I brewed 30 batches before I thought about water. Thirty batches of "pretty good" beer that never quite hit the mark — my IPAs lacked crispness, my stouts tasted thin, and my pilsner attempt was so bad I dumped it without bottling. The grain was fresh. The hops were vacuum-sealed. The yeast was healthy. The problem, I finally figured out, was sitting in the kitchen faucet the entire time.
Water makes up 90-95% of finished beer. It's the canvas everything else paints on. And yet most homebrewing guides treat it as an afterthought — "use dechlorinated tap water" is about the extent of the advice. That's like telling a painter to "use canvas" without mentioning whether it's linen or cotton, primed or raw. The surface matters.
This isn't a chemistry textbook. It's the practical water knowledge that took me from "pretty good" to "this actually tastes like the beer I was trying to make." If you're ready to go deeper into the all-grain process where water adjustments matter most, our all-grain brewing guide covers the full picture.
The Six Minerals That Matter
Beer water contains dozens of dissolved minerals, but only six have a meaningful impact on flavor and brewing chemistry. Learn these six and you know more about water than 90% of homebrewers.
Calcium (Ca)
Target range: 50-150 ppm
Calcium is the workhorse mineral. It lowers mash pH (critical for enzyme activity and starch conversion), promotes yeast health and flocculation, improves protein coagulation during the boil, and contributes to long-term beer stability. If you only adjust one mineral, make it calcium. Below 50 ppm, your mash chemistry suffers. Above 200 ppm, you risk a harsh mineral bite.
Add calcium via calcium sulfate (gypsum) to accentuate hops or calcium chloride to accentuate malt. This dual pathway makes calcium your most versatile adjustment tool.
Magnesium (Mg)
Target range: 10-30 ppm
Magnesium is an essential yeast nutrient in small amounts. Most grain bills contribute enough magnesium that additional supplementation is unnecessary. Above 30 ppm, it contributes a sharp, sour bitterness. Above 50 ppm, it acts as a laxative — which is a flavor profile nobody's after. Generally, leave magnesium alone unless your water report shows it below 5 ppm.
Sulfate (SO4)
Target range: 50-150 ppm (up to 350 ppm for aggressively hoppy styles)
Sulfate accentuates hop bitterness, making it sharper, drier, and more assertive. High-sulfate water is why Burton-on-Trent became synonymous with English IPAs — the naturally high sulfate content (up to 800 ppm in some wells) gives Burton ales their famously crisp, minerally hop bite.
For a West Coast IPA, bump sulfate to 200-350 ppm. For a malty Scotch ale, keep it under 50 ppm. The sulfate-to-chloride ratio (more on that below) is the single most impactful water adjustment for flavor perception.
Chloride (Cl)
Target range: 50-150 ppm
Chloride is sulfate's opposite number. It accentuates malt sweetness, fullness, and body. Higher chloride relative to sulfate pushes beer toward round, smooth, malt-forward character. Classic English milds, Scottish ales, and rich stouts benefit from higher chloride levels.
Above 200 ppm, chloride can make beer taste medicinal or salty. And never confuse chloride (the ion) with chlorine (the disinfectant in tap water). Chloride is a mineral you want. Chlorine is a contaminant you need to remove. More on that later.
Sodium (Na)
Target range: 0-75 ppm
Small amounts of sodium (10-40 ppm) round out malt character and add a perception of fullness. It works similarly to salt in cooking — a pinch enhances everything, too much ruins it. Above 75 ppm, sodium becomes detectable as salty. Above 150 ppm, combined with high sulfate, it creates a harsh, unpleasant mineral quality. Most brewing water doesn't need sodium additions.
Bicarbonate (HCO3) / Alkalinity
Target range: 0-50 ppm for pale beers, 100-200+ ppm for dark beers
Bicarbonate is the mineral that buffers mash pH — it resists the natural pH drop that occurs when grain meets water. High bicarbonate means high alkalinity, which means your mash pH stays stubbornly high. For pale beers (where you need a mash pH of 5.2-5.4), high bicarbonate is your enemy. For dark beers (where roasted malts drive pH too low), moderate bicarbonate is your friend.
