Tuning In to Water Profiles, Dry Hop Timing and Sparge Water
Q
Most water calculators I have used are based on water profiles of the cities where different beer styles are brewed. Wouldn’t it be a better way to show the water profiles of the beer styles instead of the city water? When I am figuring out which water to use for my beer brewing I get kind of confused as to which ones to use. For example, I would like to see which water profile would be used for a brown ale, which one for a red ale, and the water profile for a stout. We already have that for the OG, IBU, and ABV when we pick a style of beer so why not take it further to show the water profile of each style in the water calculator. Am I missing something here?
Russell Willden
Aurora, Colorado
A
I have never written extensively about brewing water profiles and cannot knowingly comment about why this topic is usually addressed by reviewing the water profiles of historically important brewing centers. But I think I have a pretty good idea why this has been the approach and will answer your question from an assumption about the why. Quite simply, breweries historically brewed beers that worked well with local waters and the topic of brewing water followed this tendency. The fascination and exploration of beer style is a relatively recent development in the history of beer, and part of this process has been reviewing brewing water and trying to determine the best water for a particular style. In fact, the knowledge that we take for granted today about water chemistry is very recent in the history of brewing and goes far beyond the knowledge of most brewers as recently as 60 years ago. Your suggestion totally makes sense and many brewers certainly do approach this topic from the perspective you describe.
A quick review of the water from three major brewing centers that are often referenced in brewing texts (see Table 1 that follows), Burton, Munich, and Pilsen, does provide a good framework for the practical brewer. Without diving down the rabbit hole of water chemistry and the interpretation of water analyses, there are some clear differences that can be seen among these water profiles.
The first major difference is that Munich has a higher residual alkalinity (RA) than Burton or Pilsen. Table 1 expresses RA in °dH (degrees of German hardness); the key thing to know is that water with RA = 10 °dH will increase mash pH by ~0.3 pH units compared to using water with RA = 0 °dH, and water with RA = -10 °dH will decrease mash pH by ~0.3 pH units. RA is a value that considers how calcium and magnesium ions react with malt’s phosphates to lower mash pH as well as how bicarbonate/carbonate ions absorb hydrogen to raise mash pH. Dr. Paul Kolbach published the concept of RA back in 1953 in his paper “Der Einfluss des Brauwassers auf das pH von Würze und Bier” (The Effect of Brewing Waters on the pH of Wort and Beer). Kolbach’s research was very practical in that it related to how breweries could use RA to predict mash and wort pH based on brewing water chemistry. This topic is not simple because mash pH is a result of reactions between malt and water, and both water and malt vary. This is one reason water pH has limited practicality to brewers.
Quite simply, breweries historically brewed beers that worked well with local waters and the topic of brewing water followed this tendency.
In order to make sense of this, it is important to know that the pH of a mash made using pale malt and distilled water typically falls somewhere in the pH 5.6–5.8 range. Although a full malt analysis includes wort pH, it is important to note that the Congress Mash used in the ASBC and EBC methods produces a very dilute wort because the total water-to-malt ratio is 8:1 and the wort gravity is usually about 8 °Plato, which translates to about 1.032 specific gravity. This means that the typical 5.8–6.0 pH range for Congress Wort is higher than a typical brewery mash made using the same malt and distilled water as that used in a malt lab. By the way, the term “congress” used in this context means that the mashing method has been standardized by the brewing industry so that results from various labs are comparable.
Back to the typical analysis and the RA values. If water has RA = 0 °dH, the resulting mash pH will have a pH around 5.75 (A.J. deLange, 2004, “Alkalinity, Hardness, Residual Alkalinity and Malt Phosphate: Factors in the Establishment of Mash pH”). pH 5.6 is at the upper end of where most brewers want to be with mash pH and some sort of acidification is required for water with RA = 0 °dH. When the RA of brewing water is greater than 0 °dH, even more acidification is required, and if the water has RA < ~-7 °dH brewers should be cautious about driving the mash pH too low, especially when using darker specialty malts. Mash acidification can be achieved by using darker malts (for example 10% of 50 °L crystal malt reduces mash pH by ~0.3 units, and 10% roasted malt/barley also reduces mash pH by ~0.3 units) using acidulated malt, adding acids to the mash or brewing water, and/or using an acid rest to increase phosphate levels (which in turn react with calcium and magnesium to lower mash pH).
From a practical view, it is easy to see that Munich, traditionally known for its dark lagers, has water in need of some acid to bring the mash pH down from a predictably high level. The dark malts used for the production of dunkles lagers were the source of the acid used by Munich brewers well before our contemporary understanding of water chemistry was known. Although the water values given for Pilsen and Burton have much lower RA values, the predicted mash pH is still on the high side of the typical upper end accepted by most brewers these days. Burton is known for “pale ale,” but higher kilned malts were, and still are, commonly used in the formulation of these beers. And while Pilsen is the home of the golden lager, the traditional triple decoction mash used for the style does include an acid rest and the mash pHs of historical lagers from Pilsen were probably a good fit for the style; otherwise Josef Groll’s revolutionary pale lager that spread across the globe following its 1842 debut may have been a flop. Imagine being at that beer release . . . wow!
