Wort pH and its Effect on Hops and Bittering

A listener to my recent BrewStrong interview asked about why malty beers tend to be better when the wort pH is around 5.2 and hoppy beers tend to be better when the wort pH is around 5.4.

That recommendation for higher pH for the hoppy beers and lower pH for malty beers comes from Colin Kaminsky and AJ DeLange, my colleagues for the Water Book.

It makes sense when you think about it for a moment. Its pretty well known that hops contribute alpha ACIDS to the wort. When you lower the wort pH, you reduce the chemical "incentive" for those alpha acids to be extracted into the wort. This is in part because the wort acts as a Conjugate Base with respect to the alpha acids. The more basic the wort pH, the more likely the alpha acids will be extracted and reacted into the wort.

This effect can be quickly exhibited if you allow the wort pH to rise well above the desirable pH limit of around 5.6. Then the hops and their flavor in beer can become rough or coarse. Likewise when brewing a malty beer, a low wort pH helps reduce the extraction of bittering and other rough flavors from the hop plant materials.

So when aiming for a certain hopping and bittering character in your beer, recognize that wort pH has an important effect.