Are you measuring the pH in your beer? If not, you’ll probably start after reading this! pH in brewing is critical to at least five aspects of making good beer:

1. Enzymatic Activity
2. Protein Coagulation
3. Yeast Performance
4. Flavor and Stability
5. Hops Utilization

Enzymatic activity:

When mashing, the main goal is to create the conditions needed for different enzymes to convert starches into maltose, other sugars, flavor compounds, and other interesting traits. With a pH outside the range of 5.1 to 5.4, you would see significantly degraded enzyme performance (or none at all). Different enzymes work best at different temperatures, but you shouldn’t think of this as an on/off scenario. For instance, the optimal temperature range for beta-amylase is 140 – 149°F, but you would still find it doing some work in the alpha-amylase range of 154 – 162°F, just less so than the former range. I could write all day about enzymes, so a future post will cover step mashing and the enzymes at work in different temperature ranges. Just know that different enzymes prefer different pH levels, and the effect this has on enzyme performance cannot be understated.

Protein Coagulation:

Maintaining pH levels between 5.1 and 5.4 helps ensure a good hot break, with proteins coagulating during the boil. Hot break is critical for reducing haze-forming proteins and polyphenols, which leads to clearer beer with enhanced flavor stability.

Yeast Performance:

Let’s be honest, making good beer is all about creating the optimal environment for the yeast or bacteria you plan to pitch. The best pH range for most brewing yeast is between 4.0 and 4.5. “But wait!” you say… “I thought we were adjusting the pH of the mash to 5.1 – 5.4!?” Yes. However, during the boil, evaporation, Maillard reactions, break formation, and the addition of hops all contribute to lowering the pH. So, when you pitch your yeast, you are very likely within this range. Some brewers have found great success in acidifying their wort post-boil and have noticed improved flavor stability as a result. Failing to ensure proper pH levels for yeast could lead to off-flavor production, poor yeast performance, incomplete attenuation, and reduced beneficial flavor production (esters/phenols).

Flavor and Stability:

pH plays a crucial role in this area. A decent pH helps reduce oxidation risk, maintains your flavor profile, and prevents infections. This works because if the pH is favorable to your chosen yeast, the yeast will work to prevent other organisms from taking refuge. This is also why open fermentations work. The yeast works hard to ensure that it is the only and strongest organism in the mix by producing alcohol (yes, alcohol production by yeast is a defense mechanism designed to kill other organisms) and growing rapidly to consume all available sugars before something else can.

Finally, Hops Utilization:

pH levels affect the solubility and isomerization of alpha acids from hops, meaning you can ‘extract’ more bitterness with fewer hops and ensure it is not a harsh bitterness. In fact, a pH too low might result in extracting harsh bitterness, while too high might mean not extracting enough bitterness to begin with.

So, pick up a pH meter and start tracking and adjusting this critical metric in your mash and post-boil wort (or during fermentation if brewing a sour or seltzer!). I use this one with good success, and it’s a nice balance of cost to performance: 

https://www.morebeer.com/…/beverage-doctor-pen-style-ph…

---