Aside from RA, a composite value calculated from carbonate, calcium, and magnesium levels, the balance of the water analysis from these cities does provide further insight for the practical brewer. Burton water contains notably higher levels of magnesium and sulfate, which are flavor active ions. These ions do contribute to the flavor of beers brewed there. Pilsen and Munich have little in the way of flavor active ions — sulfate, magnesium, chloride, and sodium.
From a practical perspective, it seems that the subject of brewing water is often made more confusing and more difficult to approach because of the ways brewing scientists and techno brewers speak about water. I like to simplify confusing subjects for myself so that I can apply them in everyday life. What follows is the way I think about brewing water and how it relates to style.
Mash & Wort pH
Most beer styles turn out well when the mash pH at 68 °F (20 °C) is between 5.4–5.6, and practical dogma tells me that wort flowing into the kettle should not have a pH greater than 6.0 at 68 °F (20 °C). Mash pH is important because enzymes are affected by pH and so is wort filterability during wort collection. If the mash pH is too low, for example when using high levels of dark malts, the easiest way to raise the pH is by adding baking soda (sodium bicarbonate) because it is soluble at mash pH, whereas calcium carbonate is not. If the pH is too high and the beer style being brewed does not (or should not) contain dark malts, add acid to lower the pH; acidulated malt, lactic acid, and phosphoric acid are the easiest ways to decrease mash pH.
Since mash pH is all about enzymatics and wort filterability, it is totally acceptable and functional to adjust mash pH after mashing in because enzymes are not denatured, or otherwise harmed, by slight changes in mash pH. There is nothing magical about nailing mash pH immediately upon the start of the mash! The reason that commercial brewers want to nail pH at this stage of the game is because commercial breweries are businesses, and in the world of production brewing, time is money. Homebrewers operate by a different set of objectives and adding a bit of time at the start of the mash to tweak the pH is probably not going to ruin a brew day. This does not mean that homebrewers cannot learn from the past and adjust water before mashing, but it is far from a requirement.
Another key point here is that lighter styles, like Pilsner, often benefit from wort pH ~5.2 at the beginning of the boil. The lower pH suppresses color pick-up during wort boiling and is believed to make for a softer bitterness. Wort pH can be adjusted once the kettle is full by adding calcium, lactic acid, or phosphoric acid. Although this technique is well known, it seems that many brewers don’t use it. I consider this a brewing trick because it can make a huge difference in the finished beer by doing something relatively simple!
Remember that mash and wort pH are a function of calcium, magnesium, and carbonate from your water, and phosphates, amino acids, and nucleic acids from malts. The most significant information contained in a water analysis, carbonate, calcium, and magnesium, relates to RA and by extension mash and wort pH.
Water Flavor
All the other “stuff” in water pales in comparison to RA. However, the flavor active ions cannot be overlooked. Sulfate enhances hop bitterness and can add a mineral finish to beers at higher concentrations. Magnesium is bitter and metallic; some beers have a distinctive magnesium flavor and adding magnesium sulfate (Epsom salts) is another trick that can be used to tweak a beer. Both chloride and sodium contribute palate fullness and a sort of sweetness to beer at moderate levels. Although the addition of sodium chloride is not something covered in many brewing textbooks, a healthy pinch of kosher salt (not iodized) can definitely enhance the flavor of many styles.
A couple of extremely important things that you will never see in a water analysis are water flavor and chlorine/chloramine levels. Municipal water supplies are chlorinated and the aroma of bleach or chloramine is easy to detect in most tap waters. Carbon filters are great at removing chlorine and are something that all brewers should use to prevent chlorine from tainting beer flavor. The other non-analytical parameter is flavor. Water can taste funky; musty, algal, sulfur, rusty/metallic, and fishy aromas are not uncommon. If you have funky smelling water, consider using another source. After all, beer is 90% water!
Summary
You are probably not thrilled with this answer because I did not give you what you seek. Quite frankly, I think there are way too many tables that attempt to relate brewing science to beer style. In my brewing opinion, the two topics are more often unrelated than they are related. I’ll give you one example that relates to your question. A great brown ale can be made from water that has a RA = 10 or a RA = -3; the difference is that one brew will probably need a bit of bicarbonate to push the pH back up into the 5.4–5.6 range. A great brown ale can also be made by adding a nice dose of salt to the mash, boil, or beer to enhance fullness and sweetness, and a great brown ale can also be made by adding a nice dose of magnesium sulfate to push the beer into a dry, slightly metallic, and more bitter direction. The pH adjustment is brewing science, but the salt additions are part of the brewer’s art and brewing is a blend of art and science.
Q
When you dry hop, do you typically blow most of the yeast from the fermenting beer before your dry hop doses Or Dry hop On the yeast? Do you buy into biotransformation reactions occurring between hops and yeast?
