If you’ve ever flipped kegs of hefeweizen upside down or had a beer start to look like one of those snow globes from the airport gift shop, then you understand the frustration of unwanted clarity.
Here, we’re not going to focus on how to make the best hazy IPA, or even how to make the haziest one. Instead, we’re going to focus on haze stability—how to keep that hazy beer hazy. (But if we happen to thread that needle along the way and learn something new about how to make our IPAs more delicious, so much the better.)
To help get a more complete picture of what contributes to haze stability, I reached out to several people across the industry for their thoughts and recommendations, breaking the considerations into two parts: hot side and cold side. I’ve also synthesized their advice into a recipe (page 64) that could be your jumping-off point for taking all these tips out for a spin. With that, let’s mill in and start with the grist.
On the Hot Side
For brewers, haze starts with the mash. Why? Because most stable haze comes from the malt matrix, via proline-rich proteins that later bind with the polyphenols in hops. With that in mind, you need to get some protein into the wort.
Wheat is probably the best source of this protein. Chris Schooley, cofounder of Troubadour Maltings in Fort Collins, Colorado, recommends making it about 20 to 40 percent of your grist.
“Wheat is such a key ingredient,” he says, “as it has a higher percentage of [PRPs] than barley. But also, I wouldn’t recommend messing too much with the parameters on your barley as long as it has solid modification to begin with.”
Oats, on the other hand, aren’t integral to haze stability, Schooley says—though he adds that including them at about 10 percent of the grist can help contribute a luscious mouthfeel.
Some brewers—including Brandon Capps of Denver’s New Image and Doug Reiser of Burial in Asheville, North Carolina—say they focus on flavor over protein density, whether that’s coming from wheat, spelt, or oats, without worrying too much about specific metrics. Yet there’s another metric to consider: the acidity of the mash.
To best extract those proteins, Reiser says, they target a pH close to 5.2, only pushing beyond to potentially drive more attenuation. However, there is evidence that a slightly higher mash pH near 5.4 will keep more protein in solution.
The “pH is god over here,” Reiser says. The commandment is “5.2 is the highest mash pH we will use, and often 5.1, with the aim of landing as close to 5.0 in the boil as possible.
Water plays a role, too. Without getting too deep into the chemistry, I’ll just note that a higher chloride-to-sulfate ratio (2:1 or 3:1) helps set the colloidal particles that contribute to haze. While neither Capps nor Reiser emphasized water treatment, beyond the importance of achieving an ideal mash pH, it’s a good idea to favor chloride while not necessarily abandoning your preferred water profile.
On to the whirlpool: Keep in mind that higher temperatures extract hop polyphenols, which can be haze-positive, along with bitterness and less desirable material—so, as usual, it’s a balancing act.
Reiser says that at Burial, they prefer a lower-temperature whirlpool between 170 and 180°F (77 and 82°C). At New Image, meanwhile, Capps says he first considers which hops can best take the heat; he consults the Yakima Chief Hops survivables chart (see page 67) before making the call.
Assuming you plan to dry hop—another source of polyphenols—you can worry less about extracting them in the whirlpool. Instead, you can use lower temperatures, such as those Reiser specifies, to get the aroma and flavor you want without excessive bitterness.
Hot-Side Recap:
- Use some form of high-protein malt; wheat is best.
- Target a mash pH between 5.2 and 5.4.
- Emphasize chloride over sulfate for water treatment.
- Consider a cooler whirlpool (around 180°F/82°C) with hops that are relatively high in survivable compounds, such as Centennial and Mosaic.
On the Cold Side
Now our beer is in the fermentor. How else can we contribute to stable haze, while also retaining what’s already in the wort?
The most important players here are yeast, which can make or break haze stability.
When yeast are stressed, they release proteases, which begin to break down protein in an effort to scavenge nitrogen. That can cause haze to drop out or, even worse, create the dreaded snow-globe effect.
