Kompensatorzapfhahn/compensator tap

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Jul 4, 2014
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Does any one use a Kompensatorzapfhahn/compensator tap? It seems to be strictly a German thing. English would be beer engine. I want to know if it as simple as installing into any metal keg like any other bulkhead. I assume you don’t any kind of purge or vent because that that’s the job of the adjustment knob. I do not mind naturally carbonating it. It’s suppose to be able to keep the CO2 dissolved by maintain the pressure.



I’d like to try one, they make a corny adaptor too but I’m interested in the standard to install on any keg and letting gravity and pressure do the work.

I’ve only seen them on eBay.de and amazon.de
These are generically referred to as "flow control" faucets. There are a number of models made by other manufacturers including Perlick, the old/passed Vent Matic, the new-ish Intertap, and CM Becker (which look similar to the one shown), among a few others, and are quite popular among HBT members.

I don't think there's much bearing on that faucet (or any flow-control faucet) wrt "beer engine". That's actually a hand-operated pump, usually working in concert with a "cask breather" that allows uber-low pressure CO2 to back-fill the cask/keg to avoid oxidation without significantly increasing carbonation...


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These are generically referred to as "flow control" faucets
Thank you, I couldn’t find the English name, was working off braukaiser. I’m debating between the German faucet and the English engine system. Seems like people still use CO2 with the German system, I’m trying to avoid it.
It's a trade-off between the simplicity of the German system using conventional, relatively modern components, versus the "old school" English system, which one has to believe would be much more expensive to implement. And as cool as those beer engines look, realize they are massive. I've seen a few implementations here on HBT and the engines are total beasts :)

I brew and drink mostly English bitters and German lagers, so I have both an Angram beer engine and two Kompensatorzapfhahn (my other two taps are side-pull Czech lager taps, which are different again). As @day_trippr says, the beer engine and kompensatorzapfhahn are different and are usually used for very different beer styles.

The beer engine is designed for beers like real ale that have a very low carbonation levels (typically 1 to 1.5 vols of carbon dioxide). It is usually used to hand-pump beers up from casks in a cellar against gravity. The energy to move the beer comes from the person operating the pump. Since the cask head space is vented to the air or connected to a cask breather that supplies carbon dioxide at atmospheric pressure, there no gas pressure in the cask to deliver the beer. The swan neck in the picture above can be fitted with a sparker that causes some of the dissolved carbon dioxide to come out of solution and make a more creamy pint with a proper head*. Connecting any form of pressurized keg to a beer engine, either because the keg is pressurized, or because there is a lot of dissolved carbon dioxide in the beer, will cause a mess as the beer leaks out of the nozzle.

A kompensatorzapfhahn is designed for beers with higher carbonation levels, like lagers which may have 2.5 or more volumes of carbon dioxide dissolved in them. Typically the beer is pushed from the cellar to the tap by gas pressure from carbon dioxide connected to the keg in a properly balanced keg system. The gas pressure should be set to maintain the correct level of dissolved carbon dioxide at the serving temperature, and the trick to balancing is making sure that the pressure drop through the dispensing equipment is enough so that the beer comes out of the tap at a low enough pressure to prevent foaming. A typical kompensatorzapfhahn can give a pressure drop of up to 0.9 bar (13 psi) that can be used to balance a draft system for different serving pressures, and prevent foaming without changing the beer line length.

It sounds like you want to serve lagers with 2.5 volumes of carbon dioxide directly from a keg. You can do this with a kompensatorzapfhahn, but you'll need to bear two things in mind:
  1. Carbonating at 2.5 volumes requires 12 psi at a serving temperature of 40F. You can probably get a kompensatorzapfhahn to reduce the pressure sufficiently by cranking it all the way down, but the beer will trickle out.
  2. If you're not applying pressure to the keg as you drink the beer, the dissolved carbon dioxide will gradually come out of solution to equilibrate the pressure in the head space. This isn't a problem if you plan on drinking the whole keg in a night, but if you drink it over several days, the beer will become flat (or at least under carbonated for style).
The last time I was in Bavaria, I had beer served directly from a small barrel without any applied gas pressure. Pouring was a ritual, as you poured half a glass of beer, half a glass of foam, waited for the foam to settle and then topped off. The glasses they gave us were about 1/3 liter as trying to fill a liter glass as a pain. We finished the barrel in one night. (I actually suspect that there was a plastic bladder inside the barrel, as I didn't detect any oxygenation).

