The Water Day Workflow: Salts, Acid, and Campden

You have a recipe, malt, and hops, but you also have a stack of white powders that require a specific addition order. Ignoring your water is like ignoring the foundation of a house; if the base is wrong, nothing else sits right.

I spent my first three years brewing without touching water chemistry until a pale ale tasted like cardboard and swimming pool water. That was the day I realized that managing ions and pH is a non-negotiable part of the “garage lab” process.

This guide walks you through the physical checklist I follow every time I brew. It keeps me from dumping salts into the wrong vessel or forgetting to pH-test the mash until it’s too late to fix it.

Source Water Prep: Killing the Chlorine

Before adding anything to your water, you must neutralize chlorine and chloramine used by municipalities. When these meet malt phenols, they create chlorophenols, which taste like medicinal plastic or Band-Aids.

I use Campden tablets because they’re cheap, fast, and highly reliable. One tablet treats 20 gallons of water.

I crush half a tablet, dissolve it in a small cup, and stir it into the brew kettle right after I fill it. Within two minutes, the chlorine is neutralized, providing a clean slate for the rest of the chemistry.

Weighing Salts: Precision measurement

You cannot eyeball salts because different minerals have different densities. Gypsum is lighter and fluffier than calcium chloride dihydrate, meaning a teaspoon of one is not the same weight as the other.

I use a digital gram scale that measures to 0.1 grams. I zero the scale with a small plastic cup and pour the powder until I hit the exact gram count required by my calculator.

I weigh each salt into a separate cup and label them with a Sharpie. Calcium chloride dihydrate is hygroscopic and absorbs moisture from the air, so I store it in a sealed mason jar and work quickly to avoid clumping.

Mash vs. Boil Additions: Strategic Placement

You don’t dump all your salts into the same place. Salts added to the mash affect pH and enzyme activity, while salts added to the boil primarily affect flavor.

Calcium is the most important ion for mash pH. It reacts with malt phosphates to pull the pH down into the 5.2 to 5.6 range where enzymes work most efficiently.

Magnesium sulfate (Epsom salt) can also lower pH slightly, but I mostly use it for sulfate additions in IPAs. If I’m adding more than 2 grams, I split the dose between the mash and the boil to avoid a harsh, metallic aftertaste.

Sodium chloride (table salt) goes in the boil. It doesn’t affect pH much and serves as a flavor addition to enhance sweetness and body in malty styles like Scottish ales.

Acidifying the Mash: The 15-Minute pH Check

Even with the correct salt additions, your mash pH might not land in the target window. This is where 88% lactic acid becomes a vital tool.

I measure mash pH at the 15-minute mark. I pull a small sample, let it cool to room temperature (77°F), and dip my pH meter in.

If the reading is above 5.6, I add lactic acid using a 1 mL syringe. I stir thoroughly, wait 5 minutes, and retest until I hit the 5.2 to 5.6 range.

Do not overshoot. Lactic acid lowers pH rapidly, and bringing the mash below 4.9 will result in a thin, sour beer and broken enzymatic conversion.

Sparge Water Acidification: Tannin Prevention

If you fly sparge, you must acidify your sparge water separately. As you rinse the grain bed, the pH rises; if it climbs above 6.0, you start extracting astringent tannins from the grain husks.

I acidify my sparge water to a pH of 5.5 or lower before I start the process. It usually takes 2 to 4 mL of lactic acid for 3 gallons of sparge water to neutralize the alkalinity.

Do not add salts to your sparge water. Salts in the sparge can over-extract tannins even if the pH is in the correct range.

Putting It All Together

The workflow begins with filling the kettle and adding a Campden tablet. While that sits, I weigh and label my salts before adding mash salts to the strike water.

At 15 minutes into the mash, I pull a sample and adjust pH with lactic acid. While the mash continues, I heat and acidify the sparge water in a separate vessel.

During the boil, I add the flavor salts (NaCl). Once the boil is finished, I chill, transfer, and pitch yeast.

This workflow adds about 15 minutes to the day, but it is leveraged effort from water chemistry. My pale ales are crisper, my stouts are rounder, and my lagers have lost that wet cardboard character.

Brew Day Water Checklist

References

• Palmer, J., & Kaminski, C. Water: A Comprehensive Guide for Brewers. Brewers Publications, 2013.
• Troester, M. “The Effect of Brewing Water Chemistry on Beer Flavor.” Braukaiser.com, 2009.
• UC Davis. “Water Quality for Crop Production.” Department of Land, Air and Water Resources, 2018.