“It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness.…” To hear some folks tell it, a hazy beer is either emblematic of the state of the art of beer or a symbol of slipshod brewing. In all sincerity, they might both be right. Haze, in and of itself, is not something to be praised or condemned. It is desirable and helpful in a number of styles, but it can signal a serious problem that might warrant dumping the entire batch down the drain. Knowing when and how haze comes to be, can be created, and can be avoided might just keep your beer from landing on the wrong side of Dickens’s pairings. What a time to be a brewer—“It was the epoch of belief, it was the epoch of incredulity.”
Haze, For Better or Worse
At its most basic level, haze in beer is caused by the interruption of the passage of light through a beer by particulates that are in suspension in that beer. When the light is diffused or blocked, it appears as mistiness, fog, or murkiness, and as it intensifies, it might even render a beer thoroughly opaque. Where does it come from? Typically, we’re talking about one (or more) of three things: proteins, yeast, and polyphenols. Each is present in every beer (until and unless it’s been filtered)—it’s only a question of whether they’re present in sufficient quantity and density to cause a visible effect, and they might even be present with virtually no effect on flavor. Haze can also be caused by the presence of bacteria, though in that case there’s virtually no chance that there isn’t a noticeable flavor impact.
There are times when haze is simply a sign of a stylistically appropriate beer. The most obvious examples are beers characterized by their use of wheat. The presence of a significant dose of wheat in the grist imparts a higher-than-usual (relative to pure-barley beers) level of proteins in suspension in the finished beer. Wheat beers are also often fermented with very low-flocculating yeast and/or have yeast actually added to the beer or roused back up to accentuate their cloudy look. Maybe the brewers weren’t all that conscientious about using highly flocculent yeast in a beer that wasn’t crystal clear, but there’s no doubt that both proteins and yeast are commonly expected features in lots of wheat beers. Any beer that’s high in protein-heavy grains and/or is typically served young or with non-flocculent yeast is likely to be a bit on the hazy side.
Haze can also be an artifact of hops usage, and that doesn’t necessarily mean there’s a problematic excess of proteins or yeast. Hops impart polyphenols, which can be visible in beer and, given the right type and amount of hops (low alpha-acid and/or aromatic hops, and lots of them), might add a touch of haze to the beer. Hops polyphenols tend to be even more visible when they clump together with proteins from the grain. Why would they do that? Well, they get cold and huddle together for warmth. Okay, not really, but chilling beer does cause the proteins and polyphenols to cluster, adding what we’ve come to call “chill haze,” since the newly clumped particles are blocking more light when cold even though the beer may appear quite clear at room or cellar temperatures.
If you’re in that unlucky contingent, though, that is having haze trouble because of the presence of contaminating bacteria, you may be in for a rough ride. Bacteria, unlike yeast, are more persistent in solution and, therefore, add haze, and that’s before we get to the off-flavors they can impart, which include sharp sourness, sulfur, and fecal flavors, or (if you’re lucky) diacetyl or vegetal flavors. If you think a beer might be contaminated, its appearance may give you a secondary indicator to help you reach a conclusion (useful in diagnosing potential bottle bombs). To reiterate, though, haze is a symptom and not a disease in and of itself. Anything that blocks light from passing through the beer is causing haze, and sometimes those things are highly desirable or unavoidable.
Let us assume that you actually want haze in your beer—which is more than possible, given the theme of this issue! What options exist to proactively add haze in a way that doesn’t compromise the flavor and aroma elements of your beer? There are several “ingredient” options and at least one “process” option available to you.
Haze makes appearances in both the BJCP and BA style guidelines as a desirable (or simply acceptable) feature of a range of beers, and certainly it has prompted a number of impassioned discussions among IPA enthusiasts. Whether you’re making a light hefeweizen, a fresh Kellerbier, a new-fangled New England−style IPA, or a Franco-Belgian ale, you have plenty of choices that will add that soft glow–inducing haze to your beer.
First, you can make ingredient choices that are more likely to impart haze. In continental beers that we explicitly or implicitly consider “wheat” beers, haze is nearly always a function of grist composition and not of hops usage. Wheat—unmalted wheat, in particular—is more protein-heavy than barley, and several varieties (malted wheat in hefeweizen and Dunkelweizen and unmalted winter wheat in witbier, for example) will make haze much more likely.
Recommended yeasts within these styles also tend to be low-flocculating strains: Weihenstephan and Bavarian Wheat from Wyeast and their corresponding yeasts from White Labs (Hefeweizen and Bavarian Weizen) are popular choices and also impart traditional weizen clove and banana flavors. For those leaning more toward the fields of France than the mountains of Bavaria, there are low-flocculating saison and Kölsch yeasts that are also likely to hang around (literally).
