.

      • Daniel Browning

        Yeah I was gonna use tubing and some compression fittings to put the carbonating stone on the bottom. I was under the impression that the nitrogen was not soluble enough to penetrate the coffee on a short amount of time but I’ll set a keg to the side and see how time affects the cascade.. I was planning on brewing under light pressure and will put it under 40psi once I get it into kegs.

        • John Cameron

          I was under that impression too, however none of the people who’ve told me that have ever tried it. So in practice, it seems to work. The local roaster says the carbonating stone is ‘the trick’ and they’ve experimented for quite a while. Let us know your results! I’ll be carbonating a home-brew beer via nitro in the next few months and hope to apply what I’ve learned with coffee.

  • Michael Ross Rideout

    Guess I’m a little confused… So this carbonation stone is needed?? Can someone post a picture of what this looks like installed?

    • John Cameron

      You would basically have a

      diffusion stone (can’t find it on kegoutlet.com)

      http://www.morebeer.com/products/diffusion-stone-5-micron-carbonationoxygenation.html

      attached to a dip tube or vinyl tubing that reaches to the bottom of the keg from the gas in poppet:

      http://www.kegoutlet.com/kp326pll-liquid-dip-tube-beer-out-pin-lock-keg.html#PhotoSwipe1440194573416

    • John Cameron

      You would basically have a diffusion stone attached to a dip tube or vinyl tubing that reaches to the bottom of the keg from the gas in poppet.

      I have links in another comment, but the comment is awaiting moderation for some reason.

      • Michael Ross Rideout

        Thanks John. I believe I may have commented on one of your YouTube videos. If you want to post a reply there maybe that would be easier. Question is adding this part a pretty straightforward process? Also any links or recommendations on which one to buy? With this part does that eliminate the process of charging?

        • John Cameron

          I think it’s pretty straight forward if you’ve setup a kegerator. A few feet of vinyl tubing, some hose clamps and a diffusion stone. I’ve heard of people substituting the vinyl tubing for a stainless steel dip tube and welding the diffusion stone onto it for a more durable solution.

          • Michael Ross Rideout

            I see, so you’re basically connecting this to the gas in nipple inside the keg, running the vinyl tube to the bottom of the keg then attaching this fitting at the end? So in theory the gas is causing bubbles in the bottom of the keg when entering?

            Does the keg have to be vertical or can it be laying on its side?

          • John Cameron

            You got it! I would imagine even using just vinyl tubing would make a difference, but adding the diffusion stone make the bubbles .5 micron to allow them to easily absorb into solution as they travel upward.

            I would presume you would want it vertical.

          • Michael Ross Rideout

            So you aren’t charging with CO2, just bleeding off the O with N2 after filling?

          • John Cameron

            Correct.

            You don’t want any CO2. It’ll taste terrible in a day or two. From what I’ve read, it’s the carbonic acid from the CO2.

            To force carb a keg of beer/coffee you pressurize the keg, shake until you don’t hear any more sounds of gas entering the keg. Repeat every few hours. With a diffusion stone you can shake and keep bleeding off the headspace forcing gas through the stone and the bottom of the keg. You definitely want your beer/coffee as cold as possible to increase the gas solubility of your liquid.

          • Daniel Browning

            WOW!! Carbonating stones for president!! That made all the difference in the world. Instantly had great cascading and head and it did get better after a day.

            I would love for them to be available from a small business (hint hint) but I bought them from Amazon. They had a .5micron carbonating stone for about $12. They have a 1/4 in hose barb, but my 10 kegs have 2 different sized tubes on the inlet side. The small one will need a 3/16 ID vinyl tubing and the larger will need a 1/4 ID. Roughly 24″ long . They are a very short tubes and do not have a barb so you will need a hose clamp. I recommend a “spring hose clamp” since they are difficult to get a screwdriver in the high and tight corner of the keg. If your vinyl hose is curly just connect it and fill your keg with hot water and hook it up to 40psi for a minute and it will straighten out. The you just fill your keg with coffe like normal and connect it to 40psi nitrogen. Bleed off the air and the connect it to your tap. You should hear the bubbling hose in the keg. Once you connecti it there will be a reasonable foam almost instantly and it does get bette towards the end of the keg.

          • Daniel Browning

            I should also say that my next test is to connect the keg to 5psi nitrogen and let it bubble for a few minutes to see if that force carbonates a little better before the first pour. I bought a 200# bottle of nitrogen for $15 so it’s not gonna hurt my feelings to use it to purge for a while.

