unrefrigerated keg life, southern France
A bit of background:
We are in the south of France & sell only kegs. There is no cold storage, it gets hot down here and this is the situation it will not change. All the big boys can stock outside in the sun! I hear that they are sterile filtering now. They put 14 months on the expiration date.
Since my brewer quit, for now, I do it all with the help of a brewer over the phone. I'm really just a mechanic but I built this joint & now I'm attacking my core problem - spoiling beer.
I finish with .45 certified sterile cartridge - Is the beer coming out of this filter really completly sterile at this point? Does sterile really equal stable or could sugar, oxygen or something else allow it to go off, really off really fast.
So what about my first question? I'll ask about the next obvious process next.
Two things I would check first.
Are your sterile filters intact? It takes just a small defect or rupture and they are useless.
Second, Are your kegs clean and sterile before filling? 120+ degree steam.
If the above is correct, you should have no problems, but I am not sure about 14 months.
Also, I would at least try to keep them out of direct sunlight.
Hope this helps.
Here in Australia it is very hot and no refrigeration is the norm.... However we put 3 months on kegs; I would be reluctant to put 14 months on any beer.
I would start back in your process and make sure everything is right back at fermentation. Make sure your beers are hitting their attenuation limit (fermenting out all the way) to minimise residual fermentable sugar for any bacteria, check your sterile filters - and how you sterilise them!, check your keg cleaner, and check a keg.... and be sure you are filling clean (if filling manually it will be easy to infect things if the keg couplers are contaminated).
Sterile filter integrety
Thanks for the quick reply.
I contacted the manufacturer & they sent spec sheets about testing with micro bubbles. I really need to be able to verify filter integrity.
Do you know a simple test?
I sterilize with water that starts out boiling in the hot liquer tank 104c & it comes out the discharge at 80c + but I would love to get a steam generator. I do about 140 kegs x 30l in a run which takes about 50 hectoliters of boiling water & about 124 kilos of propane. I imagine a steam generator would cost less in energy.
I am curious to hear others' experiences with distributing kegs that will be kept at room temperature and served through flash chillers. Where I am, no refrigeration is also the norm and this is an issue I have been struggling with in my planning stages. Is a sterile filter a MUST in this situation? If your production process, filtration and packaging are all sound what kind of lifespan can you expect from an untapped keg sitting at room temps averaging 80 degrees? what about after tapping the keg?
Last edited by dfalken; 10-19-2011 at 05:23 AM.
sterile and absolute
Not only must the beer & the keg and everything between it & filter be absolutely sterile but watch out what happens ar +30c with normal carbonization. You need 1 bar at 10c & 3 bar at 30c & it will shoot out of the tap at 50 kilometers an hour. You lower the co˛ & use tetra hops.
If its not sterile give it about 4 or 5 days & dump it.
I am afraid, the bubble test is the only way to test the intrigrity of the filters.
(That I know of at this time)
Hot water is ok, but as mentioned before, sterile takes temp. well above 100 degrees C.
Other options other than Sterile filtration is flash pasteurising and refrigeration. You may want to reconsider on this. It is better then dumping beer down the drain.
Shelf life? Even optimal conditions and lower ambient temperatures then yours, I still only would like 3 months on a keg. I am sure it would last longer, but why have kegs sitting around for over 3 months.
hope this helps