For those who are wandering further afield into the territory of hazy hoppy beers, the options above still apply, at least as far as grist is concerned (more on yeast choice in a moment). If your goal is a creamy milkshake IPA, by all means, take advantage of the additional proteins added by malted wheat. You might also add oats, flaked wheat, flaked barley, or torrified wheat to your grist: not only will they amp up the haze and creaminess, but they will also aid in head retention.
Your ingredient options expand, though, through your hops usage. While some of the beers in the styles noted above might have a meaningful amount of hops (pale bière de garde, for example), it is virtually guaranteed that your IPA, absent filtering, will tack on some haze through its hopping. There is highly mixed information on whether the polyphenol “load” of specific hops strains can be adequately measured or employed to impart haze, but one thing that is certain is that all hops impart polyphenols. In light of that, if your goal is a hazy, hoppy IPA, then your best bet is to use lower alpha-acid aroma hops, both in the boil and in dry hopping, since the increase in the sheer volume of hops will be more likely to add increased levels of polyphenols. You might also consider lower-flocculating yeast strains that do not also add unwanted flavors: several lager strains fit the bill, as does Wyeast’s German Ale strain, and most will not add flavors that compete with your hops-forward beer. And please, for the love of everything holy, do not add flour to your beer to add haze.
Finally, regardless of the style, process adds some alternatives as well. You might consider avoiding a cold crash before packaging to minimize the amount of particles that drop out of suspension. Forego the use of finings. Boil more gently and chill more slowly to minimize the formation of break material. All of these, though, will also be affected by another ingredient that we don’t often think enough about: time. Serving beer young and fresh gives the beer very little time to clear, and as a result, you’re tasting a fuller, more raw interpretation of it. If haze is your goal, time is your enemy—and as haze is also often associated with less flavor stability, drinking the beer young means a greater chance of tasting it at its best.
Not every beer is better hazy (not even many of the traditionally cloudy styles—“crystal” hefeweizen can be a real treat!). Haze is more than just appearance—it imparts flavors, too. If you’re concerned about flavor stability or mouthfeel or flavor contributions or simply prefer the bright jewel tones of a crystal-clear beer, then you can and should use your brewing toolkit to make your beer match your brilliant desires!
Much can be accomplished by simply taking the reverse advice from above. In terms of ingredients, avoid higher-protein grains. Use high alpha−acid hops to minimize the amount of plant material (and, therefore, polyphenols) that makes it into the beer. Choose yeast strains that are quick to flocculate out of suspension (many English yeast strains are notorious for this—for better or buttery worse).
In other ingredient news, a wide array of clarity-promoting finings is at your disposal! The most common are probably Irish Moss or Whirlfloc, a dried seaweed mince or powder that helps coagulate proteins in the boil and thereby helps remove them. Isinglass functions in much the same way and will also aid in precipitating out polyphenols. Gelatin, added post-fermentation, is an effective tool to remove proteins and polyphenols on the “cold” side of the process, which makes it a go-to that you might want to keep on hand if you need to clear a beer in a hurry after it goes into the keg! Some of these finings (Isinglass, at least) will also aid in removing stubborn yeast that refuses to flocculate.
In addition, though, there are active steps you can take to clear your beer. The most direct method is filtration. Filtering your beer physically strips particles out of the liquid, creating an unavoidable increase in clarity. While cold-crashing post-fermentation can cause chill haze in beers susceptible to it, cold-crashing will help a beer clear as proteins and other particulates coagulate and drop out as their density overcomes their buoyancy. One last note about process: although you should always avoid it for flavor and flavor-stability reasons, you should be very careful of oxidation if clear beer is your goal. Oxidation can cause a more permanent haze that does not dissipate even when the beer warms.
Finally, your best friend in the clear beer wars is time. Nearly all beers will clear eventually. Store them cold, dark, and still, and in a relatively short few weeks you will likely see them beginning to clear through the miracle of simple gravity. While permanent haze caused by oxidation or excessive hopping and/or bacterial contamination might resist this method, most beers will respond to it quite well. In more ways than one, wait and see.
Don’t Fear the Haze
Whether a deliberate choice, an accidental result, or a surprising outcome, haze is neither a sign of great things to come nor a signal to begin dumping your beer into the gutter. As with most parts of brewing, we should judge it on its own merits (or challenges). Consider the flavor and visual impacts, compare them to your goals and desires for that beer, and respond accordingly. Whether it’s the best of beers or the worst of beers is, ultimately, up to you.
In Craft Beer & Brewing Magazine®’s online course, Brewing New England–Style IPAs, Steven McConnell, co-owner and head brewer Wild Bones Brewing Co., covers the ins and outs of making the hottest style to hit the market in years. Plus, you'll get 4 recipes from the pros to get you started. Sign up today!