In this video, Mike walks through his deep dive into mash pH and water chemistry. He collected mash pH data across fifteen beers using a proper pH meter. The goal was to understand how mash pH affects attenuation, clarity, and overall beer perception.
This video is a long one but it’s well worth it for the data and the conversation
What Mike Presented
Mike compared mash pH readings from a pH meter, pH strips, and BeerSmith predictions. The meter consistently read higher than strips, which tended to run about 0.5 lower. BeerSmith predictions tracked closely with measured values when water chemistry inputs were accurate.
He showed how calcium additions generally lowered mash pH through phosphate reactions. Higher bicarbonate levels raised mash pH, especially when working with very soft water. Beer color alone did not correlate strongly with mash pH once salts were adjusted intentionally.
To test whether these differences mattered in the glass, Mike brewed three identical amber ales. The only difference was water source and mineral additions.
Amber Ale Test Recipe
Grain Bill:
86% Pale Malt
8% Crystal 40
4% CaraVienne
2% Carafa Special II
Hops:
1 oz Tettnang at 60 minutes
0.5 oz Tettnang at 5 minutes
Yeast:
Cellar Science Cali
Mash:
152°F for 75 minutes
Fermentation:
68°F for approximately 10 days
Water Treatments:
Beer 1: Straight tap water with Campden
Beer 2: Straight spring water with no additions
Beer 3: Spring water with calcium and bicarbonate additions
Mash pH landed at roughly 5.3, 5.4, and 5.5 across the three beers. Attenuation ranged from about 77% to 82%, with only minor differences.
In tasting, the tap water beer leaned maltier but felt less bright. The untreated spring water beer tasted the most balanced and pleasant. The heavily treated water beer finished drier but showed a noticeable mineral character.
What We Learned About Mash pH
Mash pH within the typical 5.2 to 5.6 range did not strongly impact attenuation here. Good fermentation practices likely play a larger role in achieving dryness.
pH strips are usable for spot checks if you understand their limitations. Starting with soft water simplifies both pH control and flavor balance.
Mash chemistry matters most when brewing at style extremes or with challenging water.
BREW ON!