Wesley Smith
via Live Chat
A
I have dry hopped during fermentation with yeast, blown yeast towards the end of fermentation and dry hopped, have racked beer from one fermenter to another before dry hopping, and have dry hopped beer in the keg. And yes, I do believe that yeast enzymatically change certain hop compounds during fermentation. I like these easy questions!
Digging a bit deeper into biotransformation seems timely as hazy/New England IPAs continue to be a topic of keen interest in the craft beer world. I am really glad that I am not a gambler because I would have lost big time on the longevity of this style, but that’s another story for another day. Research into the ability of yeast to enzymatically change hop monoterpenes has been ongoing for at least 20 years. Brewing and hop chemists have clearly demonstrated that yeast are capable of liberating monoterpenes, primarily citronellol and nerol, from hop glycosides by enzymatic hydrolysis, and have also clearly demonstrated that the hop monoterpenes geraniol and linalool are enzymatically changed, aka biotransformed, during fermentation into other terpene compounds, such as citronellol, citronellyl acetate, geraniol, nerol, and α-terpineol. Similar research has been the focus of enologists (wine folk) since at least the early 1980s, and winemakers commonly use hydrolytic enzymes, such as beta-glycosidase, to liberate terpenes from grapes before fermentation. And like hop terpenes, grape terpenes are biotransformed by yeast during fermentation.
The topic of hop terpene biotransformation is a great example of how science follows practice. Dry hopping was generally uncommon before the growth of craft brewing in the early 1980s, and the very high hopping rates common today among craft brewers was almost unheard of as recently as 15 years ago. Now that more beers are dry hopped at varying rates and at different times in the process, more emphasis has been placed on the empirical results of these practices. Hop research will be very interesting to follow for the foreseeable future as scientists continue learning more about what is really happening as brewers continue to push the boundaries of hopping!
A practical challenge associated with adding piles and piles of hops to the fermenter is beer loss. These losses are largely due to beer absorption by hops and by the relatively low density sediment in tank bottoms that is easily disturbed and moved by beer during racking. New technologies, such as Sierra Nevada’s Torpedo and Mueller’s maxxLup, nicknamed the Odeprot by Anchor Brewing’s Brewmaster Scott Ungermann and featured on a one-off beer called Odeprot IPA, have been developed to dry hop externally. Meanwhile, hop suppliers are continuing to develop new hop products to help deliver hoppiness to beer with reduced plant matter, brewers are improving brewing techniques to drive yield, and brewing scientists are looking at sensory saturation to determine when adding more hops ceases to add more perception. It’s a great time to be a hop lover!
Q
Will sparging at 169 °F (76 °C) instead of a 10-minute mash-out rest at 169 °F (76 °C) achieve the same result and denature my enzymes to lock in my sugar profile?
Luc Johnson
via Live Chat
A
The short answer to this question is no, sparging at 169 °F (76 °C) does not achieve the same thing as mashing out at the same temperature. The reason for this is two-fold. Let’s assume an infusion mash system comprised of 10.4 L (kilograms) water and 4 kilograms of malt (1.25 qts. water per pound of malt) at a temperature of 153 °F (67 °C) is mixed with all 19.6 liters (5.2 gallons) of sparge water at 169 °F (76 °C) required for the brew; assuming no energy from the sparge water is lost to the environment, the resulting mash temperature will be 163 °F (72.6 °C). Not only is this temperature much lower than the typical mash out temperature of 169 °F (76 °C), but this temperature is not possible until all of the sparge water has been added during the course of wort collection. And the reality is that temperature loss to the environment does occur and the mash will never reach the calculated temperature of 163 °F (72.6 °C). Is this significant and relevant to your question? Yes, and it brings up the second point to this answer.
Modern malted barley is an enzymatic powerhouse and the high enzyme level is generally a property of malt that has been very well-modified. Roll back the brewing clock about 25 years and this description of malt would have been believable if the conversation were about North American malted barley; however, malts from continental Europe and the United Kingdom were a bit different, both in terms of modification and enzymatic power, and the same description would not have been a good fit. But in the modern world of brewing, enzymatic power and full modification has become the norm. Why? Because brewers want malts that quickly and reliably perform in the brewhouse with simple mash regimens, and many brewers want malts that can handle enzyme dilution from adjuncts. This means that all-malt brewers need to pay careful attention to these “hot malts” because the high enzyme level and the high degree of modification may result in overly dry beers if the mash is too long.
The normal practice for many commercial craft brewers in the US using the infusion mash method, is to mash-in, quickly begin wort recirculation, aka vorlauf, and begin collecting wort in the kettle as soon as wort clarity is achieved. Since infusion mashing does not employ a mash-out step, enzymes from the mash continue activity in the kettle until the wort temperature is sufficiently high to cause the enzymes to denature. For this reason, it is common for brewers to begin heating their kettles as soon as possible following wort collection. This also reduces the length of the brew day, but that’s just a fortuitous consequence of the main objective. In conclusion, I suggest mashing out if your brewing system allows you to do so easily, or using an abbreviated mash schedule if you want to brew a beer with more residual sugar. And, of course, you can always seek malts that are not so darn hot!