Great beer has always relied upon great water, from the extremely soft water in lager-loving Pilsen, Czech Republic, to the high-sulfate counts in IPA powerhouse Burton-on-Trent, England. Water was historically essential for transporting casks on barges and boats, and for cooling and cleaning.

Now, in the age of climate crisis, water’s role in craft beer is under increased scrutiny. Small breweries might make better beer, but large breweries are traditionally far more efficient with water usage — and are only getting better at pointing this out to sustainability-minded consumers. Industry giants like AB InBev, for example, issue press releases heralding water-to-beer consumption-production ratios as low as 3.2, which is less than half of what would have previously been considered good for a craft brewery.

As water usage becomes an increasingly urgent matter, small breweries around the world are working to improve their practices.

Much of the leadership on the issue has come from the Brewers Association, the U.S. trade group for craft breweries. In addition to publishing its own water usage and reduction handbook on its website, the Brewers Association has a sustainability mentor, John Stiers, who helps brewers figure out how to improve their water efficiency.

“The No. 1 place to look is cleaning,” Stiers says. “Cleaning in general is the biggest user of water in the brewery. If I walk into a brewery and the floors are wet and there’s a hose running, that’s not a good sign.”

One of the first steps brewers should take, Stiers says, is simply getting a benchmark for their brewery’s water use.

“They just need to take a year’s worth of water usage data, which they have anyway because they pay their bills, and compare it to how much beer they produce,” Stiers says. “If you don’t have a speedometer on your car, how do you know how fast you’re going? Once you collect your utility data, you can have incredible insight into those efficiencies.”

With an idea of where they stand, brewers can try to improve that ratio. One way to start is by double-checking they are accurately following the prescribed process for their clean-in-place (CIP) sanitation systems.

“A lot of brewers may have a spec to CIP for so many minutes, but they’re afraid of bacteria,” Stiers says. “So they say, ‘Oh, let’s just go for twice as long.’”

In Europe, Hamburg, Germany-based Brewtech helps breweries improve water efficiency, among other issues. Brewtech’s technical director Klaus Gollhofer says that while small breweries once considered it acceptable to use between eight and 10 barrels of water for every barrel of beer, the number should be somewhere between four and seven today. His tips include employee training, equipment maintenance, and making sure that the flow of fresh water stops when equipment stops, as well as considering longer brewing schedules with fewer breaks in production. “Try to brew for 24 hours over two to three days, instead of 12 to 16 hours over five days,” Gollhofer says.

In addition to simply using less water to begin with, breweries are finding innovative ways to reuse wastewater. Relatively clean water from the last rinse of the CIP system is saved and used for the first flush of the next clean-in-place cycle at many breweries, including the Czech Republic’s Samson, a small regional producer recently purchased by AB InBev.

“We have a ratio between three and four hectoliters of water to beer,” says Samson brewmaster Radim Lavička. “We have to save water.”

In Colorado, New Belgium saves the water that initially rinses the inside of its clean, new bottles when they come in, according to Katie Wallace, New Belgium’s director of social and environmental impact. The brewery later uses that water to wash the outside of its filled and capped bottles at the end of the packaging process.

“That saved us a million gallons a year,” Wallace says.

Another innovation at New Belgium includes using water treatment to create energy. “We treat our own process water on site, meaning the cleaning water, water from the packaging line and so forth,” Wallace says. “With anaerobic digestion, it creates a hot gas. It’s got a lot of methane in it. During peak hours we actually burn the biogas, and use that to offset our electricity.”

Innovation on multiple fronts seems common in the quest to improve water efficiency. According to Jamie Ramshaw, a former brewer who supervised water usage at several large U.K. breweries and who now works for the British malt manufacturer Simpsons, reducing and reusing water sometimes has its own complications. If wastewater is reduced but the organic waste from the brewery remains the same, that more concentrated waste can wreak havoc on local water treatment plants.

“I know of breweries who are out in villages, and they were just dumping their stuff, and the village water systems couldn’t handle it,” Ramshaw says. “The less liquor or water you’re putting down the drain, the more concentrated your effluent is, and high concentrations of organic material can mess with the local water treatment facilities.”

As a result, small breweries like California’s Bear Republic have installed centrifuges to remove yeast and other solids, thereby sending less organic matter into local treatment plants.

Even the design of new breweries — or a redesign during a renovation — can contribute to better water usage. Brewtech’s Klaus Gollhofer notes that designing shorter pipes between tanks can result in less water being used. Ramshaw says that many classic U.K. breweries were originally built with elements that discourage excess water use.

“You can actually design breweries to be drier,” Ramshaw says. “The microbrewery where I started out had wooden floors. If you look at Hook Norton, it’s got wooden floors, until you get to the cask racking part, that’s where it gets a bit dirty. You can’t spray everything down if it’s got wooden floors, because the water will just go straight through the floor.”

Changing the brewing process can also improve water usage, Ramshaw says, and mentions high-gravity brewing, a process that involves brewing at a higher initial strength and adjusting the beer after fermentation.

“If I brew a beer at 4 percent alcohol, I brew it once and clean it once,” Ramshaw says. “But if I brew the same beer at 6 percent and then dilute it down to 4 percent, I’ve made one and a half times the amount of beer, and used the same amount of water to clean it.”

Although high-gravity brewing is sometimes derided by consumer groups, it can make a big difference in overall water usage. If the choice in the future lies between high-gravity beer and no beer at all, most drinkers would presumably pick the former. Also on the table: brewing with pure, potable water reclaimed from sewage, an idea that is being promoted by the Pure Water Brewing Alliance.

For Stiers, the growing popularity of craft beer makes sustainable water practices all the more important today.

“It’s about changing the culture. It’s about getting employees engaged,” Stiers says. “If you’ve got a sector that is growing as fast as craft beer is in the U.S., you want to do it in the most responsible way possible.”