Chlorine and chloramine in municipal tap water can mess up your beer’s flavor. When these disinfectants make it into your beer, they create off-flavors that taste like swimming pool water, throat spray, or Band-Aids. Even a small amount of chloramine contamination can result in a plastic-tasting beer that is not at all appealing. More than 22 percent of U.S. water treatment facilities now use chloramine, and that number keeps climbing. Chloramine removal brewing is essential for clean-tasting homebrew. The compound sticks around way longer than regular chlorine and won’t evaporate or boil off. Beer makers understand just how important water quality is to the overall taste of the beer they brew, and the purity of the water used in breweries is essential to making great-tasting beer. Once you understand what chloramine is and how to deal with it, fixing the problem is straightforward and inexpensive.
Table of Contents
- What Is Chloramine?
- Why Chloramine Is Bad for Beer
- Chlorine vs Chloramine
- Campden Tablets
- Carbon Filtration
- Reverse Osmosis
- Best Method for Homebrewers
- Clean Water, Clean Beer
What Is Chloramine?
Chloramines form when water treatment facilities combine chlorine and ammonia, creating a more stable disinfectant than chlorine alone. That stability keeps tap water safe from the treatment plant to your kitchen. The switch to chloramines is relatively simple—water authorities just treat water with ammonia along with chlorine, and this combination causes chloramines to form.
The reaction created by mixing ammonia and chlorine produces monochloramine, dichloramine, and trichloramine. Most of what reaches your tap is monochloramine, since dichloramine and trichloramine tend to be volatile and escape from the water soon after treatment. When you get water at your brewery, only monochloramines and some free chlorine remain.
Water treatment plants switched to chloramine after the 1970s when researchers discovered problematic byproducts from chlorine. Chlorine disinfects, but it produces potentially harmful disinfection by-products called trihalomethanes (THM), which are volatile organic chemicals that can cause cancer. Chloramine creates fewer disinfection byproducts and maintains residual disinfectant presence better than free chlorine, making it the preferred choice for large water systems.
Chloramine has gained popularity for several reasons: it’s quick dissolving with water, it’s more stable than chlorine, and it stays in the water for a much longer period of time. This extended presence makes it ideal for protecting water as it travels through miles of distribution pipes.
Related: Water Profile in Beer Brewing: A Beginner’s Guide
Why Chloramine Is Bad for Beer
When chloramine or chlorine meets phenolic compounds from malt during brewing, they create chlorophenols. Most people describe the taste as medicinal, like Band-Aids, or plasticky. Chlorophenols have incredibly low flavor thresholds—some people can detect them at concentrations under 10 parts per billion. These off-flavors don’t fade with time or conditioning.
The water that is used for brewing beer will have a huge impact on the taste of the finished product. What makes chloramine particularly frustrating for homebrewers is its persistence and potency. Even trace amounts that you can’t taste in your tap water can create noticeable off-flavors in your finished beer.
The chlorophenol reaction happens during the brewing process itself. When your mash or wort comes into contact with chloramine-contaminated water, the chlorine component bonds with naturally occurring phenolic compounds from your malt. This chemical reaction is irreversible—once those chlorophenols form, they’re permanent fixtures in your beer.
Key problems chloramine causes:
- Medicinal or Band-Aid flavors
- Plastic or antiseptic tastes
- Detectable at extremely low concentrations
- Permanent once formed in beer
- Cannot be aged out or masked
Chlorine vs Chloramine
Free chlorine evaporates from water easily when you heat it or leave it exposed to air. Fill your brew kettle the night before, and most of the chlorine will gas off by morning. Boil the water, and you’ll drive off even more. Removing chlorine from water is a fairly simple process—the chlorine will evaporate from water that is left exposed to air on its own in a short period of time, or the water can be boiled to remove it.
Chloramine operates differently. The chloramine molecule is much more stable than free chlorine and stays in solution regardless of organic load or temperature. You can boil chloramine-treated water all day, and it’ll still be there, ready to affect your beer. Leaving it out overnight won’t help either—chloramine persists for weeks, not hours.
