Club Posts

Baltimore’s Water: The Goods

We’ve seen where it comes from. We know how it gets here. So let’s talk about Baltimore’s water. What’s in it? And what does that mean for Baltimore area homebrewers?

The Baltimore Department of Public Works publishes a water quality and a water content report annually. The first report demonstrates to the public that the municipal water is safe to drink. The second report provides a mountain of data for anyone interested in a in depth look at what’s coming out of their tap. DPW monitors the water leaving each plant and records monthly data points across 23 different categories.

Using the information from the 36 months beginning in 2015 and ending in 2017, we get a picture of what Baltimore are brewers are dealing with and how it changes over time. The water leaving the Montebello and Ashburton plants is:

  • remarkably similar; and,
  • remarkably consistent.

Brewing Water Report

As brewers, we tend to focus on a subset of water attributes that are known to have great impact on the brewing process and finished product. The 2017 averages (all measurements are in ppm except pH) for those brewing centric categories are:

Montebello Ashburton
2017 Low High 2017 Low High
pH 7.8 93% 102% 7.8 98% 103%
Hardness (CaCO3) 116 96% 104% 80 93% 104%
Calcium (Ca) 30 94% 110% 21 93% 112%
Magnesium (Mg) 9 94% 107% 6 97% 106%
Sodium (Na) 20 88% 113% 19 91% 107%
Sulfate (SO4) 17 85% 122% 13 91% 135%
Chloride (Cl) 53 91% 123% 42 98% 103%

Baltimore’s water is low-moderate in hardness and is relatively low in flavor ions (chlorides being the exception). Ashburton water is a touch softer than Montebello, but across the board the water content is largely the same. All told, it’s a great starting point for brewers.

Mr. Consistency

Month-to-month the water changes very little, drifting off its averages about 5% in either direction. Further, when we look year over year, the levels recorded in the data set are quite stable.

2015 2016 2017 3-Year Avg Std % Std
pH 7.8 7.8 7.8 7.8 0.01 0%
Hardness (CaCO3) 106 106 116 109.2 5.51 5%
Calcium (Ca) 28 29 30 28.9 0.87 3%
Magnesium (Mg) 8 9 9 8.7 0.37 4%
Sodium (Na) 24 21 20 21.7 2.04 9%
Sulfate (SO4) 20 16 17 17.9 2.08 12%
Chloride (Cl) 64 52 53 56.3 7.08 13%
2015 2016 2017 3-Year Avg Std % Std
pH 7.8 7.7 7.8 7.7 0.05 1%
Hardness (CaCO3) 73 74 80 75.5 3.55 5%
Calcium (Ca) 20 21 21 20.5 0.67 3%
Magnesium (Mg) 5 6 6 5.8 0.32 6%
Sodium (Na) 20 19 19 19.2 0.53 3%
Sulfate (SO4) 12 12 13 12.5 0.90 7%
Chloride (Cl) 43 41 42 42.0 1.04 2%

So now that we know what’s in it, what does it mean?

A Tale of Two SRMs

If you’re on municipal water it doesn’t matter much which plant you are drawing from when managing your mash pH. Let’s examine the stories of two very different beers. In both examples, we’ll assume a batch sparge system with 75% efficiency & typical volumes, a target of 5 gallons into carboy, and an original specific gravity reading of 1.050; some fairly common targets and methods.

We’ll start by brewing a pale beer, say a pilsner. For our girst we’ll use 100% Pils Malt and treat our Baltimore tap water with only a Campden tablet for Chlorine. How much Acidulated malt do we need to hit a a target mash pH of 5.3?

  • On the Montebello Supply we’d need 5.1%.
  • On the Ashburton Supply we’d need 4.9%.

Now let’s consider the other end of the spectrum. A stout with a grain bill of 80% UK Pale, 10% C80, & 10% Roast Barley. How much Acidulated malt do we need to hit a target mash pH of 5.3?

  • On the Montebello Supply we’d need 2.1%.
  • On the Ashburton Supply we’d need 1.8%.

The amount of Acidulated malt required for each beer is almost identical regardless of the municipal source. Both sources are comparably low in Calcium, Sulfate, and Chloride, making it fairly straightforward to adjust the flavor ions using Gypsum (CaSO4) and Calcium Chloride (CaCl2). Additionally, if the water isn’t soft enough for your brew diluting with to a 1:1 ratio with distilled water will approximate the famous Pilsen water profile to a surprising degree.

