Author: Malcolm Frazer

Not all chemicals are bad. Without chemicals such as hydrogen and oxygen,

for example, there would be no way to make water, a vital ingredient in beer.

~Dave Barry~

This is a follow-up to the first water chemistry xBmt where 2 batches of the same German Pilsner, each mashed with water profiles consisting of different mineral and pH levels, were distinguishable by a significant portion of participants. As a lover of all things H 2 O, I was excited to return to this topic! I’ve delved rather deeply into the subject and learned a ton from noted experts such as John Palmer, Colin Kaminski, Martin Brungard, Kai Troester, and of course, the guy they all quote, AJ Delange. Since the beginning, I’ve truly believed water matters in brewing– how could it not when it makes up nearly 90% of the beer we drink? Plus, chemistry is fun and really works wonders as a first date conversation topic!

It is generally accepted that higher amounts of sulfate (SO4) will lead to a crisper, drier finish that accentuates hop bitterness and bite, while increased chloride levels produce a smoother, rounder finish with accentuated malt expression and perhaps more perceived sweetness. While I believe my own private experience is inline with this, I’ve never actually blindly compared 2 beers of the same recipe mashed with water consisting of different mineral levels, which means by belief is really based on assumptions, things I’ve read, and information relayed by others. Given the fact my first encounter with Marshall occurred when he happened upon an instance of me rebuking some brewing dogma in an online forum, how could I justify my self-confirming bias towards water’s impact without putting my assertions to the test?

| PURPOSE |

To evaluate the effect different mineral additions have on 2 beers of the same recipe. Two separate batches of the same Dry Irish Stout were produced simultaneously, one was brewed with water that was adjusted in a manner that would be typical of a dark malty beer, while the other was brewed with a water that was adjusted in a manner typical for a hoppy pale ale.

| METHOD |

A similar experiment performed by John Palmer at the 2007 National Homebrewers Conference supported the notion that manipulation of water chemistry made a noticeable difference between similar beers produced with and without brewing liquor adjustments. Inspired by these results, I designed an xBmt with a few differences, namely that data would be collected using a blind triangle test rather than a side-by-side comparison. Furthermore, rather than creating water profiles with different mineral makeups and pH levels, similar to Marshall’s prior xBmt, I was interested in isolating the effects of mineral additions alone, thus acid was used only to bring each mash to a similar pH. My intent was to pick water profiles at the opposite ends of the spectrum in order to emphasize the organoleptic qualities that are believed to be brought about by differences in certain mineral levels.

Dry Irish Stout Recipe

Batch Size Boil Time IBU SRM OG FG ABV 5.5 gal 70 min 39 35 1.045 1.010 4.75 %

Fermentables

Name Amount % Maris Otter 6 lbs 67% Flaked Barley 2 lbs 22% Roasted Barley (550L) 1 lbs 11%

Hops

Name Amt/IBU Time Use Form Alpha % East Kent Goldings ~39 IBU 60 min Boil Pellet 5.0%

Yeast

Name Lab Attenuation Ferm Temp WLP004 Irish Ale Yeast White Labs 69-74% 66°F

Separate mashes were required for this xBmt since that’s where manipulation of the variable was to occur. I carefully measured the grains, ensuring both batches received precisely the same amounts, and did some milling.

I chose to utilize the batch sparge method and used Bru’n Water in conjunction with BeerSmith to determine mineral and acid additions for each batch. While the differences between Pale Hoppy and Dark Malty water profiles in Bru’n Water are relatively drastic, I focused solely on the sulfate (SO4) to chloride (Cl) ratio, keeping total ion levels moderate and using only a single salt for each mash– CaSO4 (Calcium Sulfate or Gypsum) for the Pale Hoppy water batch and CaCl2 (Calcium Chloride) for the Dark Malty water batch.

My municipal tap water is fairly well suited for Pale Ale in terms of natural mineral content, requiring only minimal acidification for alkalinity reduction and a small addition of gypsum (~2 grams) to achieve my preferred SO4:Cl of ~2:1.

I’ve found a mash pH of 5.4 works well for many styles and settled on that as my target for these beers. It took the addition of an extra 0.8 ml of lactic acid over what Bru’n Water predicted to reduce the pale hoppy water mash to 5.41 pH.

Pale Hoppy Water Profile

Ca Mg Na SO 4 Cl HCO 3 SO4:Cl 90 16 36 167 67 149 2.5

Since my goal was to keep the relative magnitude of each mineral approximately the same between the batches, I diluted my municipal source with 30% distilled water so I wouldn’t have to add high amounts of CaCl 2 to reach my desired ratios. To this tap/distilled blend I added 2.2 grams of CaCl 2 and 0.5 ml of 88% lactic acid, which resulted in a SO4:Cl ratio of .44 and a mash pH of 5.37, close enough to my 5.4 pH target.

Dark Malty Water Profile

Ca Mg Na SO 4 Cl HCO 3 SO4:Cl 82 11 25 55 123 86 .44

It was time to mash! I staggered the start of each batch by 15 minutes in hopes of making the brew day less hectic.

Oddly, I came in a bit low on my mash temp for the first batch, hitting 145°F instead of my planned 151°F. This was easily remedied by using my handy bucket water heat stick to raise the temp in a matter of just a few minutes. In order to maintain consistency between the batches, I heated the second batch of strike water to the same temp as the first, achieving the same initial mash temp, then used my heat stick to bring the temp up.