If your plan is to serve low carbonation ales from a cask (or keg), just let tap and spile the keg with the tap at the bottom of the barrel, and let gravity do the work of serving the beer.

* This is the right way to serve real ale and anyone who tells you otherwise is from the wrong part of the England... ;)
Thank so much @duncan.brown

You have both been super helpful.

What I’m trying to figure out what was going on historically. Between directly tapping a wooden barrel and modern CO2 system, the only thing in between seems to be that time period is the English engine. I wasn’t sure if there’s were any other techniques in Germany between wood barrel and CO2 pressurized cylinder.

Yes I was thinking did my doppelbock and other German styles I like to make. I would love to make an engine bitters. I feel cheating using a bladder not authentic considering how much time I put into having it follow the purity law.

Still find it a little hard to believe (just a little) that Germany when straight from wooden keg taps to pressurized air.
I asked my colleagues in Germany and here's what they said: the beer that I had from the barrel was from Bräustüberl Tegernsee and it was a helles. The beer was served by gravity from a wooden barrel with no plastic liner (I was wrong about that). Traditional barrels are lined with pitch (distilled tree resin) and modern beer barrels are lined with polyamide plastics. Take a look at Oak Beer Barrels at SASCHARUDNIK.com

The beer that they serve from wooden barrels has a lower carbonation level than the standard bottled or draft helles so it's easier to pour (and supposedly tastes smoother) but you still need to pour it carefully in two stages to manage the foam. The beer follows the Reinheitsgebot as the carbonation is from krausening.

The beer I had tasted great as the barrel was filled, freshly delivered from the local brewery, and drunk in less than 48 hours. Most of the brewery's beer is distributed in stainless-steel kegs and glass bottles. The wooden barrels we had are for special occasions, although it's not uncommon to be able to get beer from a wooden barrel from both local breweries and the bigger breweries in Bavaria. The German words to Google are "bier vom holzfass." (beer from a wooden barrel):

The English beer engine was developed for a completely different style of beer and, as I understand it, the beer engine is never used in Germany (outside English-style pubs). Germans went from "bier vom holzfass" to the modern draft system.

So it seems, if you want to be authentic with your German lagers: either gravity serve a naturally carbonated lager at 1.5 - 2 vols from a pitch-lined wooden barrel (and deal with the foam) or serve from a regular keg system. Save the beer engines for English beers.
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Sec. 5.6.1 of Kunze has this to say (paraphrasing slightly):

Wooden barrels have determined the transport of beer for centuries. Wooden barrels are lined with pitch (colophonium, paraffin, and resin oil) sprayed in at 180C and spread evenly over the interior of the barrel. The walls of wooden barrels are more than 3 cm thick to withstand the internal beer pressure and survive transport.

Kunze says that an empty 30 l barrel weighs 25 kg (about the same as the beer it can carry!) hence they are primarily of ceremonial use today. Most of the rest of the section discusses stainless-steel kegs...
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@ducan.brown Thank you so much, I’ve been scouring the interest to find what you just explained. I needed that inside source.

I’m doing mine with a kräusen but from what I’ve read, naturally carbonating larger vessels than bottle requires less (about half the amount). I can see now why the German handles have the forward and back function.

You answered the most important question in that Germany did not use engines. I completely forgot about pitch. They just build the a Hofbrauhaus in my city and are releasing their doppelbock tomorrow with a ceremony. Hopefully they will help me out too. Other than that it looks like I’m going to invest in a co2 system

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