5

I know how to tap beer from a keg with CO2. The CO2 provides the pressure and you will get the beer.

But how can germans tap their beer without using CO2?

9

I've never seen any evidence that Germans use anything but CO2, so if you have a source that'd be cool. That said, for getting beer out of the cask/keg/barrel you generally have 3 options:

  1. Pressurized gas. As mentioned by the other answer this is most commonly CO2 since CO2 is produced by yeast, so if you sealed the container while yeast were still processing sugars and producing CO2, they would pressurize the container. Some brewers, especially home brewers, will pressurize their kegs through natural carbonation but most just push CO2 from a canister. BUT there's also "beer gas" which is a mix of Nitrogen and CO2, think Guinness or Boddingtons. This came into use to emulate the soft carbonation of cask/real ale/kellerbier, which leads to:

  2. Siphoning. A hand pump, or beer engine, uses a siphon to "pull" the beer out of the cask and up to the tap. The physics needs atmospheric pressure to be maintained inside the cask, so it's usually open to the air at the top. This required a fast turnaround on casks to prevent the beer from spoiling, which is one of the reasons cask/"real" ale fell out favor. Kegs simply kept longer and were more economical. I think CAMRA still isn't a fan of them, but some bars use "breathers" which basically add very low pressures of CO2 to replace the volume lost by the beer, but not enough to pressurize the cask. This just lets the beer last longer in the cask.

  3. Gravity pouring. This tends to happen most often at festivals or if a bar has a "guest cask". A spout is installed in the side and beer pours out. All the caveats about air spoilage from cask ale still exist here.

So if the bartender pulls a handle and leaves it there until the glass is full of beer, that's a pressurized gas system. If the bartender has to keep pulling the handle to fill the glass and the beer has that cool "cascading" look, it was pulled by siphoning. If the cask is on the bar and the bartender just opens a spigot...that's a gravity pour.

I don't know that there are any other options...maybe an open barrel and ladling the beer out like soup?

  • ladling the beer out like soup I've seen it done with mead, but not beer. – Anthony Oct 7 '15 at 5:04
  • Actually, mix of nitrogen and CO2 is pretty common. Like, 70% of nitrogen. the point is, you don't want to change amount of dissolved carbon dioxide in any way, so mixtures are generally "safer" at serving pressure. For hi-carbonation beer, it will allow beer to lessen it's co2 content, but slowly. On low carbonated one, it will add co2 to it, but again - slow enough for it not to really matter. – Mołot Nov 11 '15 at 13:33
4

There is one new "sneaky" technique, where the beer is in a bag inside the keg. To create pressure, air is pumped into the area between the bag and the keg.

  • That's clever, do you know of any breweries using that? – Sloloem Sep 23 '15 at 16:05
  • South African Breweries. They use it for their 1895 beer in special locations – Atron Seige Sep 23 '15 at 16:07
2

There are two usual ways to extract beer from a barrel.

By gravity, one places a tap a short way up from the base and you allow air into the top. When you open the tap beer comes out. Generally you want to drink the beer quickly in this situation as it will go off. This method is commonly seen in beer exhibitions.

The other method is to use an overpressure of gas to push beer out. The gas can be CO2, Nitrogen or air. The pressure is usually generated by some form of pump. For Real Ale the handpump is the device of choice forcing air onto the beer and powered by human. In some places in Scotland the handpump is replaced by a water powered pump because Scots are engineers.

When the real ale resurrection happened in the 70s barmaids were actually warned to swap hands used to pull the pump lest they increase the muscles on one side and became lopsided as it were.

1

All beer has CO2 in it, whether or not its added artificially, even nitro pours. Not sure if you mean a gravity based pull system, or maybe a nitro tap line? Nitro beers use a gas mix of mostly nitrogen to some parts CO2 to give the beer a richer, creamier body and head.

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