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Open Mate, Beta 2


Two long weeks ago, we finally scrounged the equipment and ingredients necessary to iterate Hack Pittsburgh’s Open Mate recipe. Personally, I hadn’t heard of this odd Club Mate beverage until I saw the recipe, but — being a homebrewer — I couldn’t help but to order a case (for comparison purposes only, of course) and hunt down some yerba matĂ© and caffeine powder of my own.

With said ingredients in hand, we put three gallons of water on the hot plate during one of our Tuesday open nights (come visit!), and proceeded to spend three hours hovering around the kitchen area, waiting for it to get anywhere near boiling. The tea was brewed, sugared, cooled, and kegged with the following specifications:


  • 3 gallons of water
  • 3oz yerba mate tea
  • 2c sugar
  • juice of 0.5 lemons
  • 0.5t citric acid



  • bring water to just under a boil
  • add tea to water (I put the tea in a big homebrewing grain bag, effectively creating a huge teabag)
  • steep for six minutes
  • remove tea
  • add sugar, lemon juice, citric acid
  • cool, pour into a keg, carbonate at 20psi

You’ll notice we skipped the caffeine this time. Personally, I’m more concerned with flavor than (added) stimulants, so I never bothered tracking down a scale sensitive enough to measure out one or two grams of powder. Feel free to add that in when you’re adding the sugar (check out Hack Pittsburgh’s recipe for the correct measurements and warnings).

Good Head, Dirty Fingernails


We finally got to do some beta tasting this past Thursday, and all testers agreed that it was yummy and pretty faithful to the original product. I have since sat down for a more in-depth side-by-side comparison (not double-blinded, mind you), and I feel our recipe — although quite tasty — has come up a bit short compared to the real deal. The sweetness is spot on, but there is a complexity and depth to the tea flavor that is missing in our beverage. So I think we’ll try some things differently next time:

  • adding lemon was a mistake: I was hoping to avoid uncommon ingredients like citric acid, but alas, you should go out and get some (cream of tartar was a pretty popular substitute in old-timey ginger beer recipes)
  • more citric acid: fizzy tea is pretty dull without a bit of acid zing. We should probably at least double it next time, but further experimentation is in order
  • increase the tea input: I’m hoping part of the depth-of-flavor difference is merely a matter of strength
  • caramelize some of the sugar first: Club Mate has added coloring. Hopefully caramelizing some of the sugar will make Open Mate less pale, and also improve flavor.

Any other ideas? I can’t wait to work through our first three gallons, so we can start brewing the next version. Bottoms up!

Down the Hatch, Without a Scratch

from on April 17th, 2010Comments8 Comments

8 Comments on “Open Mate, Beta 2”

  1. 1 Awesome said at 1:33 pm on May 19th, 2010:

    This is awesome. May I ask what this kind of keg is called, and what equipment is needed for pressurizing drinks like this? And, is it stored in that keg until it’s empty, or is it possible to bottle this stuff? Also, how long can it stand without going bad?
    I love the original stuff, hope I can make some of my own soonish 🙂

  2. 2 cjp said at 3:53 pm on May 24th, 2010:

    The Yerba Mate alone should give enough color to the beverage.
    This may indicate you haven’t used enough. What was your source for the Yerba Mate, anyway?

  3. 3 berticus said at 10:55 am on June 13th, 2010:

    Whoops! Sorry your comments got stuck in moderation limbo for so long.

    @Awesome: most folks call these corny kegs, which is short for cornelius keg. They’re usually five gallons, but this one is only three gallons. They used to be used for soda, but nowadays pepsi and coke prefer to ship around concentrate and add water on site. Can’t say I blame them. You can get used five gallon corny kegs for twenty or thirty bucks on ebay. Used three gallon kegs are more expensive usually.

    To carbonate and dispense you’ll need a co2 cylinder, a pressure regulator, and the appropriate connectors. You can probably bottle it out of the keg, yes. People do that with beer quite often. You could even carbonate it “naturally” with yeast, but you’d have to make it in 2 liter plastic bottles and store it in the fridge after they ferment for a day or two.

    I’m not sure of the shelf life. It should last a while, as it stays under co2, so there’s no spoilage from air contact and contamination. We drink it within two or three weeks, so it’s a non-issue.

    @cjp: I got the yerba mate tea from Wegmans. I’m going to make another batch today… will probably double the tea amount… but I still don’t suspect it’ll reach the same color as the real thing. We’ll see.

  4. 4 Mike said at 1:35 pm on June 23rd, 2010:

    The type of keg is unknown but to pressurize you would use a standard CO2 tank with a regulator… both of which are not cheap. If you wish to bottle there are two ways to carbonate. the first is called priming sugar. this is a little bit finer then traditional sugar but not as fine as powdered sugar. The second is much simpler. All that is required are carbonation tablest. two tablets per bottle. if you are going to bottle you will need to make sure that you are making the bottle air tight some how. Us a glass bottle with a cork or a cap, but with the cap you will need a caper. All of these items can be found at a local home brew beer or wine shop.

  5. 5 Awesome said at 8:46 am on August 15th, 2010:

    Ah, thanks for clearing that up!

    Searching for a “corny keg” brings up proper results. Didn’t know about those carbonation tablets either.

    We’ll see…

  6. 6 Dan said at 10:47 am on November 2nd, 2010:

    The carbonation tabs are really nothing more than a pre-measured compact sugar cube for the existing yeast in a homebrewed beer to continue eating inside the bottle. This is called bottle conditioning and gives natural carbonation to the bottle since the escaping gas has nowhere to go but into the beer.

    Since this mate brew will have no yeast in it from a fermentation, you would need to add just enough for carbonation purposes and not a ton of alcohol production to the main batch after it has cooled. Mix it into the main batch and then bottle with a carb tab or “priming sugar”.

    Alternatively you could just add a small amount to each bottle if you were not bottling the whole batch.

    Check this site for some interesting related info. Going by his recommendation you would use about 1/2 teaspoon of yeast per gallon for a normal carbonation level:

  7. 7 Hacking Club-Mate | Jason Kumpf said at 9:46 pm on December 29th, 2011:

    […] of an open source recipe is that anyone can pick it up and brew their own batch. Interlockroc’s Open Mate spinoff experimented with adding some citrus juice, with (apparently) dubious […]

  8. 8 Club Mate en los hackerspaces | Stgo Maker Space said at 6:12 pm on May 22nd, 2014:

    […] Open Mate […]

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