Thursday, March 6, 2014

Common Off-Flavors In Homebrew - Part 2: Hoppy Beers Brewed with Unfiltered (Chlorinated) Water

In Part 1 of my riveting new blog series, I addressed the scapegoat of so many bad beers: vague, unspecified infections. Basically, I think it's great that homebrewers are as paranoid about proper sanitation as they are, because it's so easy to be these days. It's so easy that I don't think infections are actually super frequent (though please do share your experiences back in that entry.) Nonetheless, you, or someone you know, will soon taste a beer that tastes like rubber or Band-Aids. Off-flavors are rampant — and infections usually aren't responsible, despite (or perhaps because of) brewers' great paranoia of them.

So what are the off-flavors you are most likely to encounter? In this series of blog posts, "Common Off-Flavors In Homebrew," I'm not going to look at the specific chemical off-flavors themselves (for which there are already countless solid guides online) but rather the situations and contexts that most often lead to off-flavors. In the last few years, in beers from a number of states and brewers (including my own), I've encountered enough repetitions of certain off-flavors that I'm beginning to notice some patterns.

This occasional, 'as-I-think-of-them' series will address some of the most commonly-occurring situations (in my opinion) in which off-flavors are likely to arise in homebrew.

Situation 1: Hoppy Beers Brewed with Unfiltered (Chlorinated) Water
Unfiltered water seems to be an issue for brewers everywhere. Water is hugely important in brewing for a number of reasons, and can lead to off-flavors through an out-of-wack mash PH or excessively high mineral levels. But even before that — without getting into any complicated chemistry — there's something big to watch out for. If you're getting your water from a municipal water source, you probably have moderate to high levels of chlorine in your water. Hard or soft, municipal or well, we often overlook the simple fact that much of the water we drink is treated with chemicals specifically designed to thwart micro-organisms. Swimming pools are not synonymous with tasting good, and that's not just because of all the surprise urine lurking in them.

So while there's probably a number of ways that unfiltered water can react with the brewing process negatively, it seems to jump out at me especially, aggressively, when I'm drinking an IPA brewed by someone that uses tap water but doesn't treat it or filter it in any way. Chemistry is my weak spot, but I've had enough experience with this combination that I'm ready to step up and point a finger.

A couple years ago when I first moved to my current town, I brewed a Rakau single-hop pale ale that tasted very odd. The flavor profile (of what was meant to be a simple, pale, fruity beer) was utterly perplexing. In the original write-up, I described the character as "Belgian-like," with spicy, grassy notes more like a saison than an American pale ale. Phenols everywhere, and from an English yeast strain that I had just used in other beers with standard results. Unexpected, certainly. The hop flavor was almost entirely washed out by this harsh character, though it wasn't entirely undrinkable either. The problem was half mouthfeel, half flavor... and, intriguingly, never experienced again in my own brews after I started filtering my water with a carbon block filter.

I might not have given much thought to the issue if I didn't start encountering this exact same profile in many other homebrewer's beers. Same symptoms: same grassy, phenolic palate, same lingering spicy character verging on a stressed farmhouse ale. Every time the culprit beer is an ordinary pale ale or IPA. And every time, from a brewer that reported they did not filter their tap water in any way.

I'm sure chlorine — or whatever else it is lurking in unfiltered water — does its damage to styles outside of IPA too, but the combination of this harsh water in a hoppy beer seems the most egregious. At least, I'm particularly sensitive to it. And it's no fun, unless you want half your beers to taste like poorly-brewed saisons dry-hopped with sun-dried grass clippings.

Even if you don't want to think about residual alkalinity or deal with adjusting your water chemistry, please, filter your water, or brew with nice clean spring / RO water from the store. Crap from the tap leads to crap on tap.


  1. Do you have any idea what the concentration of chlorine is in your municipal tap water? I use unfiltered tap water (in London) and have never detected any off flavours as a result of it (although admittedly I've only been brewing just over a year).

    1. It's fairly high in my town, though I don't know the concentration. I've gotten this from beers brewed all over the place though, so it would be hard to gauge where the threshold is. And I certainly could be wrong about the issue being this simple, or I could be overlooking some other factors — it might be more than just chlorine at work.

      Still, for anyone that suspects their water may have some crap in it, I think a filter is an important investment. You don't have to worry about fluctuations in quality or a seasonal spike in chlorine.

    2. Former elected official who was serving during a big water purification debate here. Our MWS used chloramine, which can't be removed save for with reverse/osmosis systems - it ensured persistence of free chlorine in water at close to EPA standards (4 ppm). We actually shifted away from this at a significant cost to ratepayers and taxpayers due to the uncertainty surrounding the use of chloramines and we're transitioning towards a carbon filtration system.

      About 20% of the municipalities in America treat their water with free chlorine, typically around 4ppm. Another 60% use chloramine, due to the persistence benefits it presents - these municipalities are the ones where you either have to R/O filter your water, or use distilled/bottled water to brew with. The other 20% use combinations of alternative methods, including UV treatment and carbon filtration.

      The EPA has promulgated a bunch of new rules recently regarding drinking water treatment, so a lot of places are currently investigating their existing practices. Anything save for chloramine can be effectively removed from water to make it such that you can brew with it, so give your municipal water board a ring.

  2. In your experience, what are the disadvantages -- if any -- of using campden tablets to eliminate Chlorine and Chloramine while also treating tap water to reach appropriate and desired pH and mineral levels, rather than using filtered or spring/RO water?

  3. I've used campden tablets for years. It's super fast, effective and makes the water perfect for brewing (as long as you don't have other nasty stuff in your tap water.) As long as you are using city water, you are probably fine with just campden tablets. If you're on well water, get a filter!!


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