Most source water in the U.S. has a pH reading of between 6.5 and 8.5, making it more alkaline than the generally agreed upon optimal mash pH range of 5.2 to 5.8. Yeast grows and multiplies much more rapidly at a pH higher than 5.0 (5.5 is optimal), but fermentation is more efficient if the pH reading is below 5.0.

Most normal beers are acidic, in the 4.1 to 4.6 pH range, but a beer with a pH reading much lower than 4.0 can indicate that acid-producing bacteria have spoiled the brew. If you’re not pH testing at every stage of your brewing process, you’re risking the quality of your product, your reputation, and ultimately your bottom line.

What Is pH, and Why Should I Measure It?

Put most simply, a pH reading tells us how acidic or alkaline something is. A pH reading of 7 is neutral, with anything below that being acidic and anything higher being alkaline, or basic. It’s more complicated than that — accurately speaking, a pH reading reflects the concentration of hydrogen ions in a solution — but luckily, the simple definition works for almost all purposes.

Taking an accurate pH reading at every step of the process is essential when brewing your beer. From source water to mash in, on through boil, knock out and fermentation, the pH reading is one of the most accurate QC metrics a brewer can use.

An Accurate pH Reading Is Important At Every Stage

It’s equally crucial for the finished product, as a pH that’s too low indicates likely bacterial infection, and one that’s too high will taste harsh — soapy or metallic. A pH reading in an optimal range means the difference between just brewing beer and brewing high-quality, superior, and consistent beer that will keep customers coming back to your brand.

That’s done through careful monitoring through every phase of the brewing process so that a brewmaster can make any necessary adjustments. The first step is your source water, which is almost always out of the required range for brewing beer.

It All Starts With Water

From Pilsen in the Czech Republic to Burton-on-Trent in Staffordshire in the UK, famous brewing cities worldwide rely on their source water, and even in these historic beer capitals, the water must be carefully checked with accurate pH meters and adjusted to the correct range for brewing beer.

It’s the same all over the world — most municipal water systems deliver water that’s far too alkaline for successful brewing. Getting an accurate water analysis can be difficult, as water profiles change frequently or up-to-date reports aren’t made publically available quickly enough for use in a brewery.

The Need for Accurate pH Meters

It’s up to the brewer to ensure each stage of the brewing process is carried out to exact specifications, and that’s no more important than sparging during the lautering process. The volume of water required to sparge the mash is substantial, and the sparge water must be treated to ensure a proper pH reading.

Food-grade lactic acid and phosphoric acid can lower source water pH to acceptable levels. The brewers must have accurate and dependable pH meters to determine the correct amount of any necessary additives needed for required adjustments.

Dialing in a pH Reading

Producing superlative beer relies on attentive brewing professionals with the tools they need to succeed. Brewing beer is a complex and many-faceted process, and quality pH meters that can deliver accurate pH readings are a must for superior brewing.

Mashing produces particular enzymes, which in turn results in the creation of extract and various amino acids, which imparts flavor and impacts final alcohol production. These enzymes require a pH reading in a narrow range, depending on the beer you’re brewing.

A low acidic mash will result in poor yeast performance and potentially noticeable sensory changes. Knowing how to adjust pH precisely becomes vitally important during the fermentation process.

Fermentation, Yeast, and pH Reading

Wort is most vulnerable prior to the start of fermentation and must be protected from contaminants like wild yeast and bacteria. Wort must be kept sterile, oxygenated, and within an exacting temperature and pH range for brewer’s yeast to grow. Monitoring pH during fermentation is vital to maintaining yeast health and the ability to harvest yeast, ensuring consistent beer sensory and reducing off-flavor creation to maintain a beer’s specific character.

Quality pH meters and being able to rely on an accurate pH reading are essential for more than just specific flavor profiles. The pH of brewing beer drops during fermentation as yeast acidifies the beer. As the beer reaches terminal gravity the pH will rise slightly as yeast reach their death phase and begin to floc out of solution. A pH reading that is lower than expected at this stage can indicate significant bacterial contamination issues or poor yeast health.

The Last Stage: pH of the Final Product

Finally, testing a finished beer can give you insight into its taste, stability, and shelf-life. The pH reading of finished beers should be lower than in the pre-fermentation wort stage and should be within the expected ranges.

A lower reading indicates the presence of bacteria and beer that will taste sour and look cloudy or hazy. A pH reading that is too high indicates a misstep in the first few steps or a potential contaminant.

Knowing the accurate pH reading is vital at every step of the beer brewing process, and dependable pH meters are one of the primary tools of accomplished brewers. Having quality equipment leads to quality processes — and a quality product.

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