To prevent that stress, we should ensure a healthy fermentation. Oxygenation and nutrients can help there. Pablo Gomez, technical account manager at White Labs, recommends focusing on oxygen and zinc—specifically, 1 ppm of dissolved oxygen (DO) per degree Plato, and (regardless of gravity) 0.3 to 0.4 ppm of zinc. So, if you’re brewing a hazy IPA with an OG of 1.063—like our recipe—that’s 15.4°P; just aim for 15–16 ppm of DO but 0.3 to 0.4 ppm of zinc.
That zinc comes with a bonus: Having the right amount of it, Gomez says, helps to minimize hop creep by keeping yeast healthy and active throughout fermentation, including the increased enzymatic activity that comes with dry hops. (For more on that phenomenon, see Don’t Be Creeped Out.) For most strains, a standard yeast nutrient should foster healthy fermentation; most of those contain zinc, but be sure to check.
For oxygenation, it may be a good idea to slightly increase the in-line level of oxygen, depending on your setup. Capps, for example, says he’s tinkered with adjusting both New Image’s yeast pitch rate and total DO target to achieve more consistent haze and attenuation. He’s arrived at a pitch rate of 0.25–0.5 million cells per degree Plato and DO target of 18–20 ppm in wort, which is close to Gomez’s recommendation.
For pro brewers, Capps also recommends purchasing a DO meter to dial that in. More affordable options include the sort of oxygen meter made for fish tanks.
When it comes to the choice of yeast strain, keeping haze stability in mind, brewers widely recommend the London III strain for its relatively consistent attenuation and, most importantly, flocculation. (While these aren’t all identical, similar strains include Imperial A38 Juice, Lallemand LalBrew Verdant IPA, Omega OYL-011 British Ale V, White Labs WLP066 London Fog, and Wyeast 1318 London Ale III, among others.)
Both Capps and Reiser cite London III’s ability to create flavorful beers that still have enough body—a key to the style—while not flocculating so much that all the solution-stable hop compounds drop out with the yeast.
Finally, dry hops. As I previously mentioned, warmer temperatures and more time will extract more polyphenols as well as hop astringency. So, you’re best served with a cooler dry hop—say, 52–58°F (11–14°C)—and a shorter contact time that balances the amount of vegetative matter. A few days is enough; many brewers are happy with just one or two.
When choosing those hops, it helps to look at myrcene and overall oil content, as those nonpolar compounds can help to create lasting haze.
“The more hop oil, the better,” Reiser says, “but you have to buffer it with vegetation flavor issues and loss.” This is where many brewers these days are turning to Cryo (or other concentrated lupulin pellets) as well as flowable hop products. At Burial, Reiser says, they often go with a cold-side blend of 60 percent T-90 pellets, 20 percent Cryo, and 20 percent flowable.
“We still do plenty of 100 percent T-90,” he says, “but often not in hazy beer. There’s just too much particulate left in suspension.
Cryo and other hop products are useful tools for better character and yield, and smaller particle size also helps with haze stability. (Look up the research by Karl J. Siebert at Cornell if you want to go deeper on that.) So, using these formats can help you to pack in more hop character while also contributing to a longer-lasting turbidity.
In whatever format, some of the higher-oil hops that brewers mentioned as key drivers of haze include Citra, Galaxy, and Nelson Sauvin, as well as Southern Hemisphere hops in general.
Cold-Side Recap:
- Use yeast nutrient, especially zinc.
- Oxygenate appropriately—1 ppm per °P—to keep yeast healthy.
- Use a strain, such as London III, that doesn’t flocculate too quickly or dramatically.
- Dry hop at cooler temperatures (52–58°F/11–14°C), after primary fermentation, for shorter amounts of time.
- Use hops that are high in total oil content, such as Citra and Galaxy.
- Use different hop formats to balance particle size.
Corrective note: In the printed version of this article, we suggested 0.3 to 0.4 ppm of zinc per degree Plato. That is incorrect—the zinc addition is independent of gravity, while the DO target is per degree Plato. Executive editor Joe Stange wants everyone to know that this was entirely his fault, not Zach’s, and that he regrets the error.
