Ask a Cicerone Part 2: Off Flavors

We sat down with Andrew Kelley of Old Devil Moon for an ongoing conversation on all things beer; from the techniques of brewing specific types of beer all the way to proper tasting, and everything in between.
This week we jump right into a few of the most common off flavors that can be found in beer, what exactly causes them, and how to avoid them.

What separates a Cicerone from the everyday beer lover?

AK: A lot of consumers don't understand how important the bartender and the establishment are when it comes to buying beer. There are plenty of times where a customer will go to a place and order a draft beer that was brewed properly, but wasn't handled properly. 
Because they taste a beer that wasn't handled properly, they think the beer isn’t any good which reflects poorly on the brewer when it could’ve been the fact that the distributor left it on a hot truck for a day, you know, or the bar hadn't cleaned the draft lines, or something like that. 

We’ve heard that ODM sources from local breweries where you’ll have beer on tap within hours of them releasing it. 

AK: Yeah! You know that's one of the nice things about working directly with some small breweries. There are times where they'll tell me, “We're gonna have this beer in kegs tomorrow morning.” and we’ll have it within a couple hours of them filling those kegs. 

What goes into what you put on tap? Surely it's changing a lot. 

AK: Our individual beers rotate on a constant basis. Pre pandemic we had 20 handles, and each handle would change once every week or so. Now it's a little bit slower just because we don't have the volume to move that much in a given time, and we don’t want to serve beer that has been sitting on tap for a month.
95% of all beers are best fresh, so you don't want something sitting for a long time. There are tons of different off flavors that can be found in beers that have been handled improperly in that way.

What are some examples of those flavors?

One of the most widely recognized is skunking. Say you open a green bottle of beer from Europe and it smells a bit like skunk. That’s caused by light striking the oils in the beer and changing its chemical composition.
A lot of people think that European lagers are supposed to smell a bit skunky, but that flavor is actually caused by the green bottles they’re stored in. Green bottles don't reflect away nearly as much light as brown bottles, but because it’s part of their image at this point, all the breweries followed suit in Europe and now the European style light lagers tend to carry those off flavors, and people have gotten accustomed to them.

If green bottles aren’t the best way to store a beer, what is?

So green bottles block out something like thirty to forty percent of light and brown bottles are closer to 95 percent, so they’re slightly better. At the end of the day, it comes down to how the bottles themselves are stored. I've seen beer in brown bottles that has been skunked sitting in the front row of a refrigerator display with bright fluorescent lights shining down on it for a long time, so keeping bottles away from bright sources of light is really important.
Ultimately, cans really let in no light, so there’s no debate that cans are the best way to store beer if we’re talking about maintaining quality. There’s some conversation about how much oxygen gets into cans, but that’s more based on the inconsistencies of can manufacturing which is a totally different conversation. 

What effect can oxygen have on a beer?

It can cause beer to get stale, which is due to hop degradation and gives off a kind of wet cardboard flavor. Temperature also has a strong influence on hop degradation as well. It’s another one of those things that people are used to tasting from having so many beers that haven’t been handled properly.

How are you supposed to avoid hop degradation?

It seems simple, but just keep your beer cold. If a beer is kegged or packaged properly, it shouldn’t come in contact with much oxygen anyway, so controlling temperature is really the best way to avoid hop degradation. The rate of degradation is exponentially faster at room temperature, and if it ever gets above room temperature it's even worse.
It happens a lot in storage rooms with something like an ice machine in them, which has a compressor that's running all the time, those compressors can heat up a room pretty significantly and if you're storing your beer in that room it’s going to degrade within a day or two. 

Are there any other storage techniques that help keep beer fresh?

AK: Draft lines are where a lot of off flavors can come from, whether it’s from flavor leaching or from bacteria that like to grow in the lines. Flavor leaching usually comes from lines that are over fifteen feet, and introduces 'plasticy' flavors.
If the lines themselves aren’t properly washed and sanitized regularly, that is usually when people start to really notice that the beer isn’t right. It's usually because there's an infection in the draft line. We clean our draft lines every two weeks with a special alkaline solution to make sure that doesn’t happen. The bacteria in draft lines isn’t usually dangerous, but definitely introduces undesirable flavors.

There’s a myriad of other off flavors that Cicerones look out for to make sure they’re serving the best beer, but these are the most common examples that we’ve all probably come across. So if you’re a restaurant/bar owner, or someone at home who wants to keep their beer from tasting like it’s been poured by Pepe Le Pew, just remember:

1. Make sure to keep you beer cold at all times

2. Store any bottles of beer away from bright light

3. Always keep draft lines clean and less than 15 feet long.


If you want to pick Andrew’s mind a little more on the topic of off flavors, visit Old Devil Moon at 3472 Mission street.

Next week, we’ll be diving into different styles of beer, how they’re brewed, and their rise to popularity. 

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