In episode 9 we discuss the types of gas that can be used in draft systems and how which type of gas is best for different beverages. We go over why certain gasses are used in some applications and not others as well as the difference between the 2 main gasses and why we sometimes blend the 2 gasses.
Highlights & Takeaways
3 Main Types of Gas
- Carbon Dioxide (CO2)
- Nitrogen (N)
- Beer Gas (CO2/N blend)
What gasses are best for different types of beverages.
Purity levels for gasses
Additional components that can be used in gas systems: Gas Blenders, Nitrogen Generators, Gas Filters
There is a 4th type of gas that could be mentioned and that is Argon. Argon is typically used in wine applications and is generally a bit more pricey, so oftentimes is not worth adding to a draft system.
Episode 9 Transcript
Hey there and welcome back to the Drips & Draughts podcast. I’m Brendan Hanson and today we’re going to be talking about types of gas.
No, not that type of gas. Though that probably would make a pretty funny episode and I could get my cousin, The Honey Badger, on here who is somewhat of an expert in the art of flatulence.
The type of gas we’ll be talking about today is the gas used in draught systems. There are a few different types of gas that can used within a draft system, so we’ll go through each of those types of gas today and when they should be used and how they should be used and what beverages they should be used for.
Before we get into that, let me take a moment to say thanks to everybody whose been downloading this podcast, sending us emails with feedback. We really appreciate all of the feedback that we’re getting, whether it be positive or negative, things that we can improve on.
We definitely appreciate it. This is our first time doing a podcast. We’ve almost got an dozen episodes under our belt now and we’re learning every day. Keep the feedback coming, let us know what you want more of, let us know what you want less of.
One thing that we’ve got a lot of mixed feedback on is the length of episodes. Some people say, “You’ve got to have an episode that is at least 30 minutes long otherwise it’s no good for my commute”. Then, other people say, “Keep them under 10 minutes. I like them short. I just want to know about a single topic. I want it short and concise and that’s all I want is 10 minutes or less.”
In hearing that, we’ve obviously got a couple of different formats that we’ve done so far. There’s the podcast that I do as an individual and then we also do the interview style. It seems that the podcasts that I do individually are starting to take that shorter format, 10 minutes. About 10 minutes. The interview podcast seem to be taking that longer style format getting up towards 30 minutes.
With the mixed feedback we’ve received in terms of episode length, I think we’re going to continue doing podcasts that range in that 10-minutes to 30-minute range. In fact, one podcast that I listen to, The Curious Minds podcast, they do a good job of this.
They do a very long format that goes 30 to 45 minutes and then they recently started doing what they call “Shorts”. They’ve got these episodes that they call “Astronomy Shorts” that are basically just five, six, seven-minute episodes.
I actually really like these short episodes because my commute has become very, very short. It’s about five minutes. I turn one of these on when I am driving home or driving to work and don’t happen to have the radio on. They’re perfect for me.
Let us know your thoughts. Send us an email to firstname.lastname@example.org and let us know what you think in terms of episode length. Check out the Curious Minds podcast as well. They’ve got a great variation in terms of show length and while you’re there, you might actually learn something too. Check them out, it’s on iTunes or you can find it at cmpod.net.
All right, let’s get back to this episode and the types of gas that can be used in draught systems. There’s really only two types of gas that are used and sometimes you can say a third, which is a blend of the two most common gases, so three types of gas for the sake of this episode.
We’ve got carbon dioxide, we’ve got nitrogen, and we’ve got beer gas, which is a blend of carbon dioxide and nitrogen. First up, let’s talk about carbon dioxide. If you’re coming from the beer industry or the beer world, this is the most common gas that is used for draught systems. This is the gas, in fact, for draught systems.
Since all beer is carbonated, the use of CO2 provides two purposes: one, it helps push the beer out of the keg, and two, the CO2 in the headspace of the keg or the serving tank helps to maintain proper carbonation levels of the beer that’s being served.
Carbon dioxide is always used in beer systems when serving draught beer, but what else can it be used to serve? We highly recommend that you don’t use any CO2 when you’re serving coffee. When you’re looking to serve coffee, make sure your getting nitrogen. That’s going to be your gas of choice.
Carbon dioxide can be used to serve many other things as well. We’ve served sodas with carbon dioxide, we’ve served sparkling waters, we’ve made and served sparkling waters. It can used to serve teas, sparkling teas. We also have a lot of clients who use carbon dioxide to serve kombuchas. Really, CO2 can be used to serve anything you want.
Just keep in mind that carbon dioxide is very soluble in liquid. That whatever beverage you might be serving under carbon dioxide pressure, it will eventually carbonate and you will get a sparkling water, soda, tea, coffee. Whatever is under that carbon dioxide pressures is eventually going to carbonate.