Unfortunately, removing chloramines from water isn’t as simple as chlorine removal. Chloramine stays in the water for a longer period of time than chlorine, so you cannot just let the water sit out for 48 hours to remove it. Boiling the water doesn’t work either. This fundamental difference means brewers need to take active steps to remove chloramine—passive methods that work for chlorine simply won’t cut it.
This stability difference explains why water companies made the switch. What makes chloramine effective for keeping water pipes safe makes it problematic for brewers who rely on simple evaporation methods. The same chemical properties that prevent chloramine from dissipating in distribution systems also prevent it from leaving your brewing water without intervention.
Key differences:
- Chlorine evaporates easily; chloramine does not
- Boiling removes chlorine but not chloramine
- Chlorine dissipates overnight; chloramine persists for weeks
- Both create chlorophenols in beer
- Both need removal before brewing
Campden Tablets
Campden tablets containing sodium or potassium metabisulfite effectively eliminate both chlorine and chloramine. Drop one tablet into 20 gallons of water, stir, and wait about 20 minutes. The metabisulfite forms sulfur dioxide when it dissolves, which reduces chlorine to harmless chloride while getting oxidized to sulfate.
The sulfites only treat the water, and when added well before brewing, they lose potency by the time your wort hits boiling temperatures. Any trace amounts of sulfur dioxide evaporate during the boil, leaving fermentation and yeast activity unaffected.
The beauty of Campden tablets lies in their simplicity and reliability. Unlike filtration systems that can become saturated or lose effectiveness over time, each tablet delivers consistent chloramine neutralization. You can crush the tablet for faster dissolution or drop it in whole—either way, the chemical reaction starts immediately.
For practical brewing purposes, most homebrewers add their Campden tablet when they first fill their hot liquor tank or brewing kettle. By the time you’re ready to start heating your strike water, the chloramine is already neutralized. Some brewers add it the night before brew day, though this isn’t necessary—the 20-minute contact time is sufficient.
Key advantages:
- Works on both chlorine and chloramine
- Inexpensive and widely available
- Fast-acting (20 minutes)
- One tablet treats 20 gallons
- No equipment installation needed
Carbon Filtration
Standard activated carbon filters work for chlorine, but chloramine requires catalytic carbon or granular activated carbon (GAC) with sufficient contact time. Regular carbon can remove chloramine, but it needs way more contact time with water than most residential systems provide. Using a granular activated carbon (GAC) filtration system is the most effective way to remove chloramines from water and make a great-tasting beer.
Catalytic carbon enhances the natural ability to promote chemical changes in contaminants, breaking down chloramine much faster than standard carbon. Catalytic carbon can have peroxide numbers as low as 8, while conventional carbon sits around 40 or higher. The lower the peroxide number, the better the catalytic activity and chloramine removal capability.
GAC filtering not only removes chloramines and chlorine, but it also reduces the levels of other harmful contaminants like industrial chemicals, pesticides, trihalomethanes, and other halogenated organic compounds. It is also effective in removing bad odors and tastes.
When choosing a carbon filtration system for brewing, you have options. A cartridge-based system is sufficient when you are using water at a slower flow rate, typically less than two gallons per minute. Cartridge-based systems can handle thousands of gallons before needing replacement and work well for homebrewers who fill their brewing water ahead of time.
To make sure that your system is sized correctly, you should anticipate that you will need two to three times the contact time that is required for chlorine reduction. This extended contact time is crucial for effective chloramine removal.
For larger operations or those needing higher flow rates, the backwashing tank system uses a tank that is filled with GAC granules through which the water flows. There is a valve that can be opened to back-flush the granules to clean them. This is a better option when you have a required flow rate that is greater than two gallons per minute.
