Shelf life vs. temperature

[janka]

Hi.

I'm having a hard time finding much information apart from hunches on how the storage temperature affects the shelf life of a tapped keg. I hope someone here can help.

We're about to build a new bar. We will be serving draft beer at at least two different temperatures: Approx. 40° F and approx. 50° F. The ones served at 50° will be stored at 50°. The beers will typically be micro brew/craft beer.

The question is: What will shelf life be if the kegs we serve at 40° are stored at 40° vs. stored at 50° and flash chilled?

I know there is no definite answer, it all depends... I'm just hoping to get an idea whether there is a significant amount of shelf life gained, or if our expected keg turnover rate is well within the 50° shelf life anyway.

Thanks,
Jan

[DCullender]

American keg beer is NOT pasturized, therefore will spoil rapidly if not kept below 40 degrees. My best suggestion is to contact the breweries of the brands you wish to serve. They should be able to tell you the optimum temps for their beers and the probable results of storage at 50 degrees.

Let us know what you learn, thanks.

[janka]

I often read that the beer will spoil rapidly above 40° - the question is how fast?

At the moment (we already have a bar) our tapped kegs (including US micros) are kept at room temperature, approx 70-75°, and we usually manage to sell the beer before it goes bad on us. If it does go bad, it is usually one to two weeks after tapping it.
So I can say that "rapidly" for 50° should be well above two weeks...

I must admit that I have not yet asked any US brewers. I guess I have a feeling they will just say "store it below 40°", but I probably should work on getting proved wrong there :-)

As it happens, I'm going to Washington, Baltimore, Philadelphia, NY in October: I've read that Church Key in DC serves draft at 50°, so I will pay them a visit. Do anyone know of any other places in the area?

Thanks,
Jan

[cubby_swans]

American keg beer is NOT pasturized, therefore will spoil rapidly if not kept below 40 degrees. My best suggestion is to contact the breweries of the brands you wish to serve. They should be able to tell you the optimum temps for their beers and the probable results of storage at 50 degrees.

Let us know what you learn, thanks.

Incorrect. The statement that unpasteurized beer WILL spoil rapidly if not kept below 40F is a myth. 99% of the craft beers you see sitting in bottles on shelves in stores are unpasteurized, stored at ROOM TEMPERATURE, and are not spoiled. I have had countless unpasteurized beers that have been stored at 60-65F for YEARS and were outstanding beers. Many craft beers age very well. I bought a bottle of Deschutes Black Butte XXIV that says that it will be best AFTER July, 2013. These beers are intended to be stored at 'cellar' temperatures, which is about 55F.


Beer shelf life is a matter of personal opinion, and differs from beer style to beer style and from beer to beer. Flavors and characteristics in beer change over time. The warmer a beer is stored, the faster it ages. Hop characteristics fade with aging, so the warmer an IPA is stored, the faster it will lose it's hoppiness. Coffee and Vanilla fade over time, so coffee or vanilla stouts will have less of these flavors in them over time. The booziness in a bourbon barrel aged beer will mellow out over time. Many people feel a beer like Goose Island Bourbon County Stout is best after at least a year or two of age on it. I just drank one that had been in my basement since Christmas of last year and it was outstanding.

That said, most beers will not be desirable to drink after a certain amount of time. But some can last decades. It is true that most beers are best served fresh. 6 months after packaging date is a pretty common 'best by' date put on packaging by many breweries. But they're certainly not going to spoil rapidly if not kept below 40F. That statement is ridiculous at best.

[janka]

Incorrect. The statement that unpasteurized beer WILL spoil rapidly if not kept below 40F is a myth.

All true!

And now, back on topic: What about tapped kegs? ;-)

Jan

[cubby_swans]

Tapped kegs, as long as they are tapped with co2, have the same shelf life as an untapped keg. It still will vary by beer and even then from person to person as to whether or not the beer still holds the qualities a person deems to be palatable. Some people feel a hoppy IPA is too old and has lost too much hop characteristic at 2 months old while the same person might enjoy a year old keg of xxxx Imperial Stout. 2 years ago we tapped a 1/4 barrel of Cantillon unblended lambic that was from 1994 or 1995, at a party I was at. It is not a pasteurized keg and it sat in the distributor's home basement since he got it (in 1994 or 1995). The beer was outstanding. We didn't finish it. It was untapped, and moved back to the hosts basement 1/2 full. It's still quite fine.

If I ran a bar I would try to turn over most beers within a month or 2 at most. If a keg lasted longer than that, I'd think I made a poor selection for my bar as product that sits in a business that doesn't sell is just taking up space. Wasted space is $$$ in business. However, I'd probably try to get a keg of Bourbon County Stout or KBS or some other difficult to acquire beer(s) and sit on them for 6 months so I could surprise my customers with a killer keg that they wouldn't be able to get anywhere else around town.

[pizza&beer]

I'm wondering if you can accomplish your goal through the use of refridgerated and unrefridgerated glassware? Store all the beer at 40 degrees, saves you the hassle of two seperate coolers, and pour the desired beer into a room temperature or cold glass. You'd have to experiment and see how much the beer warms up. At worst, you now have to drink some beers but it might be a simpler solution. Good luck, curious to see how things work out for you.

[janka]

Tapped kegs, as long as they are tapped with co2, have the same shelf life as an untapped keg.

Maybe in a perfect (sterile) world. But in this world there will always be a little dirt in the keg valve and a little bit in the coupler even if properly cleaned, the gas is not 100% pure even if food grade, a bit of oxygen will enter the keg when coupled etc. etc. All tiny things that will slightly increase the speed of the degeneration.

Jan

[janka]

I'm wondering if you can accomplish your goal through the use of refridgerated and unrefridgerated glassware?

Naa. That would be a mess. I don't think it would work (i.e. raise the temp. enough), and it would definitely be hard to control the temperature of the served beer depending on size and glass type.

Jan

[cubby_swans]

Maybe in a perfect (sterile) world. But in this world there will always be a little dirt in the keg valve and a little bit in the coupler even if properly cleaned, the gas is not 100% pure even if food grade, a bit of oxygen will enter the keg when coupled etc. etc. All tiny things that will slightly increase the speed of the degeneration.

Jan

Let me preface this by saying that I know lots of beer nerds who have had kegs tapped for a LONG time with no noticeable degradation to the beer.

Oxygen in a keg will do little if anything to a beer in a keg unless you are shaking up the keg every day. Co2 is denser than Oxygen. Any oxygen in the headspace will be 'floating' on top of Co2 in the headspace. Regardless, Oxygen will not enter the keg when coupled. There's a dip tube that goes to the bottom of the keg. The keg valve is 'exit' only. Anything in the keg valve, be it oxygen or dirt, is coming out as soon as you pour a beer. Any air CAN'T go down the dip tube. I don't think any 'dirt' in the keg valve or coupler will cause a contamination that would work it's way down the dip tube without it getting cleared out with a beer pour every now and then. The contents of the keg are not going to contaminated very readily when tapped, IMO. Even non 'food' grade co2 is something like 99.97% pure... there is more air/oxygen in a bottle of beer on the shelf than what you're pumping in from the co2 tank. And again, if oxygen is part of that mix, it will be floating on top of the co2 in the headspace.

I'm telling you we tapped a keg of Cantillon a couple years ago, finished 1/2 of it, and have poured a bit off of it recently. It's all good still. I would be more concerned with the style of beer and how it ages (or doesn't) than whether or not it will get infected or oxygenated. If I had room in my kegerator I wouldn't hesitate to leave a keg of an Imperial Stout tapped for a year, not that one would last that long for me.