Every year the Salem and Beverly Water Supply Board sends out a water quality report. I imagine it’s a legal requirement and that 99% of residents throw it in the trash like it’s junk mail. I always figured that if there was something truly bad in the water supply it would make the news or somebody smarter than me would understand what the jargon in the water report actually means. As a brewer this is actually relevant information.
The four main ingredients in beer are water, malt, hops, and yeast. The first ingredient, water, usually garners the least attention. In his excellent book Homebrew Beyond the Basics, Mike Karnowski states that brewers typically fall into two camps: those who know nothing about their water, and those who obsessively adjust their water. Until I started this post, I fell squarely in the first category. Homebrewing is as involving as you want it to be, and toying with water chemistry always felt sciency and intimidating. Karnowski only devotes a few pages to water chemistry, but he explained it simply enough that I think it can improve my beer without making me regret all the Chemistry homework I didn’t do in the tenth grade.
Here is the water profile with the information from the Salem and Beverly Water Supply Board 2013 Water Quality Report:
I left the PH blank because that was not indicated in the report and I don’t have a PH tester and certainly don’t have any pool test strips. It is certainly important, but we will leave that aside at the moment.
A significant factor that looks like it is the easiest to adjust is the ratio of sulfate to chloride. Beverly water has an almost 1:3 ratio of sulfate to chloride which is ideal for malt forward beers. That makes me feel better that my last several batches have all been malt forward styles. As you can imagine for a balanced style you would want a more even ratio, and for a hop forward beer like an IPA the ratio should be the exact opposite of what is present in Beverly water. I’ll be sure to let my hop loving cousins know that Beverly water is holding back their IPAs and RyePAs.
Calcium is important for yeast health, and Beverly water is on the low side. Karnowski states that it should be at least 50 PPM, and we’re at 22.8 PPM. For a hoppy beer adding calcium sulfate (gypsum) will increase the calcium and sulfates. Conversely, calcium chloride will increase the calcium and chloride for a malt forward beer. Beverly water is also low in Magnesium, so adding Magnesium Sulfate (gypsum) to get that over 10 PPM is advisable for yeast health. In terms of what exactly to add and how much, there are online calculators and I’ll be sure to share details on water adjustments during future brew day posts.
If you live in a neighboring community that gets it’s water from the MWRA like Boston, here is a profile of Boston water according to BeerSmith. Evidently there is a water section on their mobile app that I didn’t realize existed until this week.
Sourced from Western Mass, it is a lot lower in mineral content than Beverly water from Wenham Lake and the Ipswich River. It is perfect for a balanced beer like Boston Lager. Sam Adams uses Boston tap water to brew it, and replicates this water profile when they brew Boston Lager out of state.
If you don’t like your municipal water and prefer bottled water, here is a profile for Poland Spring Water:
Water can vary like any other ingredient. The data I sourced from the water quality report is from just one reading done over a year period. Since our water in Beverly comes from the same source year-round I feel safe in assuming the variance is minimal. If you are so into water chemistry that you have to know the exact readings of the actual water you intend to brew with, or if you plan on brewing with well water and don’t have a water quality report, a water testing kit like this will get you the data you need.
I have a couple IPAs in development. Gypsum will certainly be in my ingredient list when I go shopping this weekend.