From the time I started drinking beer until the time I got into the craft beer industry myself, I basically avoided drinking draft beer as much as I could, and stuck to bottles. Because draft beer almost always tasted totally gross.
I’ve since learned that the reason for this is that, as far as I can taste, almost all the draft beer lines in most American cities are not clean. And when I say they are not clean, I mean they are chock full of nasty shit, like this.
I found this line a while back at a very good restaurant where I was helping them do a little work on their system. They had put in all new draft lines only 9 months previously, but regular line cleaning at some point got lost during a management transition. So this buildup occurred in probably only about a few months of inadequate cleaning. When you think about how many draft lines in your town haven’t been cleaned in years (hint: probably a lot) you get a sense of what’s going into much of the beer being served near you.
(To be fair, of the eight lines I saw on this occasion, only this and one other line had this sort of buildup; two others had visible residue and four were visually mostly clean, although it’s hard to say for sure that nothing was going on inside them.)
We replaced the line shown here, of course, and then the beer on that tap tasted great. I’m confident that this restaurant will stay on top of it, now that they’ve seen both sides of the possibilities.
If you pour beers off a draft system, I hope this is helpful! It’s fairly easy to buy a line cleaning canister and line cleaner (we use PBW that costs about $25 for 4 pounds), and to clean each line at a keg change or every week or two. We’ve also found it good to do a deep clean (overnight soak) of each line periodically, and to change the lines out fully after some number of months (the industry recommendation I’ve heard is every six months). It’s a little extra time and expense, but isn’t great beer worth it?