Both pre-boil gravities were slightly lower than BeerSmith’s predicted 1.034 SG, with the Dark Malty profile batch hitting 1.032 and the Pale Hoppy profile wort clocking in at 1.030. I wondered if having false bottoms from different manufacturers or the use of the heatstick inserted some variables. Both worts were boiled for 70 minutes, 10 more than planned to make-up for the lower pre-boil SG, receiving a single dose of EKG at the 60 minute mark and a tab of Whirlfloc with 15 minutes left.

Post-boil hydrometer measurements revealed a .001 SG difference between the batches, with the Dark Malty profile wort at 1.047 SG and the Pale Hoppy profile wort at 1.048 SG.

The worts were chilled, transferred to 6 gallon Better Bottle carboys, and hit with oxygen for 90 secs, after which I placed them in my fermentation chamber and pitched 1L of WLP004 starter into each.

Both beers reached target FG of 1.010 after 6 days of fermentation.

A few more days in the chamber and the beers were transferred to kegs where they were chilled then fined with gelatin. They were ready for sampling a few days later.

| RESULTS |

I am massively grateful for the support I received from the homebrew and craft beer community when I sought participants for this xBmt, the turnout was incredible, with local breweries and restaurants graciously allowing me to host the tasting sessions at their establishments.

In addition to all the local support, James Spencer and Steve Wilkes of Basic Brewing Radio also participated.

A diverse assortment of 29 participants lent their senses to this xBmt including Certified and National BJPC Judges, BJCP judges in training, a few professional brewers, a craft beer restaurant owner, some die-hard beer geeks, impassioned homebrewers, and even a couple casual beer drinkers. Each taster was blindly presented with 1 sample from the Dark Malty profile batch and 2 samples from the Pale Hoppy profile batch and then asked to identify the beer that was different. At the given sample size, 14 (p<0.05) tasters would have had to accurately select the different beer to reach statistical significance. In this case, 18 (p=0.001) participants correctly identified the beer that was different. From this, we can deduce that the participants’ ability to distinguish between the 2 different beers is most likely not due to random chance, but rather a function of the differences in mineral content of each batch’s brewing liquor.

Side-note: we recently revamped the survey in hopes of collecting more interesting data. One of the biggest changes involves revealing the nature of the xBmt to those who are incorrect on the initial triangle test then allowing them a second chance, the purpose being to gauge whether knowledge of the independent variable has an impact on perception. This data will not be combined with data from the initial triangle test! We also ditched the comparative evaluation, as we found that data to be largely subjective and inconsistent.

Those participants who were correct on the first triangle test were then asked to select the beer they preferred. Interestingly, there was no clear preference, which goes to show that while water certainly seems to make a difference, how that difference is perceived is still subjective.

Once the nature of the xBmt was revealed to those who were initially incorrect, only a single participant changed their selection to the correct answer, not nearly enough to suggest knowledge of the variable significantly impacted perception.

There appeared to be some agreement among participants regarding perception of the Pale Hoppy profile beer as more roasty and bitter than the Dark Malty profile beer, which was perceived by a few tasters as being sweeter with a more noticeable ester profile. Please bear in mind this data is not conclusive and based on the responses of only those who clearly identified the sample they were referring to when commenting.

My Impressions: I have no doubt my involvement in the process tainted my ability to approach tasting from an unbiased perspective. For one, I was aware of the nature of the xBmt and hence knew what differences to look for. Also, being involved with the beer throughout the process, tasting and sampling along the way, is akin to asking a mum to tell her own twins apart. A few panel members wondered if I’d be able to tell the difference if served semi-blind; when I assured them I could, I was put on the hot-seat. In each of these 3 separate trials, I was able to correctly identify the different beer, twice based on aroma alone. So yeah, to me, the beers were absolutely different, especially as they warmed. Prior to packaging, I perceived the Pale Hoppy profile beer as almost soapy and harsh in comparison to the nearly porter-like Dark Malty profile beer. However, after the beers were fined with gelatin and given some time in the keg, the delta decreased and each became enjoyable in its own right. The Pale Hoppy profile beer was unidimensional, mostly roasty with only hints of what I feel a stout should be. Still, I enjoyed how easy this beer was to drink, it finished clean with a snappy hop finish. To me, the Dark Malty profile beer was well layered, almost as if the malt bill was more complex than I knew it to be. I picked up notes of chocolate, smooth roast, light cinnamon coffee, low caramel, and a fuller body. Despite finishing at the same SG as the Pale Hoppy profile beer, the Dark Malty profile beer lingered on the finish and felt thicker with more perceived sweetness. Which one do I reach for most often? Both! I like to blend them.

| DISCUSSION |

Chalk another one up for water chemistry! As we continue down this path of homebrew experimentation, I’m left wondering about the recommendation I’ve heard many times that homebrewers should make water their last focus, especially since making adjustments is so easy. Despite my predilection for water chemistry and belief it makes a difference, I’m not yet prepared to claim water is more important or has a greater impact than any other aspect of brewing, ingredients or otherwise. But goodness, with the fact both water chemistry xBmts have produced statistically significant results, I’m comfortable claiming it’s at least as important! Beer is mostly water, after all, perhaps it is worthy of more attention than many of us have given it.

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