Tag Archives: Science

And the Results are in…

Recently I conducted an experiment on the topic of when to add dark grains to the mash.  Some recommend holding out the dark roasted grains until the very end of the mash.  A number of reasons are given.  One claim is that by holding out the dark grains one does not need to add any bicarbonate salts to the mash to counteract the acidity of the dark grains.  This is a reasonable claim, especially if your water already contains a significant amount of calcium or sodium.  Since the most common bicarbonate salts are calcium and sodium bicarbonate, adding either salt will increase the levels of sodium and/or calcium.  But my water is already low in calcium, and it does not have much sodium either. I am usually looking to increase my calcium levels, so adding calcium bicarbonate to the mash does not bother me one bit.

A second claim I have heard is that allowing these dark roasted grains to mash for an hour is akin to letting a pot of coffee sit on the burner.  After an hour the nice roast flavor will become burnt and harsh.  If that were true, then waiting to add the dark grains would certainly be a no-brainer.

I just finished the last two bottles from the experiment, and I can say I found no taste difference.  As always, your experience may differ, but I plan to continue to mash dark grains as I always have.

Judgement

I started brewing in 1997 and man has the beer landscape changed in 17 years.  Craft beer was around but you had to seek it out – you’d be very lucky to even find a Sam Adams at your local chain restaurant.  Finding respectable samples of many styles was tough – Sierra Nevada Pale Ale was around but the IPA craze had not hit.  Belgians were a rare breed.  If a home brewer chose to make one of these rare styles, then finding a good quality sample of a classic style was not easy.  That made me seek out information about beer judging and due to the internet the Beer Judge Certification Program was a quick find.  It intrigued me.  So much to learn about styles and brewing methods. I knew I wanted to try and become a judge.

It took awhile, but eventually I found my was to an exam and four years ago this January I took the BJCP exam, and even better I passed it. It was a tough test, 3 solid hours of writing and some beer tasting. And today I am a Certified Beer Judge.

But when I look back on why I originally sought out judging information, it was self-doubt.  I made these beers – but were they flawed?  I read about all of these off flavors – diacetyl, oxidation, acetone.  Were they in my beer? Was I missing something?  Well today I worry much less about such things.  I have a little experience and know what I like – and I make beer to drink what I like.  But judging others’ beers is a different thing.  Not only are you charged with finding flaws, you are charged with picking out the best beers.

The reason I mention this is Robert Hodgson. He happens to be a winemaker and a statistician. And he noticed something about the wines he entered into competitions.  Sometimes a particular wine would do very well, other times it would be judged poorly.  So he proposed an experiment to the California State Fair competition in 2005, and he repeated for eight years.  And what he discovered is that wine judges are pretty inconsistent at what they do.  His bottom line: if a wine wins an award it most probably by chance, not merit.

Hodgson was interviewed on the Science for the People podcast. Check it out.  The same episode includes a great interview with Charlie Bamforth, the professor of brewing at Cal-Davis.  If you have never heard Charlie talk beer you are missing a treat.

So science says that my ability to consistently discern the flavor characteristics of a particular beer is quite low.  I can live with that.  I just hope all the brewers whose beers I have judged can live with it too.

Fooling Yourself

When I began homebrewing I was thrilled. I think most homebrewers are. It is a neat feeling to create a wort and turn billions of little critters loose on it. Watch it bubble, bubble, bubble along until finally it finishes. Rush the bottling and wait wait wait until patience be damned and you crack open the first bottle…

And then what? Excitement and pleasure and… doubt. What is that flavor? Is that a bad thing or a good thing? Once I started making beer I started wondering how good or bad my beer was. Friends offer complements, but what do they know?

Reading a description of flavors only goes so far. So eventually I took and passed the BJCP exam and followed that up with some judging experience.  It was all good but I began noticing how different people tasted and judged beers.  Most people are great to judge with.  A few experienced judges have done their best to share insights and make me a better judge.  But a few I found to be bullies.  Very confident in their opinions and dismissive of disagreement.  Frustrating to me.