This is why Dublin's high-alkalinity water produces great stouts and terrible pilsners. The dark roasted malts in Guinness-style stouts need that alkalinity buffer. A pale lager in the same water would taste harsh and astringent.
The Chloride-to-Sulfate Ratio: Your Biggest Lever
Forget the individual mineral numbers for a moment. The single most impactful water adjustment you can make is the ratio of chloride to sulfate. This ratio shifts your beer's flavor balance between malt-forward and hop-forward more dramatically than any other variable.
- Chloride > Sulfate (2:1 ratio): Malt-forward. Round, full, sweet. Great for stouts, porters, amber ales, brown ales, Scottish ales.
- Balanced (1:1 ratio): Neutral. Neither malt nor hops dominate. Great for balanced styles — American amber, English bitter, cream ale.
- Sulfate > Chloride (2:1 ratio): Hop-forward. Dry, crisp, assertive bitterness. Great for IPAs, pale ales, pilsners.
- Sulfate >> Chloride (3:1 or higher): Aggressively hoppy. Very dry, minerally. West Coast IPA territory.
A practical example: my house IPA recipe tasted "good but soft" for two years until I shifted my water from roughly 1:1 to about 250 ppm sulfate and 75 ppm chloride (3.3:1 ratio). Same grain bill, same hops, same yeast. The beer went from "decent pale ale" to "this actually tastes like a proper IPA." The sulfate sharpened the hop bitterness and dried out the finish. One water adjustment, transformative result.
Famous Water Profiles (And What They Tell You)
Historically, brewing cities developed beer styles that suited their local water. The water came first; the style followed. These profiles are useful benchmarks, not gospel.
Burton-on-Trent (English IPA)
Ca: 275 | Mg: 40 | SO4: 610 | Cl: 35 | Na: 25 | HCO3: 260
Absurdly high sulfate. This is the water that made pale ales and IPAs famous. The sky-high sulfate-to-chloride ratio (17:1) creates a dry, minerally hop character that defines the style. Don't replicate this exactly — full Burton water is aggressive. Aim for a scaled-down version: 200-300 ppm sulfate, 50-75 ppm chloride. "Burtonizing" your water for hoppy beers means adding gypsum, not matching Burton molecule for molecule.
Pilsen (Czech Pilsner)
Ca: 7 | Mg: 3 | SO4: 5 | Cl: 5 | Na: 2 | HCO3: 15
Almost nothing. Pilsen's water is essentially a blank canvas — extremely soft, extremely low mineral content. This is why Czech pilsners are so delicate. The soft water lets the Saaz hops and Moravian malt speak without mineral interference. If you're brewing a Czech pils, start with reverse osmosis (RO) water and add just enough calcium (50-60 ppm via calcium chloride) for proper mash chemistry. Less is more.
Dublin (Irish Stout)
Ca: 120 | Mg: 4 | SO4: 55 | Cl: 19 | Na: 12 | HCO3: 315
High bicarbonate, moderate calcium. This alkalinity is what allows Dublin stout recipes to use large amounts of roasted barley without the mash pH crashing. The bicarbonate buffers the acidity of dark malts. Trying to make a Guinness-style dry stout with Pilsen water gives you a thin, astringent mess. Dublin water gives you the smooth, roasty character the style demands.
Munich (German Lager)
Ca: 76 | Mg: 18 | SO4: 10 | Cl: 2 | Na: 1 | HCO3: 150
Moderate alkalinity, low sulfate and chloride. Munich water suits malty German lagers — Märzen, Dunkel, Bock — because the moderate bicarbonate supports Munich malt's lighter roast character without the high alkalinity that Dublin uses for truly dark beers. The low sulfate keeps bitterness soft and smooth.
How to Get Your Water Report
Before you can adjust your water, you need to know what's in it.
