In the old days, not the long-gone old days, but the recent old days, when craft brewing was new, I made an interesting discovery. I noticed that when I visited Seattle and sampled Oregon craft beers on draft, they didn’t seem to taste as good. I concluded that they did not travel well, hence the taste difference.
Later that year, I wandered up to British Columbia and visited the Granville Island Brewing Co. in Vancouver. I knew the brewmaster there at that time and was given a good tour of the premises, along with a sampling of its brews. It had been a good morning. That afternoon, I was tasting various Canadian brews at a local beer emporium when I noticed that the Granville Island beers on tap tasted odd. Since I had savored those same brews at the brewery that morning, I was stunned at how bad they tasted. Then I remembered that particular taste was due to dirty draft lines. In this case it was exceptionally noticeable.
I originally identified this particular taste in Everett, WA, where I grew up. I was drinking with an older friend, a former brewery employee, when he noticed that same phenomenon with a beer we were drinking. He identified this taste parameter to me so I could distinguish it. Later I found out that Everett was notorious in this regard in 1951 and Seattle not much better. I thought nothing more about the matter until that day in Canada when I remembered the very recognizable taste of dirty draft-beer lines.
As it happened, two Granville Island marketing people were seated near me. I stepped over and asked them to try their brewery’s beer and tell me what they thought. They knew something was wrong immediately, but not the reason until I explained it to them. The telltale taste that cruddy draft lines leave in beer is readily recognizable once you have been attuned to it. On my way back down to Portland, I stopped in Seattle and sampled the Oregon brews just to be sure, and there it was, dirty-line syndrome, as I call it. The Seattle brews had the same taste, but I had never tasted them any other way and had thought that was how they were supposed to taste. At that time Portland had a law that the tavern keeper had to clean his lines at least every two weeks, which is why I had never encountered that taste in my home city.
I can’t name the exact culprit in this scenario, but I know it when I taste it, and you would, too, if it were pointed out. I’ve not found anyone in the industry who can dignify that ester with a scientific designation. In any case, the moral here is double: Bar owners should clean their taps regularly and religiously (once a week is not too often), and brewers should sample their brews in as many venues as possible to ensure consistency of taste.