Steve Novella reviewed a number  of studies that show when it comes to judging alcoholic beverages, experts are just average.  It has been shown time and time again that people are so easily fooled.  Add some red food coloring to a white wine and suddenly the experts will be talking tannins.  Entering into a competition?  Winning is probably highly dependent on luck.  I have been there.  Being the first or last IPA in the bunch can be the kiss of death.

So it all comes back to me and how I like my beers.  I am now confident in my ability to judge my beer, and I while I love to see others enjoy them I don’t seek anyone’s validation.  Will I have beer in the next competition?  Probably.  Will I worry about winning?  Nah.

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More on Stouts and Water Chemistry

I received the November/Decemeber 2013 issue of Zymurgy to find an article by Martin Brungard on Irish water chemistry. His article aligns quite nicely with my recent ramblings on water chemistry and dark beers. Martin’s article reviews the typical rock formations encountered and finds that while Ireland does have a significant amount of limestone (consistent with highly alkaline water) much of Ireland is not limestone geology and therefore softer, less alkaline waters should be found. He presents water analysis data to suggest that the water in Ireland is, by and large, much softer and less alkaline than is often suggested.  The only potential hiccup in this data is that Dublin is in the limestone geology area of Ireland, and one of the rivers that supplies Dublin can have high levels of hardness and alkalinity, depending on the season. The “typical” Dublin water profile is presented (300+ppm of bicarbonate and a residual alkalinity of 170) but it is immediately discounted as being unsuitable for brewing good beer.  So what is the truth about Irish water?

Martin proposes how Irish brewers could get around this.  Boiling of the hard/alkaline water lowers both the calcium and bicarbonate levels of the water. The article suggests that boiling hard Dublin water would result in a water profile very similar to other areas of Ireland.  So if the brewing water is either relatively soft to begin with or boiled to achieve that end, how did Irish brewers use dark roasted grians successfully?  They mashed without the dark roasted grains, and instead cold steeped the roast barley or added at the very end of the mash.

So it is interesting this article popped up just as I was playing around with these techniques.  I am looking forward to trying the beers I made recently using both of those approaches along with the traditional mashing methods.

Going Dark

In the last post I discussed an experiment involving dark beers. I wanted to evaluate three mash methods involving the use of dark roasted grains, and how adding carbonates to the mash water might influence the flavor of the final beer. The recipe I chose was a dry stout, and the grain bill consisted of pale malt, flaked barley and about 12% roasted barley. The home of dry stout is Ireland, and Dublin in particular. Most references suggest that the Dublin water has a carbonate hardness level exceeding 200 ppm, compared to my water that is typically 60 to 70. Note the carbonate hardness does not tell the whole story, residual alkalinity is a better measure as it accounts for the impact of the calcium hardness on mash acidity (the more calcium, the more the pH pf the mash can drop). The RA value for Dublin is often shown to be over 100, up to 125 (the higher the RA, the more it balances the acidity of the dark grain). My RA usually hovers around 30. How much calcium carbonate do I need to add to my mash?

In order to make the best estimate, I surfed on over to the Water Chemistry Calculator at Brewer’s Friend.  This calculator was devised by Kai Troester and based on experiments he conducted on grain color and mash pH. It is a very detailed beast, but if you carefully enter your water chemistry and grist information, then it will nicely calculate your expected mash pH (which should be about 5.5).  And here is where I got my shock: my water was fine as it was, nothing need be added.

How’s that?

Well Kai’s work has shown that dark caramel/crystal grains have much more effect of water pH that dark roasted grains.  In fact if I had used 60 lovibond crystal in lieu of the roasted barley my pH would have been around 5.0, which is far below optimum.  I would love to have confirmed this with a pH meter, but those things are the devil’s work.  They fail more often than first love, and I cannot convince myself to shell out $50 or more on another one of them.

I should note that all of this is controversial.  Some water chemistry calculators work strictly off the expected beer color, and these are ones that, in my experience, tend to suggest some pretty high levels of carbonates.  For instance, John Palmer’s water spreadsheet on his website would recommend an RA of well over 200 for the beer I just made.  While his spreadsheet is quite useful in many ways, that high an RA seems a bit overboard.

Did I mention how easy it is to learn water chemistry?

