Nitro Setup

>> Thursday, February 26, 2015

This first batch got a little over carb'd

Today I'm doing a little bit of an equipment write-up. I really like nitro beers and will often order a pint of Polygamy Porter or whatever else they might have on nitro when I go to The Bayou, my local favorite beer bar. There's just something about that creamy head and extra smooth mouthfeel that is really nice. Also, due to the reduced carbonation level, nitro beers tend to be less filling than traditional draft beer. As most of my friends will probably tell you, this post is long overdue. I've been promising them nitro beer on tap for a long time and it took me a while to work out the kinks, but I finally have a working setup.

I recently (five months ago is recent, right?) decided to move forward with my plans to have a nitro offering on tap. I had a stout faucet that I'd bought years ago, but until now I'd never gotten around to buying the rest of the equipment needed to complete my nitro setup. My original plan was pretty simple; get a spare tank, fill it with beergas (g-mix), and enjoy some nitro beers. Those plans ended up changing a bit along the way but I think I ended up with a pretty solid system.

The first thing I did was order a 40CF Nitrogen tank. I got mine from Scott R (a.k.a. ezryder) via Scott sells a variety of used tanks (CO2, O2, Nitrogen) all of which have current hydro stamps and are priced well below anything I could find locally. Scott was great to work with and shipped the tank before he'd even received my payment. I'd definitely order from Scott again. To contact Scott directly, email him at and remove the "nospam_" portion.

With tank in hand, I headed to my local Airgas store to get it filled with beergas. This is when I ran into my first hurdle. I had anticipated having to leave my tank since most gas suppliers won't fill beergas tanks on demand. The Airgas guys were very helpful but unfortunately they had to break the bad news to me; they wouldn't be able to fill my 40CF tank. I'd asked about beergas a while back (at least a year or two ago) and they said they could do it, but I neglected to ask if there were special conditions/requirements. In this case they indicated they were only able to fill the larger cylinders common in the restaurant/bar industry (120CF??). They were however willing to trade me straight across for either a 60CF tank of pure nitrogen or a 60CF 60% N2 / 40% CO2 gas blend. I knew the 60/40 blends weren't recommended for nitro beers as they tended to over carbonate the beer. The other option of using straight Nitrogen was less than ideal because of the opposite issue...under-carbonated flat beer as you progress through the keg. So I had to figure out a plan B.

It just so happened that I'd been looking at some gas blenders on ebay. Gas blenders mix gas on the fly which means you hook up a CO2 tank and a Nitrogen tank to the blender and out comes the perfect blend for serving nitro beers. The pro's are nitrogen and CO2 are cheaper to purchase separately than in a blend, and the blenders are designed to provide the ideal ratio for nitrogen beers. The con is these things are freaking expensive...usually anywhere from $600 to $1200 for the cheaper models.  Sometimes you can find really good deals on used ones, which is what I was counting on for my plan B. So I decided to take the Airgas guys up on their offer to trade tanks and crossed my fingers in hopes of getting my hands on an affordable blender.

As I mentioned, I'd seen a couple used blenders on ebay. After missing out on the first one (Trumix TM100) I managed to win a Micromatic MM200. This blender is able to dispense two different blends, one for Nitro beers and one for non-Nitro Ales/Lagers. The ratios for each are Nitro = 75% N2 / 25% CO2 and Ales/Lagers = 30% N2 / 70% CO2. The Ale/Lager blend is really intended for long draw systems to keep from over carbonating the beer. That isn't a concern on my setup so I won't be using the Ale/Lager blend at all.

So now I had my stout faucet, my original CO2 tank, my 60CF Nitrogen tank, and my MM200 gas blender. I still needed a Nitrogen regulator and a couple secondary regulators. The secondary regulators are needed because the blender requires relatively high pressures, so one is used to reduce the pressure of the CO2 going to my non-nitro beer, and the other is used to step down the pressure ofmthe CO2/N2 blend for the nitro tap. I was lucky to find some regulators at a local store that deals in surplus and salvaged equipment (e.g. freight damaged goods). The secondary regulators were both brand new in box model 8011's from Micromatic. The price seemed great at $30 each. This is where I ran into another hurdle. I hooked everything up only to find one of the regulators was defective. After a lot of time spent troubleshooting, I took the defective regulator back and exchanged it for another one. This one also turned out to be defective (safety valve leaked). I headed back to the store to exchange it again and this time I got a good one. On the plus side, everything in the store was on sale for 50% off, so they refunded me $15 on the exchange.

Next up I pressure tested the whole system and this is when I ran into my last hurdle. The mixer and all the tubing connecting the various components tested fine, but as soon as I connected the keg, it would bleed down to about 20PSI overnight. The nitro beers are typically dispensed between 35 and 45 PSI, so this was definitely a problem; bad pours plus gas leaking to the atmosphere. The challenge with this kind of leak is it's so slow it's really hard to detect. Adventures in Homebrewing came to the rescue in the form of a sale...brand new ball lock kegs for $75. That wasn't far off from the going rate on used kegs, and I'd really wanted to get a few more kegs ever since upgrading my keezer from three to five taps, so I went ahead and pulled the trigger on a couple.  With a new keg in hand, I used a jumper to transfer from the old keg to the new one and thankfully it held pressure just fine.

To sum things up, I ended up spending a bit more than I'd originally planned, but I ended up with a pretty nice nitro setup. I may not always have a nitro beer on tap, but I'll probably have one in the regular rotation. I'm looking forward to trying out beers besides stouts on English Bitter...perhaps an IPA. Anyway, here are a few pics of the various components and how I put things together.

First up below is the stout faucet. As you can see, it's much more...stout :) than the regular faucet. Something to consider when building a coffin for your keezer and you want to make sure you have enough room to pour.

Next up is the gas mixer. There's a nitrogen in port and a CO2 in port. If either gas runs out, the unit shuts off the flow of the blend. The tee on the CO2 in runs a line over to the CO2 secondary for dispensing non-nitro beers. I tend to run mine around 12 PSI.

The last pic shows the secondary regulators mounted on the board to the left of the mixer. I'm currently serving nitro beers at about 40 PSI. You do have to carb the beer to a little over one volume before dispensing on nitro. This first keg got a little over carb'd, so the first couple pours were a little too foamy. They eventually settled down to the nice dense creamy head associated with nitro beers, but it took a minute or two.

Stout faucet compared to regular faucet
The gas mixer
Secondary regulators


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