Municipal water: Most city water utilities publish annual water quality reports (Consumer Confidence Reports, or CCRs). Google "[your city] water quality report" and look for the mineral content table. You need: calcium, magnesium, sulfate, chloride, sodium, and alkalinity or bicarbonate. Some reports list these as ranges — use the midpoint.
Well water: Get it tested. Ward Laboratories (wardlab.com) offers a Household Mineral Test for about $30 that covers everything you need for brewing. Send a sample, get results in a week. Worth every penny.
RO or distilled water: You already know your profile — it's essentially zero across the board. This is the blank canvas approach. Build your water from scratch using brewing salts. More predictable, slightly more work.
Practical Water Adjustments
You don't need a chemistry degree. You need brewing salts, a gram scale, and a free online water calculator.
The Essential Products
- Gypsum (calcium sulfate): Adds calcium and sulfate. The go-to for hop-forward beers. LD Carlson sells a 1 lb bag for about $5.
- Calcium chloride: Adds calcium and chloride. The go-to for malt-forward beers. About $5/lb from LD Carlson.
- Campden tablets (potassium metabisulfite): Removes chlorine and chloramine from tap water. One tablet treats 20 gallons. A bottle of 50 tablets costs $6 and lasts years. Crush half a tablet into your brewing water and stir — chlorine and chloramine are neutralized in under a minute. If your tap water smells like a pool, this is the first thing you should buy.
- Lactic acid (88%): Lowers mash pH directly. A few milliliters per 5-gallon batch. About $7 for a 5 oz bottle that lasts a year.
- Baking soda (sodium bicarbonate): Raises pH and adds alkalinity and sodium. Use sparingly — it adds sodium, which you generally don't want much of.
The pH Target: 5.2-5.4
Mash pH in the 5.2-5.4 range (measured at room temperature) produces the best starch conversion efficiency, the best flavor, and the best long-term stability. Above 5.6, you extract harsh tannins from grain husks. Below 5.0, enzymatic activity drops and the beer can taste sharply acidic.
A digital pH meter ($15-20 for a basic unit) is the most useful measuring tool in water chemistry. The Five Star 5.2 pH Stabilizer ($8) is marketed as a set-it-and-forget-it mash pH solution — it works in some cases, but it's not magic. It can't fix severely alkaline water, and it can push already-soft water below target. I'd rather measure and adjust than trust a buffer blend. But for beginners who want one fewer thing to worry about, it's a reasonable training wheel.
When to Use RO Water
If your tap water is very hard (above 200 ppm calcium), very alkaline (above 200 ppm bicarbonate), or has high sodium or chloride, building water from RO or distilled is easier than trying to remove minerals. Most grocery stores sell RO water for $0.30-0.40 per gallon from refill stations. A 5-gallon batch needs about 8 gallons of water total (mash plus sparge). At $0.35/gallon, that's $2.80 per batch — the price of a single bottle cap from your favorite craft brewery.
Start with RO, add minerals to match your target profile, and you have complete control. It's the approach most competition-winning homebrewers use, and it eliminates the "my tap water changed seasonally" variable that trips up consistency.
A Simple First Water Adjustment
If all of this feels like a lot, start here. This single adjustment improved my beer more than any recipe change:
- Treat your tap water with half a Campden tablet (crushed, stirred in) to remove chlorine/chloramine.
- For hoppy beers: Add 1 teaspoon of gypsum per 5 gallons of brewing water.
- For malty beers: Add 1 teaspoon of calcium chloride per 5 gallons of brewing water.
That's it. Three steps. The Campden tablet removes the biggest water flaw (chlorine causes medicinal off-flavors — see our homebrewing hub for more on common problems). The salt addition shifts your water profile in the right direction for the style you're brewing. Is it precision water chemistry? No. Is it a massive improvement over untreated tap water? Absolutely.
Graduate to a full water calculator (Bru'n Water is free and excellent) when you're ready to dial in exact profiles. But don't let the complexity of water chemistry stop you from making this one simple improvement today. Your next batch will taste noticeably better.