One other thing you might want to notice is that carbon dioxide is a naturally occurring byproduct of the fermentation process. So that’s why carbon dioxide is a common component used in beer. Same with Kombucha, Kombucha is a fermented tea, it naturally develops a combination itself. Serving Kombucha with carbon dioxide, under carbon dioxide pressure is common. It’s not really going to change the taste, or the flavor, or the profile of that Kombucha.
Next up we’ve got nitrogen. Nitrogen is a gas that’s very insoluble compared to carbon dioxide, which is very soluble in liquids. Nitrogen is very insoluble, meaning that it’s hard to get the liquid to take on the Nitrogen itself. That’s why Nitrogen is recommended when serving coffee. You’re not going to necessarily carbonate or nitrogenate the coffee as easily as you could carbonate the coffee if you were serving under Nitrogen pressure.
Some of you are probably thinking, “But wait, I want to serve nitro-coffee. I want to serve coffee that’s pouring like Guinness, and has that rich head.” We’ll get to that, but right now talking about nitrogen back in a standard application or in a beer setting, you typically using nitrogen for one of two purposes. One, is to allow a really high pressure when dispensing the beverage through something that’s restricted like a style faucet. Two, to allow enough gas pressure or a high pressure to push the liquid over a long, long length of beer line.
I’m sure many of you have been to a bar where you’ve seen a room in the back that’s got a bunch of kegs and then a bunch of beer lines that run overhead. Usually through a tube that’s of course refrigerated. Sometimes these things go 60, 80, 120 feet from the keg room all the way up to the bar. That’s when nitrogen would be used in combination with carbon dioxide to push the beer that length.
In order to do that without either losing carbonation in the beer or over carbon in the beer, nitrogen is generally mixed with carbon dioxide in this case. That’s where the term beer gas comes from. Beer gas allows kegs to be connected to a draught system under higher pressure without over carbonating the beers.
What if you want to serve nitro-coffee, can you use beer gas? That answer is tricky. The answer is, yes. You could use beer gas, you could use any gas you want. Just keep in mind that over time and while that coffee is under pressure from the beer gas, it’s eventually going to start taking on carbon dioxide. It’s going to carbonate and you’re going to start to get that acidic bite that combination has. That’s definitely something you want to add to your coffee.
When trying to serve nitro-coffee, rather than using carbon dioxide or rather than using a beer gas, you should use 100% nitrogen. Since nitrogen is not as soluble in coffee, or in any liquids for that matter, that makes making nitro-coffee a bit of a challenge. Because what you need to do is, you essentially have to make a liquid absorb a gas that doesn’t want to be absorbed.
Now there’s plenty of ways around that, and we’ll talk about those at greater length in future episodes. For now, let’s just say with coffee, use nitrogen. Nitrogen is most commonly used in beer gas plants. However, with the growing popularity of draught coffee and nitro-coffee, 100% nitrogen being use to serve products on draught is becoming much, much more common.
Finally the last type of gas being a beer gas or a blended gas, is a mix of CO2 and Nitrogen, which we mentioned earlier. Typically about 75% carbon dioxide and 25% nitrogen, that percentage can range upward or downward a little bit just depending on where you get it or what you ask for. Some places will blend for you, others just have a standard blend that they use, 70, 30, 75, 25, 80, 20. Really just depends on where you go to get your gas.
As mentioned earlier, the most common use of beer gas is to allow you to have your draught system at a higher pressure for both running beverages over a longer distance and for serving under higher pressure without causing over combination.
A couple of things we should mention before we end this episode; there are a couple components that could be added into your gas system. One of which is a gas blender. Gas blenders basically take pure CO2 and pure Nitrogen and blend them into a specified ratio that you set within the gas blender and release a blended gas out of a third line.
Another component that you could look into, and these are great for coffee shops who are serving draught coffee now, are nitrogen generators. Nitrogen generators basically just take the ambient air and produce highly purified Nitrogen. They can be used for your draught system. If you are one of those coffee shops who is running through nitrogen tank a week or a couple of Nitrogen tanks a week, a nitrogen generator is something that you might want to look into.
The final component that you might want to look into is gas filter. This basically goes in line for your gas coming out of the tank and helps purify the gas further than it already may be purified. Depending on where you pick up your gas, they should be able to tell you the purity level. I believe food grade purity for carbon dioxide is considered 99.9% minimum. 99.9% or better would be food grade.
Purity levels are something that you can ask your gas supplier about, in fact, I just picked up a nitrogen tank today and started talking with the rep about purity levels. He told me that the nitrogen that I was getting was, what he called 395 pure, which means it was 99.9995% pure. Did I catch a nine in there? In fact I’m going to go use some of that nitrogen right now, pour myself a coffee and hit the road.
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Thanks for joining us today. We look forward to seeing you next Friday on the Drips & Draughts podcast.