Wrapping It Up

All considered, Baltimore’s municipal water is an asset to any local brewer and, with minimal effort, can be tweaked to a variety of profiles. Perhaps it is no wonder that Baltimore developed a rich brewing tradition rapidly after founding.

No matter how you decide to manage your water on brew day we hope this series of articles has shed a little light on the history, operation, and content of the Baltimore municipal water supply. The water here has the potential to make great beer.

Cheers and happy homebrewing!


  1. Baltimore tap water contains low levels of free chlorine. There are many strategies to remove it.
  2. Baltimore occasionally pulls water from the Susquehanna during times of drought or excess demand. There may be intermittent periods when the water profile differs significantly from the data shown here.
  3. This data is taken from water leaving the filtration plants. While many of our club members report it as being consistent with water content tests from their home faucets, getting a water report from your tap is the recommended way to calibrate your brewing water calculations.



Baltimore’s Water: The Journey

Last week, we traveled from the beer in our glass back to the genesis of our brewing water. To the streams and rivers the City of Baltimore captures to provide a vast amount of freshwater for its citizens and industry. It is this water, from the Gunpowder Falls and Patapsco River (and occasionally the Susquehanna), that makes up the largest portion of our finished beer.

But let’s be honest, we’re not really brewing with river water are we?

Our public waterworks are a massive network of dams, pipelines, treatment processes, filtration mechanisms, and distribution systems all working in concert to deliver clean water to our homes and businesses. Put a glass of water from Loch Raven and one from the kitchen sink side-by-side and I know which one I’d rather put in my kettle. Our water undergoes an enormous transformation before it ends up at our faucet.

The journey starts when water from the city reservoirs is transferred via underground pipeline to one of the two filtration sites at Montebello or Ashburton. Water from the Loch Raven reservoir is gravity fed to Montebello (plants I and II) while water from the Liberty Reservoir is transferred to the Ashburton Plant. So while the plants may treat the water with the same processes they begin with different supplies.

A map of the Baltimore water service area & supply & treatment facilities.

The reservoirs themselves play the first part in cleaning our water. The dams that feed the filtration plants are a great place for some particulate to settle and rough filters at the reservoir keep out large pieces of debris.

Arriving at one of the treatment plants, the water is subjected to Pre-Chlorination. Chlorine kills bacteria, protozoa, and viruses as well as prevents the growth of algae during the treatment process. The city adds enough of the chemical at the start of the process to target a residual level of 1 ppm chlorine in the distribution network. This level is necessary to prevent any regrowth on route to customers.

After this preliminary chemical treatment the water is still full of suspended impurities. What are these things and why are the suspended? The impurities are charged colloids and very light particulate. Animal waste, air pollution, and surface runoff are some of the chief contributors of this matter that refuses to sink either because of its charge or its density.

Fortunately, there are methods to encourage the particles to drop out of our water. This step is Coagulation & Flocculation.  Aluminum Sulfate (alum) is added to the water which is then rapidly mixed. The solution is transferred into large tanks with slowly rotating paddles that encourage the alum and the particulate into contact. The particulate clumps together and the clumps continue to combine as they encounter each other.

The impurities are now heavy enough to drop out of the water during the next process, Sedimentation. The water is transferred into a set of long tanks where is slowly makes its way from one end to the other. This lazy journey allows the flocculated material to fall to the bottom of the tank just like yeast groups together and drops to the bottom of our carboys as fermentation completes. Water is drawn off the top of the tank, leaving much cleaner than it entered, and the debris is periodically scrapped from the bottom of the sedimentation tanks.

The water is now ready for its last mechanical cleaning process, FiltrationWhat’s happening here isn’t really much different than what happens when you fill up a filtered water pitcher. The water enters the top and is forced through a bed of sand and gravel, stripping out small particles and other impurities. Clean water exits the system from the bottom and is pumped to holding tanks to undergo final adjustments. Each plant contains a bank of filters which are backwashed on a rotating schedule to clean the filter media and ensure uninterrupted service.

Baltimore City performs three post-filtration adjustments before the water enters the city distribution network. Fluoride is added to the level of 0.7 ppm, Chlorine is added (if needed) to reach a level between 0.2 & 1 ppm, and the pH of the water is raised to 8 using Calcium Oxide (lime). These final adjustments promote dental health, ensure the treated water remains clean as it travels for delivery, and protect against leeching from pipes in the distribution system.

Depending on where your home or business is located in the city you’ll find yourself inside one of Baltimore Department of Public Works many distribution zones.

A map of the Baltimore municipal water zones.

