written by Vincent Feminella
Every successful brew day begins with a well-thought-out plan based on a recipe using the perfect combination of grains, hops, yeast and the brewer’s preferred brewing process. Of course, the goal of every brew day is to brew the best tasting style of beer possible, and to brew it as consistently as possible each and every time. While brewing the same recipe using the same grain, hop, and yeast selections time and time again is easy to do, that doesn’t guarantee there won’t be differences in the finished batches due to other variables. We know that variations in mash time, thickness, and temperature change the fermentability of our wort and how differences in sparging will change pre-boil, and ultimately post-boil, volumes and wort gravity. The length of the boil and the timing of hop additions are other variables we control to influence the taste of the finished beer, along with the addition of kettle finings to make the wort clearer. Other variables include the length of time it takes to bring the boiling wort down to pitching temperature, yeast viability, cell count, pitching rate and fermentation temperature are also important variables the brewer controls to influence the taste of their finished beer. Beer can’t be served until it’s been conditioned and packaged using any one or all of several different methods like transferring to a secondary, cold crashing or filtering before kegging or bottling. Variations in the conditioning, packaging and storage process also influence a beer’s flavor—they are the final variables that the brewer has control over in the life cycle of a batch of beer.
Brewers know it takes years of study combined with a lot of time spent brewing to understand all the variables there are in making beer, and even more time learning how to control those variables in order to produce consistently good beer. With so many variables available to tune and tweak their beer flavor, it’s not surprising that most brewers brew the best beer possible for years before deciding to understand their brewing water. Brewing water is the single largest ingredient by volume in any beer recipe and it is the foundation for many different styles of beer. By now, we’ve all read or heard about the relationship of the water in a region to a particular style of beer. For instance, Dublin’s hard water makes a great tasting stout, Burton’s gypsum rich water is great for making pale ale and Pilsen’s soft water makes a really good pale lager. The brewer should also understand that all regions experience seasonal changes in their water properties and to some extent, yearly changes too. For example, one notable case was last year’s Sonoma County drought that prompted the Lagunitas Brewing Company to inform their customers that the river water supply that gives their beer its unique signature taste may have to be replaced with reverse osmosis filtered water from another source. That’s a clear example of how much brewers rely on a consistent supply of water in order to eliminate variations that change the taste and quality of their finished beer.
There are basically two approaches to maintaining brewing water consistency year after year and from season to season. If you have the resources needed to check your water source for alkalinity, pH, salt and mineral levels and are able to adjust them as needed to match a specific brewing water profile, consider yourself among the most fortunate of home brewers. Since the source water properties can vary greatly over time, the adjustments needed to bring them in line with a specific water profile will need to be adjusted too, in order to compensate for these changes. Or instead, you could use a consistent water source like distilled or reverse osmosis water and adjust the pH levels up with baking soda or down with lactic acid until they are in range of your targeted brewing water profile. This is much easier to do because the water source properties remain consistent over time and in turn, so will the amounts of baking soda or lactic acid needed to adjust the brewing water pH levels to a targeted range. The same holds true for the salt and mineral additions, they would always remain constant since distilled or reverse osmosis water removes all traces of salt and minerals. Once you figure out the amounts of acid, base, salt and minerals that make the best tasting beer, you simply write them down for next time, knowing that future water property adjustments will remain the same time and time again.
So where can a brewer interested in understanding and adjusting their brewing water properties begin? If you’re not already filtering your brewing water, now is a good time to start. Running your brewing water through a sediment filter and a carbon block filter will greatly reduce the amount of particulates and many other contaminants, including chlorine and chloramines, which in sufficient amounts have a dulling effect on beer flavor and taste. With a minimum investment you can install a carbon block filter brew a favorite recipe using filtered brewing water and compare the taste and flavor of the beer to prior batches using unfiltered water. Depending on where you live and the hardness of your water source, you may notice that darker colored beers like stouts, porters and browns taste more flavorful, or maybe your lighter colored beers like wheats, pilsners and pale ales taste better. In either of these scenarios you can take an educated guess on the hardness of your water, if your darker beers taste better, you most likely have harder water; if your lighter beers taste better, you most likely have softer water. This is a high-level observation that can be made without understanding all the underlying chemistry behind what makes water hard or soft. When evaluating water hardness, we’re really looking at the amount of calcium and magnesium in the water. The more calcium and magnesium in the water, the harder the water is, and the less calcium and magnesium in the water, the softer the water is. Brewing water with just the right ratio of magnesium to calcium will promote increased wort fermentability and ideal yeast fermentation characteristics including higher attenuation rates and increased cell viability.
“Buffers, moles, ions, cations, anions, acid, base, atomic weights, valence, electrons, Lewis structures, central atoms, bonding sites, mg/L as CaCO3, mg/L, ppm, milliliters, teaspoons. Really? Let me just arrange all that information in a way that’s interesting and understandable by the majority of brewers…” ~ Screwy Brewer
Knowing the differences between hard and soft water measured by the concentration of calcium and magnesium in your brewing water and the styles of beer that will benefit when brewed with harder or softer water gives you the opportunity to brew a more flavorful beer. Eliminating chlorine or chloramine from your brewing water will eliminate the dulling effects they have on your finished beer while improving the beer’s flavor and taste even more. Knowing the hardness of your brewing water and which style of beer tastes better when brewed with it and then filtering that brewing water through a carbon block filter are two easy ways brewers can greatly improve the quality of their beer without a whole lot of effort. Getting the maximum benefits from all grain brewing also depends on two other very important properties of our brewing water—alkalinity and pH levels. Brewing water alkalinity is a buffer that we build into our water profile to resist changes in pH levels that happen when the acid from darker grains tries to lower the pH level or when base from the potassium produced during the mash tries to raise the pH level. An example of how alkalinity, or buffering, maintains a specific pH range when acid is introduced can be thought of like this, “…the human body naturally maintains an internal pH range of 7.3 to 7.4 and a typical beer has a much lower pH level measuring in the 4.0 to 4.5 range, but when we drink several beers, our internal pH level stays within the same healthy 7.3 to 7.4 range…” Our body has a very strong buffer, or high alkalinity level, that has been programmed to maintain the optimal 7.3 to 7.4 pH range that keeps our cells and us alive. Examples of a weak buffer or low levels of alkalinity in water are distilled, reverse osmosis [RO] and deionized [DI] water that through the distillation or filtering process have had their salts and minerals removed, leaving the water with very low alkalinity and stripped of any buffering power. Very small additions of acid will lower the pH level and very small additions of base will raise the pH level of water when it’s in this state because it lacks any strong buffering needed to resist those changes.