          • John Cameron

            Yay! So happy to hear you got it working! =)

        • John Cameron

          I think charging = force carbing? So you would still need to initially nitrogenate (most would call this carbonate, except we’re using nitrogen, not carbon dioxide). It just happens in minutes / hours with a diffusion stone vs. days with ‘force carbing’ and waiting for the nitrogen (but in most cases CO2) to be absorbed from the top of the coffee / beer where the headspace of gas is. The diffusion stone force the gas *through* the liquid and the bubble are super tiny as they float up through the liquid and are much more easily absorbed.

          • Keg Outlet

            Another option if you want to send the nitrogen through the liquid rather than into the headspace (not to complicate things) would be to lay the keg on its side with the gas in diptube on the ground side when gas is initially added. When doing this, you’ll hear a gurgling sound from your keg.

          • Michael Ross Rideout

            So you’re saying basically install your hook ups in the opposite order (in/out and out/in) and run the keg on its side?

          • Keg Outlet

            No, was just saying to lay the keg on its side as you introduce the gas. Return it to vertical for serving.

          • Michael Ross Rideout

            So charge the keg on its side using only NO2? For how long and at what presser?

            (So we don’t get side tracked, my goal is to have that nice foam pour through my stout tap… Like Guinness)

          • Keg Outlet

            Honestly, I charge the keg at my house with it standing vertically. I do about 40psi for 24-48 hours. I get a good pour and frothy head with each pour.

            Putting the keg on its side was just a suggestion if you want to know that you’re sending nitrogen through the liquid (rather than into the head space).

          • Michael Ross Rideout

            And you charge with 100% nitrogen correct ??

      • Keg Outlet

        I know… You’d figure our site would just let your comments through already! I think it holds it whenever there are external links.

        …. I can’t believe you linked to MoreBeer from our site! 😉

        • John Cameron

          =( sorry. I looked for quite a while on your site for a diffusion stone. Do you guys sell them?

          • Keg Outlet

            Unfortunately, we don’t. So we’ll let it slide this time.

            Cheers!

      • André Boldori

        The same diffusion stone can be reused how many times? Many thanks

        • Keg Outlet

          It should last for years if cleaned and maintained well.

          • André Boldori

            Many thanks

  • Joseph Pedrotti

    I’m working on a NITRO Coffee setup for a customer of mine, they sell so much NITRO Coffee that they do not have to for a 24 hour soak time, and eaven when they do soak the keg the product starts our nice cascading is great but boom it stops so it is just inconsistent. I am thinking about injecting nitrogen into the line just below the tower what are you thoughts in this idea. Think inline NITRO injection could this solve the problem

    • Keg Outlet

      Hey @josephpedrotti:disqus – Honestly, we’ve never tried what you’re suggesting. It may work, but I can’t guarantee it one way or the other.

      We’ve found that after pressurizing the keg, agitating it really helps – especially when you get 1-2 good pours, then just flat pours.

      If you proceed with your suggested solution, we’d love to hear your results since it is not something that we’ve tried yet.

      Cheers!

  • Tony Huang

    Hi, Does anyone experience problem with no foam from the keg? We just learn to start our nitro-coffee. The keg is charged with nitrogen with 30psi constantly but we were unable to pull a proper shot because no foam at all! (problem is, we have first one successful and the second and the following one just has no foam!) Please help

    • Keg Outlet

      Hey Tony – Try turning the following:
      – Turn the gas up to 35psi
      – Shut the gas off at the shutoff valve and disconnect the keg
      – Agitate the keg (gently lay it on its side and rock it back and forth for 5 minutes)
      – Re-attache the gas line and open the shutoff valve

      Try serving again after completing the above steps.

      • Tony Huang

        Thanks for the advice. It does help. The first half pour is just as same as before until reach to half of the glass. A sudden pop sound occur,gas mixture finally come through. Very strange. why??

      • Tony Huang

        I think I found the reason, some tiny coffee grind was found at the bottom,guess it caused the blockage

  • Vikram Jadhav

    I am confused a bit… When serving Nitro Coffee what is it actually infused with? … Nitrogen or N2O ( Whip cream cartridge) . What would be the result for both?

    • N2 but I’m also curious about whether N2O would work

      • Doyee5

        Nitrous would dissolve out of solution.