Water from Montebello and Ashburton serves zones 1 & 2 via gravity while being pumped to the others. The cleaned and treated water ends up in taps all over Baltimore City and parts of Anne Arundel, Baltimore, Carroll, Harford, & Howard counties. DPW tests and publishes reports on the water quality & content as it leaves the plants and samples water from taps all over its network to monitor the integrity of the city supply.

So enough already! Baltimore’s waterworks are certainly impressive. A lot of effort goes into the capture, cleaning, and delivering our drinking water. As Baltimore area brewers we’re plenty interested to see what’s in it.

Up Next: Baltimore's Water: The Goods!

Baltimore’s Water: The Genesis

Beer! What is it?

As brewers, we often think of our beers as a recipe: a combination of malts & sugars, hops, yeast, and other flavorings. We talk of phenols, esters, and aromatic compounds that play with our grain bill to produce finished beverages. Our beers can be barrel aged, fruited, dosed with brettanomyces or finished with tinctures of cocoa & vanilla. Yet, when we break a prototypical beer into some very basic categories one item dominates.

Water. Plain. Simple. H2O.

It’s fair to say the other parts of beer add strong flavors and aromas to the drink, driving the character of our finished homebrew.  Still, no matter how we choose to craft our recipe and handle the production all those ingredients and processes must sit upon a canvas of water.

The water you brew with has a measurable effect on your final product. It drives interactions in the mash (pH) & boil (break, hop utilization) and affects flocculation & other cold-side processes. It contains flavor ions that contribute character (calcium, sodium, magnesium, sulfates, and chlorides) and shape the profile of the beer.

So what does that all mean to us as homebrewers? There is a boatload of literature and a heap of anecdotes detailing how water affects beer. Baltibrew even had a QC technician from a local brewery come out to give a talk on his philosophy regarding water treatment. For the modern homebrewer information and opinions on how to handle your water abound.

So what about Baltimore's water?  It turns out Baltimore water has a reputation as great brewing water!

Let’s dig a little deeper into this aquatic topic. Where does this water come from? How does it get to our faucets? And what’s in it, anyway?

The Baltimore municipal waterworks draw water from three sources, all of which are surface water. The big name in the mix is Loch Raven Reservoir.

Loch Raven Reservoir and dam. It provides drinking water for the City of Baltimore and most of Baltimore County, Maryland.

Located just north of the city, Loch Raven Reservoir and the upstream Prettyboy Dam impound the waters of the Gunpowder Falls. Prettyboy’s function is to keep the level in Loch Raven constant, important because this water is fed to treatment plants via gravity. The two dam system ensures there is enough pressure on the water for it to make the trip via underground pipeline for treatment at one of Baltimore’s filtration plants.

Next up, Liberty Reservoir.

Liberty Reservoir Dam, Baltimore County and Carroll County, Maryland

Located to the northwest of the city this dam holds water from the Upper Branch of the Patapsco River. The combined watersheds of these three reservoirs pull water from the north & west of the city and extend as far as southern Pennsylvania.

A map of the Baltimore reservoir watersheds. (2006)

Finally, a pipeline arrives from the northeast that can pump water south to Baltimore from the Susquehanna River. Currently, the Department of Public Works only draw from this source during periods of high demand or drought. Projected growth of the region forecasts the need to pull water from the Susquehanna on a regular basis by 2025. These sources hold 86 billion gallons of fresh water for city and parts of the surrounding counties. They represent over a century's worth of public works projects to secure a quality and consistent water supply for the city.

The history of Baltimore's public water supply goes even further into the past and features a name not typically associated with clean, tasty water. The city's first successful water distribution system pulled from the pristine, picturesque...Jones Falls.

A screen placed across Jones Falls traps trash and keeps it out of Baltimore harbor. Although not foolproof-a heavy rain can break the screen-it is effective when cleaned regularly.

Over 200 years ago it looked a bit different (and modern restoration efforts of the Jones are ongoing).

Cut and bridge on the railroad at Jones Falls, Baltimore.

After several failed legislative attempts to create a public waterworks (starting in 1797) a stock company was formed in the early 1800s that impounded the Jones at Calvert & Center Streets. This company improved many aspects of its water system and was eventually sold to the city in 1854 for the sum of $1.35M. Public expansions of the system continued.

The Druid Hill Reservoir was completed in 1873. The Gunpowder Falls was captured in 1881 with Loch Raven Dam completed in 1915. In response to public health concerns the city began chlorination of its supply in 1910. The Montebello Filtration Plants (I and II) went online in 1915 & 1928. To keep up with demand the Liberty Dam was completed in 1954 and the Ashburton Filtration Plant began its operation in 1956. The system now produces 360M gallons of drinking water every day to meet the needs of its residents and business, a true feat of modern engineering.

