While we are on the topic, why do some beer taste better on draught than it does in a bottle? There are two sides to this coin. Hard facts supported by science and the individual experience of enjoyment. Annoyingly, both are correct. As someone who interacts daily with customers buying package beer and/or drinking draught beer, I am constantly being told which packaging type is better for flavor. Since both the science and person opinion are correct, I will tackle the boring facts first.
Beer has many enemies; light, oxygen, heat, time & spoilage organisms are the most common. Cans are the best packaging form to protect beer flavor, because they eliminate both light and oxygen. It is impossible for a can of beer to become “Skunky”, because aluminum blocks all forms of Ultra Violet (UV) rays. UV rays found in both Sun light and florescent light will skunk a beer. Another name for this is “Light Struck”. Cans are also completely air tight, which ensure no oxygen can affect the beer’s flavor after it has been sealed at the brewery. I often hear customers remark that cans give off a metallic flavor in the beer. This is technically not true because beer cans are coated with a water based polymer lining on the inside which provides a barrier between the beer and the aluminum can. The primary flaw found in canned beer is one that is found in all types of packaging, improper storage. If you conducted a side by side comparison of an identical beer with the difference being, a year old can stored at room temperature versus a bottle that sat in a dark 38°F cooler, chances are the bottled beer will taste better. If both the can and bottle of the identical batch of beer were properly stored, you would not be able to tell the difference in a blind taste test.
Bottles have two primary flaws for protecting beer flavor from oxygen and light. Bottles are not as air tight as cans because the seal between the cap and the glass allows for small amounts of oxygen to seep into the beer over long periods of time. To give you a frame of reference, an open container of beer exposed to oxygen will go stale in less than 24 hours. Not to make this even more confusing, but all beer has oxygen suspended in the liquid. This is called dissolved oxygen (dO2). One of the reasons beer should always be kept cold is it slows the dO2’s ability to cause the beer to go stale. The best breweries take precautions to ensure they have the lowest amount of dO2 in their beer as possible. The second reason bottle beer is not as good at protecting beer flavor is all bottles allow some form of UV rays to penetrate the beer. As mentioned earlier, light causes skunky aroma in beer. Brown bottles are the best at blocking the harmful UV rays. They block 95% compared to 5% in green bottles and 0% in clear bottles. Back in the 70’s and 80’s the American public was tricked into thinking imported green bottled beer was of higher quality, and was referred to as “Premium”. Instead of higher quality, everyone who favored green bottles consumed skunky beer. To this day, most people attribute the skunky aroma in Heineken as intentional and even desired. Next time you look at a Sam Adam’s six pack on the shelf, notice how high the cardboard packaging is compared to almost anything else in the market.
The worst package form are kegs; however, they can be the best if a bar or restaurant knows what they are doing. Hint, 95% do not know what they are doing. Kegs are basically big cans with one difference, they are reusable and need to be properly cleaned and sanitized in between refilling. Generally, this is not a problem because breweries go to great lengths to protect their beer. Once a brewery ships their beer to a bar, they generally lose the ability to keep it protected. Kegs are supposed to be kept at 38 degrees when stored and served on draught. I have walked into restaurants and have seen full kegs in the bathroom hallway, sitting at room temperature (see below). Bars, Restaurants and bottle shops also need to ensure their draught lines are clean and sanitized regularly. This is often not the case. Beer also needs to be served in clean and proper glassware. Again, often not the case. Lastly, when you are shopping for a six pack of beer, you can always look for the packaging date. I don’t know of any establishment that advertises when their kegs on draught were packaged. If you go to a bar that doesn’t understand how to protect draught beer, you are better off ordering something in a can.
So, if all of this is true, why then do people believe some beer tastes better on draught than in a bottle, or that a bottle is better than a can? It all comes down to the experience you are having at the time you first tried that beer. Let’s say that you are at a bar with all your closest friends and are reminiscing about the good ole days. The bar is jumping, everyone is having a great time and you try a new beer on draught. It’s amazing, it’s hands down the best beer you have ever had. You then spend the next 4 months searching for this beer and finally find it on the shelf in a grocery store. You take it home and have it again for the first time, only this time it’s a letdown. In your mind, you immediately associate that this beer must be better on draught than at home in a can. Another one I hear often, “I was in Ireland and had a Guinness, it was amazing, but all Guinness that makes it to the States is horrible”. For most, visiting Ireland is a once in a life time trip. So, it’s no wonder that every pint of Guinness from then on will fail to live up to your expectations.
There is clear science that proves cans are better at protecting beer flavor than bottles. But, if you believe that bottle beer tastes better than canned beer, you are not wrong. Flavor has as much to do with memories as it does with our taste buds. Drink what you like, in whatever packaging form you believe is best. Here are a couple pro-tips to ensure your beer tastes the way the brewery intended. If you have the option, buy less than 6-month old canned beer that was stored in a refrigerated cooler. If you like green bottled import lagers, opt for a brown bottled Pilsner Urquell. If you consider yourself an advanced beer drinker, buy Orval in a bottle, this Belgian Trappist beer gets better with age. Pair it with Stilton Blue Cheese from Southern Whey (you’re welcome). Lastly, drink draught beer at places that personally take care of their draught system (Triangle Wine Company, Southern Pines Growler Shop, breweries, etc.).