Key considerations:
- Catalytic carbon or GAC required (not standard carbon)
- Higher upfront cost than Campden tablets
- Provides chloramine-free water from the tap
- Filter cartridges need periodic replacement
- Contact time must be 2-3x longer than for chlorine
- Good for frequent brewers
Related: Water Conservation in Brewing: Simple Steps Every Brewery Can Use
Reverse Osmosis
RO systems push water through an incredibly fine membrane with pore sizes around 0.0001 microns, removing not just chloramine but also dissolved minerals, heavy metals, and other contaminants. Most systems include multiple carbon pre-filters, and because the RO process is so slow—literally one drop at a time—the water gets extended contact time with those carbon filters.
This slow processing is actually an advantage for chloramine removal. While the extended contact time would be impractical for whole-house filtration, it’s perfect for RO systems that store purified water in a tank for later use. The carbon pre-filters have ample time to break down chloramine molecules before the water even reaches the RO membrane.
RO water provides a blank slate for water chemistry—you can build your water profile from scratch to match any beer style. Brewing a crisp pilsner? Start with pure RO water and add just the minerals you need. Want to replicate the famous Burton-on-Trent water for a classic English pale ale? RO water lets you dial in the exact mineral composition.
This level of control appeals to advanced brewers who understand water chemistry and want to optimize their recipes. Different beer styles benefit from different mineral profiles—sulfates enhance hop bitterness and crispness, while chlorides promote malt sweetness and fuller body. With RO water, you’re not fighting against whatever minerals your municipal supply provides.
RO systems waste water during purification, typically sending several gallons down the drain for every gallon of purified water produced. They’re also slower to generate water than turning on your tap, so you’ll need to plan ahead and fill brewing water the day before. Pure RO water won’t have the mineral content most beer styles need, so you’ll need to add minerals back using brewing salts or water additives.
Despite these drawbacks, many serious homebrewers and all commercial breweries consider RO systems essential equipment. The ability to start with consistent, predictable water quality eliminates one of the biggest variables in brewing.
Best Method for Homebrewers
For most homebrewers, Campden tablets are the practical choice—they’re inexpensive, effective against both chlorine and chloramine, and require no installation or maintenance.
One tablet treats 20 gallons of water and costs pennies. You crush it, toss it in your water, stir, and wait 20 minutes. No plumbing modifications, no filter cartridges to track and replace, no wasted water going down the drain. A small jar of Campden tablets costs less than a single batch of ingredients and will last through dozens of brew days.
Carbon filtration makes sense if you’re brewing multiple batches weekly or want chloramine-free water for other purposes like cooking or drinking. The upfront cost is higher, but you’ll save time not having to remember the Campden tablet step on every brew day. You do need to make sure that you know how much carbon you need to provide sufficient contact time to remove all the chloramine and chlorine. Speaking with a filtration professional can help you size your system correctly.
RO systems are excellent for brewers who want complete control over water chemistry and don’t mind the extra complexity and water waste. If you’re serious about water profiles and building recipes from scratch, RO gives you that capability. Many brewers start with Campden tablets, then upgrade to RO once they’ve mastered basic brewing and want to take their water chemistry to the next level.
The decision often comes down to your brewing frequency and goals. Brewing once or twice a month? Campden tablets make the most sense. Brewing weekly and want to eliminate all variables? Consider carbon filtration or RO. Competing in competitions or going pro? RO is practically mandatory for consistency.
But if your tap water tastes good and you just need to knock out chloramine, Campden tablets will get you most of the way there for less than the cost of a six-pack. Start there, brew a few batches, and only upgrade if you’ve got specific water chemistry goals that require more sophisticated treatment.
Clean Water, Clean Beer
Chloramine removal brewing doesn’t have to be complicated. Campden tablets offer the simplest solution—one tablet treats 20 gallons in 20 minutes, eliminating both chlorine and chloramine for pennies per batch. Catalytic carbon filters provide chloramine-free water straight from your tap if you’re brewing frequently, while reverse osmosis systems give complete control over water chemistry. The key takeaway? Chloramine creates chlorophenols that produce Band-Aid and medicinal flavors you can’t age out. Unlike chlorine, chloramine won’t evaporate or boil off, so you need an active removal method. Start with Campden tablets, then upgrade to permanent solutions as your brewing operation grows. Your beer’s flavor depends on it.