As Baltimore area homebrewers if you start your brew day by opening the faucet to fill a kettle these are the waters you pull from. Every time we crack a homebrew it is the end of a long journey down the Gunpowder Falls & Patapsco Rivers and through a public water system designed & built over hundreds of years.  A journey that passes through our recipes, our kettles & carboys, and ends right in our glass.

Cheers and Happy Brewing!

Next up: Baltimore's Water: The Journey!

May Meeting Minutes

Baltibrew General Meeting

May 17, 2018 @ Jon's House

  • Introductions

  • Guild Update - Kris

    • There are lots of guild events coming up, please check the calendar and listserv for updates. Minutes from the meeting are available for review. (Guild Minutes May 2018)
  • Bylaw Revisions - Status Update

    • An e-board is meeting next Tuesday. The bylaw changes will be on the agenda for that meeting. More to come.
  • Discussion of Baltibrew Events

    • Brubakes Recap
      What a great event! Thank you to all the contestants and attendees. Paul from De Kleine Duivel is be interested in hosting again next year with an increased number of tickets. Attendance this year was about 40-50.
    • Brewtherville Big Brew Recap
      Greg and Christoph dropped in on Brewtherville’s event. BC Brewery looks great and the beer is tasty. They have filled 18 of their 24 taps and looks to have the space to grow their operation considerably. It’s right off the light rail. Anyone who has a chance to check it out should drop by.
    • Sensory Classes @ Jon's
      Due to scheduling conflicts the dates of the tasting panels have been moved to July 14th/15th. Reach out to Jon to sign up. The cost is $20 for one session, $35 for the pair.
    • Orioles Outing
      July 28th is the same day as Union Collective grand opening which many members plan to attend. Since the tasting panel has been moved to July we’re going to cancel the July Orioles outing in lieu of supporting Jon’s event and the Union event.
    • August Bus Trip
      Greg and Jacob are working up the itenary. More to come on this trip. Looking at an early August weekend.
    • ChiliBrew XII
      Anyone interested in helping out with ChiliBrew should contact Jacob. Baltimore Beer Week has not finalized the exact week in October yet. Since we try to schedule ChiliBrew as a kickoff event we’re waiting on that decision. It will likely be October 12th but could possibly be on the 19th. Stay tuned.
  • Social/Event Updates - Jacob

  • Other New Business/Member Announcements

    • Feedback Sheets for Beer Evaluation @ Meetings
      The Baltibrewer survey revealed the desire for a slightly more formal procedure to request feedback on homebrew during the monthly meeting. A draft feedback sheet based on the BCJP score sheet was circulated. The general consensus was that it was too busy. A revision featuring more hedonistic categories will be available at the next meeting.
      Draft Homebrew Feedback Label
      Draft Homebrew Feedback Form
    • Iron Brewer Update
      Due to waning interest in the current Iron Brewer format, the contest will change from a recurring Chopped format to more of an on-demand Bobby Flay’s Throwdown competition. The rules discussed were:

      • There is no scheduled Iron Brewer contest.
      • Any club member may challenge the current Iron Brewer to a competition on a given style/ingredient.
      • It is up to the challenger and the Iron Brewer to come to a gentlepersons agreement on when the finished beer will be judged. We can’t expect the Iron Brewer to defend challenges at every meeting.
      • If the Iron Brewer repeatedly refuses to defend their title, it will be abdicated.
      • Once a challenge is issued and accepted, any other club members may brew a beer for the competition.
      • Judging will remain hedonistic.
      • The prize remains glory and possession of the sweet Iron Brewer mug.
      • The current Iron Brewer is Will.
  • Ed Topic - Kris

    • Baltibrew Yeast Capture! - Collection of captures
      Many of the captures are showing mold or fungal growth. Fingers crossed that some of the recent captures show more promise.
    • Baltimore’s Water System!!!!
      Look out for a blog post in the Education section summarizing the presentation. The tour of the Ashburton treatment plant is June 21st @ 10AM. Kris will send reminders.
  • Homebrew Swap!


Alternate location for meeting !!!

Due to weather related issues, BaltiBrew’s Monthly meeting will NOT be @ Nepenthe tonight.

Alternate location for meeting, May 17th 2018:


Please enter through the garage, go down the hall to basement door. Meeting in basement. Please be quite, children sleeping.