This week on Brew Strong, Jamil and John Palmer dive into brewing water again by tackling some of the basics and answering listener questions on the topic. Here’s a little breakdown of what to expect in this episode:
- How do we improve beer yield? By monitoring and controlling brewing temperature and pH because these factors control the enzymes that make the wort.
- How do we control pH by adjusting brewing water? We can add water hardness, calcium and magnesium, or use acids to lower the mash and wort pH, or we can add alkalinity to raise mash and wort pH.
- Pale beer worts typically need help getting the mash and wort pH down to 5.2-5.6 at room temp.
- Dark beer worts typically don’t need help getting down to that range, but instead may go too low and need some extra alkalinity to bring it back up. This is where the concept of residual alkalinity comes in: it is the difference between the water hardness’s effect to lower mash pH and water alkalinity’s effect to raise mash pH. A residual alkalinity number of zero will not change mash pH. A negative RA will lower pH and a positive RA will raise mash and wort pH. The pH of the mash and wort is a three way balance of the base malt, which is alkaline with respect to the 5.2-5.6 target, the specialty malts, which are typically acidic with respect to the mash pH target, and the water residual alkalinity, which we can adjust depending on whether we need to go up or down. It is much easier to raise RA than lower it.