I am still getting my head round keykegs. OK, I've examined them at close quarters at GBBF and understand how they work, but my question is about how they are filled and how the beer inside gets its CO2. Now a conventional keg, is filled upside down (usually) through its central extraction spear. Is it the same for a keykeg where the bag takes the place of the spear? Additionally since a keykeg is not subject to applied external CO2 being in contact with the beer and therefore does not "gain" CO2 from the dispense process, my assumption is that the volume of internal CO2 is set as (or before) it is filled and then it stays at that rate during dispense, as it is pushed out by the collapsing sphere. Is the beer pressure set at the filling unit? Can they be filled with beer set at whatever CO2 content the brewer needs? Essentially how is the internal CO2 pressure set? Anyone care to enlighten me?
Normally the volumes of CO2 is set in tank. That could be by secondary fermentation or by injection. I believe BrewDog, for instance, inject through a carbonation stone.
ReplyDeleteAs you know, the pressure and temperature can control carbonation rate very accurately.
Alternatively a carbonator, the same as is used for chill filtered beer in bottle, could be used at filling.
I believe that some brewers have tried to condition in keg, but this is not reliable.
Hope that helps.
Incidentally, I believe KeyKegs are a great idea. They can conform very well to the principles of "Real Ale" very well indeed.
ReplyDeleteIt is unfortunate that they have the dirty word "keg" in the name.
Classing it as a dirty word is akin to the "f" word being used as a name for love-making. When applied with tender care it can be beautiful.
As Dave said, the volume of CO2 in the beer is going to be determined in the tank prior to filling.
ReplyDeleteKey Kegs are filled upside down so as to not damage the bag.
Normal kegs are filled right side up through the spear...if you did it upside down that would be too much splashing. You could fill them upside down, but would be advised to fill through the gas port.
We all hate cask and keg washing, and managing our returnable assets, so single trip containers like this could obviousy have benefits, but that depends on what the outlets are doing with them after use. If they are recycled, then good. If not, less so. I see that Eurokeg claim 125% reduction in CO2 emissions which implies that they're somehow sucking greenhouse gases out of the atmosphere. Good trick.
ReplyDeleteI was under the impression there were subtle differences in the connector between the standard keykegs and what was deemed keycask for cask conditioning.
ReplyDeleteI also understand that there is a fundamental problem with "keycask" in that the collapsing of the bag disturbs the sediment of the beer so you do get excess ullage, variable depending on how the beer drops?
Incidentally @Dave, if "some brewers have tried" to condition in KeyCask (you imply many / most don't) how exactly do they "conform very well to the principles of 'Real Ale'"?
ReplyDeleteJust asking.
A lot of knowledge on KeyCasks here…. Indeed the volume of internal CO2 for precarbonized beer is set by the brewer and stays that way during dispense. The beer should not contain more than 5.0 gr CO2 per liter (2.5 volumes). KeyCask is already more environmental friendly even before it is recycled. On longer distances the amount of CO2 for example is 3-5 times less. Indeed one of breweries who tested KeyCasks experienced some unwished effects with the sendiment. We are looking into the possible causes and are confident it will be solved.
ReplyDeleteThe KeyKeg-team
I'm thinking it would be tough to conform to CAMRA policy on this one without turning the Key Keg into a giant snow globe...though I haven't tried it...
ReplyDeleteA wheat beer or lager with a dustier yeast would probably work better than a flocculant ale strain for key keg conditioning...if you accept non bright beer...
I was about to ask the same question on how you can cask-condition in these things without the sediment being disturbed every time the bag is compressed.
ReplyDeleteAn interesting feature of these is the way they do dispense. The air pushed into the ball does not touch the beer. In effect you can use a hand pump or CO2 to push the beer from the container.
ReplyDeleteparty pigs here in the states do an admirable job of not stirring up sediment when you dispense from them. At least that is my experience with home brew.
ReplyDeleteA handful of craft brewers use them.
http://www.partypig.com/