Updated: Mar 11
There are three things you can do to keep draft beer fresh: Manage the time in storage, track how long the keg is on tap, and maintain a good storage temperature.
Keg Punk is a centralized keg inventory and tap management system
Time in Storage
Almost any consumable product has an expiration date, regardless of how meticulously it was prepared and packaged. Kegged beer is no different. Assuming that your packaging techniques limit the introduction of oxygen and harmful micro-organisms, the beer in each keg will keep for some time, but will eventually degrade. The timeframe for this is dynamic and somewhat subjective.
From a widely known and respected homebrewer and author:
"Two common questions are, 'How long will a homebrewed beer keep?' and 'Will it spoil?' The answer is that homebrewed beer has a fairly long storage life. Depending on the style and original gravity, the beer will keep for more than a year."
Palmer, John. How to Brew. Brewers Publications, 2006. pg 114
From a common purveyor of commercial kegs and draft beer equipment:
"Pasteurized beers can stay fresh from three to six months. For non-pasteurized beers, you can expect the keg to stay fresh approximately two months."
“How Long Does A Keg Stay Fresh? | BeverageFactory.Com.” Beverage Factory, www.beveragefactory.com/blog/draft-beer/how-long-does-a-keg-stay-fresh/#:%7E:text=For%20a%20properly%20stored%20keg,stay%20fresh%20approximately%20two%20months. Accessed 26 Jan. 2022.
The great thing about brewing and serving your own beer is that YOU have the deciding vote when it comes to what's fresh and what's not. Set your own standards. This may vary based on the styles you brew, your equipment, or just personal preference. There are tools available to help you manage and track the storage time of your kegs. This is especially useful if, for example, you are a brewery owner and you need to keep your staff informed on what kegs are within your standard for storage time.
Time On Tap
Once you tap a keg and apply pressure to serve, the clock starts ticking a little faster. By tapping the keg, you've effectively taken a closed container and "opened" it to pressure changes, foreign gasses (i.e. - serving CO2), and possibly infection if sanitation is neglected.
From Draft Beer Quality Manual 2019
"Beer flavor in kegs that have been on tap for longer than 45 days may have changed compared to the intended flavor."
Technical Committee of the Brewers Association. Draught Beer Quality Manual. 4th ed., Brewers Publications, 2019.
Craft breweries often entice patrons with claims of "fresh beer" (as apposed to beer that has gone through careless shipping and lots of shelf time). Being able to tell a patron that you just tapped the keg yesterday gives them a sense of assurance and exclusivity.
Tracking "On Tap" time for each keg could be difficult if you have anything more than a few taps and multiple people tending them. Consider using software to help with this.
Maintaining a consistent storage temperature gives your beer the best chance at a great pour. Too high and you run the risk of spoilage, too low and carbonation will be affected.
Temperature Too Low
"Lower temperatures will cause the beer to retain its carbonation, preventing you from experiencing the nuanced flavors and aromas of each pour. If you allow the temperature to drop even further, below 28 degrees Fahrenheit, your beer is likely to freeze."
Temperature Too High
"Keeping a keg at a higher temperature will not only cause your beer to excessively foam but it will also lead to stale beer. Temperatures above 55 degrees Fahrenheit will likely cause your beer to grow bacteria and increase your chances of premature spoilage."
How Long Does A Keg Stay Fresh? | BeverageFactory.Com.” Beverage Factory, www.beveragefactory.com/blog/draft-beer/how-long-does-a-keg-stay-fresh/#:%7E:text=For%20a%20properly%20stored%20keg,stay%20fresh%20approximately%20two%20months. Accessed 26 Jan. 2022.
Time and temperature are the key factors in maintaining freshness with your draft beer. Tracking storage and on tap time of individual kegs is easily done with the right software. While managing storage and serving temperatures is as easy as setting the cooler thermostat.