Question about pasteurization

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codyw

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Ok, I am new to world of brewing and am just doing some hard research on the details of brewing before I start my first brew. Researching has gotten me thinking...

I know that most macro brew kegs are not pasteurized and therefore need to be refrigerated because room temperature will cause the bacteria to thrive. What I find odd is that microbrewing insists on long term conditioning of beers at room temperatures. We want the beer to be at room temp so the yeast can properly function, but what does this do in terms of bacteria?

Also, with macro brews, it seems they go bad after 120 days, but apparently waiting that long for a micro could be a good thing? Is it that the macros have already been sitting around that long to condition before they are sent out, then given the 120 day life?

I know this question is not very practical because as a micro brewer, one would not worry about the pasteurization, but I am just curious why there is a discrepancy between macro and micro when it comes to keeping non pasteurized beer at room temperatures.
 
Macro has taught the masses that fresher is better therfore they need to consume more, faster.

Micro is created to let the flavors develop. Unlike Macro that prides itself on being flavorless.
 
micros and especially homebrewers are a ton better at sanitation. a keg of micro at a bar might last a couple weeks. the BMC in the same bar lasts one to two days. BMC has their kegs in that bar not much more than a month after brew day, so a little wild yeast/bacteria never has a chance to do any damage. We take our time and work hard to make beer that gets better and better over time. So, frankly, we're better at making complex brews that not only stand the test of time, but get better and better as time goes on.BMC is great at doing things as quickly as possible, but notoriously bad at making complex beer. Have you tried any of michelob's "craft" brews? They're some of the worst beers I've ever tortured my tastebuds with.
 
If you are very sanitary in your practices then bacteria will not be able to get into and live in your beer. I thought all macro brewers pasteurized/filtered their beer at some point in the process just to be safe but if not I haven't heard of that.
 
shafferpilot,

you might have the answer I am looking for. If macro breweries are sloppy with sanitation, then it makes sense why their unpasteurized beer will spoil soon. Here is my only question then: If micro's are really about aging, then why will a kegged micro only last 2 weeks at a bar? It seems like people on this forum talk about leaving their beer kegged for months. Does it have to do with those 2 weeks being at serving temperature? I would think that would help it be unspoiled though?
Thanks guys
 
I just thought about it some more and concluded that it most likely only lasts two weeks after its been tapped and is exposed to oxygen. Thats it isnt it? Ahh the slow process of learning about brewing:)
 
I never have thought of the BMC as sloppy. They have no need to be sloppy, they have money, employees and equipment. They have QC departments and labs. My assumption is they are very clean.
 
codyw said:
I just thought about it some more and concluded that it most likely only lasts two weeks after its been tapped and is exposed to oxygen. Thats it isnt it? Ahh the slow process of learning about brewing:)

Tapping a keg does not expose it to oxygen. Unless of course you are using a party tap. Most kegs are pressurized with CO2.


+1 Brewpaster
 
CodyW,

I think you last point is accurate...there definelty a differnece between how long a beer can be stored in a keg vs. how long it can be stored once it has already been tapped once (I.E. the Oxygen Exposure)
 
My uncle had a keg of Bud around all the time. It was kept cold and under pressure. And It always tased the same to me, even when it was a couple months old.

The aging of beer is done mostly with stronger beers, barley wines, triples, imperial stouts and the like. They have lots of alcohol and often lots of hops and aging rounds and mellow thems. Lots of other beers really don't get better with age. Most beer is like bread - consume it while it is fresh. That is why brewpubs and local micros are so great - fresh beer. And homebrew is the freshest!

But aging is not for every beer.
 
Padstack31 said:
I still think some oxygen gets in and that it is not all just CO2 but hell, I could be wrong

If you're using CO2 to dispense the beer...yes you're wrong.

CO2 is PURE CO2, and CO2 does not oxidize beer like the regular air we breathe.

I've never heard of a micro brew only lasting two weeks in the keg at a bar, unless it is EMPTY after two weeks.

I'm the only person who drinks beer at my house, and i rarely have guests, so it takes me a month to drink 5 gallons...and I keep 3 kegs on tap, plus a few cases of bottled batches.

my beer is not skunked, soured, or past its expiration date.


If you're using any kind of hand pump to dispense the beer...yeah, you oxidize the crap out of it and better drink it in a weekend, or it'll taste stale next weekend no matter how cold you keep the keg.
 
brewpastor,

Like you say, it seems to make sense that a macro brewery is going to have great sanitation...

Ok, so what sort of consensus is there? Can we conclude the following?:

1) A keg of unpasteurized beer (micro or macro) that has not been exposed to oxygen/bacteria can be kept at room temperature for a long period of time without trouble

2) Once tapped, a beer should last a long time, as long as there are no leaks in the system to somehow allow some sort of oxygen exposure, and keeping it cool will help dwindle any sort or oxygen/bacteria exposure

Would this be safe to say? Thanks guys
 
Maybe I shouldn't go there, but it sounds to me like you're asking a question hidden behind a couple theorhetical questions. Are you thinking about getting into kegging but don't want to start with a fridge? It's a pretty common question but I never quite seen it asked this way.
 
it sounds like you have a keg out in a shed and want to know if it will poison you to me, but that is only because that is the kind of thing I would have done before I was legal
 
I've tasted a LOT of lagers that were skunked or wet cardboard tasting. Most had no freshness dating on them, but I'm pretty sure they sat on the unrefrigerated shelves for many months or years before I picked them up. Most were in brown bottles, too.

I haven't really tasted this problem with any ale....the worst off-flavors I've tasted in old 5% or under ales is a metallic twang....
 
beer kegs only last a few weeks in a bar, because the bar has poor sanitation procedures. There might not be oxygen in the CO2 system, but there's definitely all kinds of nasty stuff on the disconnect, the ball valve, the lines running up to the dispensing tower, the nozzles, etc.

My comments on BMC related simply to the speed at which the brew goes from brew day to consumption. And a sealed keg that's been sitting around definitely has the chance of getting nasty. I've had a few that were bad right from the first pint. Perhaps the problem with a big brewery storing beer for a long time is related to the pastuerization process? Kind of like how oxidation get's mroe and more noticeable over time?
 
hey guys im not trying to have a fridge-less keg, i am going to stick with bottles. I am just curious about the science behind how some beers spoil and others dont when warm in a given amount of time. Your insights have been helpful
 
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