        • I’m using N2O in a cream whipper and it works great

  • Tony Huang

    Hey guys, I finally able to get the taste right. However, How did you get such a thick foam?? (2cm),I charged my keg for 48 hours,40 psi, but never exceeding 1cm 🙁

    • John Cameron

      Make sure the coffee is cold; < 40º F is ideal. The colder it is the more soluble gases are. Use a carbonating stone. If not available, shake the keg every for a few seconds every few hours and before pours. I would also up the pressure to 45 psi; that's where I keep mine. (See my previous posts if you want to see a video of my results. Lots of great info on this page.)

  • Abe

    Hi @ClimbrJohn:disqus, @disqus_bKuZjvvvlo:disqus, @brendo234:disqus . I have been going back and forth through this thread of comments and haven’t figured out what is best approach to figuring out the no foam solution. I have my stout faucet, 100% nitro tank and my cold brew. The test I’ve done so far:

    – Direct pour ( Got a flat cold brew)

    – Pumped Nitro and left for 6 hours at 45psi ( Got a flat cold brew)

    – Without pumping any Nitro, I shook the keg ( Got cascade and creamy head for the first pour and started loosing pressure to the point of no liquid from faucet)

    – Pumped Nitro at 45psi while rolling back and forth the keg for 5 minutes ( Got cascade and creamy top but almost no pressure from the faucet permanently )

    I’m not sure why I would loose pressure if I am purging the oxygen before reconnecting Nitro and the out line.

    Either way here is my question…. To avoid the whole shaking for each keg and/or pressurizing for 3 days, John is recommending the carbonating stone. This looks like an interesting solution except for the research i’ve done is:

    – Do I get a “Carbonating Keg Lid” or just a “Carbonating Stone” and attach it to vinyl tubing to the in line of the corn keg?

    – Do I use the “Carbonating stone” to carbonate the cold brew permanently (meaning it will always be attached even when dispensing the nitro coffee out of faucet) , or just for a 24 hr period before I start to pour out of the faucet and just pump Nitro through the in line for pressure?

    – Do I continue to pump Nitro at 45psi WITH the carbonating stone?

    Sorry, this might be a long post, but I’m a bit confused since this seems to be a common problem and there is so little information as to what a definitive formula to get nitro coffee with creamy foam on top and using 100% nitrogen.

    I would appreciate any help I can get. Thanks!

    • John Cameron

      I’ve had the best luck with leaving the carbonating stone permanently installed. This allows the coffee to be continually nitrogenated and agitated with each pour.

      • Abe

        Ok thanks @ClimbrJohn:disqus. Whats the # of psi you let through when you pour? And whats the number of psi you use prior to pouring ( the 24 hour period your roaster does ) ?

        • John Cameron

          Not sure I fully understand your questions but I set the regulator at around 45 psi. Anywhere around 35-50 psi should work, but you might need to adjust this to preference. For beer you typically want a pour rate of 2 ounces per second and this is what I shoot for. You can adjust this by altering the length of the line from keg to tap. The friction in the lines and the restrictor plate in the stout faucet dramatically slow down the pour rate, which allows you to increase the gas pressure going into the keg.

  • Rhiannon Tenney

    Wow, I never knew that people used Nitrogen for serving coffee. It is interesting that we use gas to serve our beverages. I would have thought that CO2 would be really helpful for serving coffee. I will make sure I am aware of what gas I am using to serve my different drinks.

  • Mike Lamont

    Hey John Cameron I have read the whole blog and this has been very helpful. I was curious what the ratios were that you use for the coffee? I am using 3/4 pounds of coffee for every gallon of water I was curious how much dilution you put into that or do you just serve concentrate?

    • John Cameron

      @mike_lamont:disqus Glad to hear! Sorry, I’m not much of an expert in actually brewing the cold brewed coffee. I’m more of an expert in creating espresso and beer. However, your ratio does sound about right.

      Given the choice, I would suggest making it stronger; it’s always easy to add more water to the keg after the coffee has been brewed.

  • Mark

    Hi Guys

    This has been a very useful discussion, Ive been trilling the Nitro brew for a while now, and have put carb stones in my kegs as mentioned here, which works well without shaking the Keg….however im having trouble with the coffee pushing back through the inlet terminal into the Nitrogen hose, any suggestions to stop this?

  • Will

    is the setup the same for charging a keg and for serving from a keg?