I wouldn’t call the discussion around 0 IBU beers to be controversial so much as it is confused. I suspect a lot of the confusion comes from a misunderstanding of the relationship between IBUs, perceived bitterness and the different ways that bitter flavours can be introduced in beer.
IBUs (International Bitterness Units) are a measurement of the main source of bitterness in beer, isomerised alpha acids. I hesitate to use the word measurement, as most brewers are not using spectrophotometry to analyse their beers. Instead, by applying one of three different formulas to their ingredients and brew methods to come up with an approximation. So right off the bat, IBU is an imprecise indicator at best.
Adding to the confusion is the fact that the IBUs on the label of a beer does not have a direct relationship with how bitter that beer will taste. This is because bitterness can be influenced not just by isomerised alpha acids, but also by beta acids. This is a more complex relationship, because beta acids don’t add bitterness until oxidation begins, and that process also removes bitterness provided by alpha acids, normally causing a net loss of bitterness. Finally, bitterness can also be added roasted malts, as I went over a bit in this post.
Still with me? Great, so lets mess it up a little more by adding in that, regardless of the source, bitter flavours are offset by sweetness. In other words, the sweeter the beer, the lower the apparent bitterness, and vice versa.
So, now that you’re wondering why anyone would even bother putting IBUs on a package, what’s the significance of a 0 IBU beer? This gets pretty subjective. I’ve run across interviews with a few brewers who’ve made this style of beer, and the general attitude is one of exploration of brewing concepts. If you’re an experimental sort of brewer, the idea of a beer that has the aroma and flavour profiles of an IPA, but with very low bitterness, is a very interesting one. Considering the success of the incredibly juicy NEIPAs of late, and their low perceived bitterness, its not that extreme an idea either.
Locally, we’ve already seen 0 IBU IPAs from Twin Sails and Powell Brewing, and probably a few others. The other night, I got a chance to try Red Collar Brewing‘s Rocket Dog Dark Session IPA, the latest local example of this style.
This beer poured a very deep amber, with an off-white head. It had aromas I would expect out of a session IPA brewed on the West Coast — toffee, bread crust, earthy herbal notes, and grapefruit pith. Flavour wise, there was some toffee sweetness and bread crust, light bitterness, with a herbal and resinous finish. With a low to medium body, and mild carbonation, it would be easy to accidentally knock back a four pack in a sitting.
For a food pairing, I recommend trying the meal you can see being prepared in the background of my photos above, a warm roast vegetable and couscous salad.