The optimum pH range for mashing grains is between pH 5.4 to 5.6 when measured at 77˚F [25˚C]. When making brewing water pH adjustments, the goal is to also build in buffering, or the alkalinity level, that is strongest within this targeted pH 5.4 to 5.6 range. The reason for buffering brewing water in this range is to counteract the rise in pH level caused by the potassium produced during the mash. Potassium is produced throughout the mash as grains soak in the hot mash water, resulting in a mash pH level higher than the optimal pH range, unless the brewing water pH and alkalinity levels have been adjusted to counteract the rise. The addition of calcium to the brewing water neutralizes the rise in pH level caused by the buildup of potassium in the mash and lowers the pH level so it stays within the optimal pH 5.4 to 5.6 range. When we talk about adjusting the pH of brewing water to target a specific pH range we also have to adjust the alkalinity of the brewing water so it’s buffering is the strongest within that pH range. With low alkalinity levels and weak buffering, any adjustments made to the pH of a brewing water profile will be easily changed once the water comes into contact with the grains during the mash. Temperature also has an influence on brewing water and mash pH measurements in a not so obvious way. While the warmer 148-158˚F [64-70˚C] mash temperatures drive off the acidic carbon dioxide, which in effect raises the pH level, readings taken at the higher temperatures interfere with the response of a digital pH meter resulting in readings that average 0.2 points lower than when taken at room temperature. In order to get the most accurate pH readings the sampled liquid should always be at or a few degrees above average room temperature.
We know that mashing at the lower end of the recommended mash temperature range of 148-158˚F [64-70˚C] produces a more fermentable wort and a thinner bodied beer, what isn’t so obvious is that the same thing happens when the mash pH is held at the lower end of the 5.4 to 5.6 pH range. Mashing at the lower end of the recommended pH range not only increases conversion efficiency, it also reduces chill haze, enhances hot break, beer color, and taste while reducing harsh bitterness in the beer. Keeping the mash pH within range also eliminates any risk of introducing tannins or other harsh flavor components into the finished beer and improves the rate of diacetyl reduction during conditioning. It also promotes more efficient conversion of starch into sugars and the development of insoluble phosphates that precipitate into the grain bed, increasing its filtering capacity and making the wort passing through it extremely clear and bright. There are so many ways that a beer benefits from being brewed with a water profile designed specifically for a certain style of beer that it’s almost unbelievable. In the past, most home brewers never advanced their brewing skills to a level where they started taking a closer look at their brewing water. Back then, information about brewing water properties was pretty scarce and what was available was enough to cause the eyes of even the most passionate brewers to glaze over and quickly lose interest in the subject. Fortunately, in recent years, more brewing water information has been made available to home brewers than ever before and it’s written in a way that’s easily understood by non-chemistry majors. Understanding the chemistry happening behind the scenes will enable you to look at a standing glass of water and imagine how the frenzied hydrogen and hydroxyl ions are constantly being split apart only to combine again into new water molecules. You don’t have to understand all of the water chemistry involved to brew great tasting beer, as long as you understand what’s in the brewing water you plan to use and what changes need to be made to it.
Using local tap or well water means starting with seasonal differences in the source of water that can only be measured accurately after having the water analyzed and then recalculating the water property adjustments needed to recreate a favorite water profile. Once you know the properties of your source water you’ll need to plug them into a tool like EZWaterCalculator in order to calculate the adjustments that will be needed to bring the source water into range of your favorite water profile. When using tap or well water, your water report should provide the parts per million of calcium, magnesium, sodium, chloride and sulfate to plug into the calculator to get started. You also enter the total volume of brewing water you need and the percentage of that brewing water volume that will be made up of distilled or reverse osmosis water. After entering the type and amounts of grain in your recipe, the calculator will begin to display the pH, alkalinity and mineral levels of the water profile. Using readily available ingredients like 88% lactic acid or Acidulated malt you then start adjusting the water profile pH level to be within the 5.4 to 5.6 range adding in gypsum, calcium chloride and Epsom salt to increase the alkalinity level to match the style of beer and add ‘flavor’ to the brewing water. The calculator is smart enough to display the pH level in green when it’s within the recommended range and in red when the values fall outside of the range, making it very easy and safe to use. The calculated salt and mineral additions also display in green when they’re within the recommended range and red when they have gone outside of the range. A built-in chloride to sulfate ratio display provides feedback on whether the water profile is better suited for brewing a malty or a bitter beer. EZWaterCalculator is a great water profile tool to use because it is easy to understand, uses easy to find ingredients and it lets you do an infinite number of ‘what if’ calculations to determine just what water property adjustments are needed to brew a perfect beer every time.