A Funny Thing Happened on the Way to the Brewery…

Recently I have been pontificating about water chemistry, and I was preparing a post about how I deal with my water when I brew dark beers.  It was all going to center around adjusting the carbonate levels to achieve the correct level of residual alkalinity.  Coincidentally, I had been planning a brewing experiment relating to brewing dark beers, namely, evaluating methods of mashing with dark grains.  It is funny how sometimes reality comes up, slaps you in the face, and proceeds to show you how ignorant you are.
Let’s talk about the experiment.  Mashing involves mixing the crushed grains with water in order to make magic happen, that is, enzymes breaking down long chains of sugar molecules (starch) into little munchy bits that your yeast can gobble up in the process of making ethanol and carbon dioxide. How efficiently this magic happens depends on many things, but the brewer is mostly concerned with the temperature and pH of the mash. Managing temperature is pretty easy, but the pH is a little more complicated, as the grain and the water chemistry both affect the pH. All things being the same (and when does THAT ever happen?), dark grains will tend to lower the pH of the mash. And depending on the nature of your water this may or may not be a problem. Consider Dublin, the home of the classic example of dark beer, the Dry Irish Stout. Dublin water has very high levels of alkalinity, which is to say it reacts with acids in order to prevent the pH from dropping too much. Now where I live the alkalinity of the water is maybe a third or less of Dublin, so in theory if I wish to make a good dark beer I should add something to the water to increase alkalinity. That something is carbonate, either in the form of calcium carbonate (chalk) or sodium bicarbonate (baking soda).
But there is another way. Dark roasted grains do not have any long chains of sugar left to break up, so having them in the mash is somewhat irrelevant. Some brewers choose to not add the dark grains until after the mashing of the base malts is done. Doing this removes the necessity of adding any minerals to your mash, because once the mash is done the pH is largely irrelevant (not to say that the pH of wort and subsequent beer is totally unimportant, but as pH affects mashing enzymes it is).
To take the experiment one step further, some brewers actually cold steep their grains. What is this? Well, you add the dark grains to cold water and let them sit and steep for a longer period of time than a normal mash (overnight?), and then remove the liquid and add it to the wort. Why? well, I have heard the claim that dark grains that are cold steeped have better flavor, such as less harshness.
So I was all prepared to do a three way experiment: brew a dry stout using the “normal” method of adding carbonates to the mash, brew a second adding the dark grains after mashing, and third batch, cold steeping the grains and adding the liquor from that to the wort. And so I set off to demonstrate my knowledge of water chemistry…

My Water – Application #1

In an earlier post, I began discussing my local water and now I am talking about practical examples of how I treat it, depending on the style.

To recap, here is the typical Pittsburgh area water:

Calcium 30 ppm
Magnesium 10 ppm
Sodium 25 ppm
Chloride 30 ppm
Sulfate 75 ppm
Alkalinity 70 ppm

I like this water profile – the levels of all ions are fairly low.  It is easier to add than to take away!  The only potential problem with this water is the calcium level.  The generally recommended level is 50 to 150 ppm, so I am usually adding calcium in one of the three common ways: calcium carbonate, calcium chloride or calcium sulfate.

Recently I brewed a Kolsch-Style Ale – the beer is mostly pilsener malt and just a touch of wheat malt.  Because this recipe has no dark or roasted malts, and my water has low levels of calcium it is quite likely that the mash pH would end up being too high.  Adding calcium should help a bit, and if I add calcium chloride it helps bring up the chloride to sulfate balance.  Why is that important?  Allegedly, beers with a high sulfate to chloride ratio tend to favor hop expression, whereas the reverse brings out the malt.  I have not confirmed this through experiment, but for now I will extend provisional acceptance.

The other thing I did was a about 3% acidulated malt to the mash.  This malt has been kilned in such a way as to encourage the production of lactic acid.  Chew some – it is sour stuff.  Besides helping to drop the pH, adding acid to food generally brightens the flavor.  I think it works well here.

If you are looking for help in figuring out all of the maths I recommend two sources:  John Palmer’s How to Brew website chapter 15-3 has a nice spreadsheet for entering your water data and looking at the effects of various mineral additions.  John’s spreadsheet calculates a target residual alkalinity value based on beer color.  I have read criticism of this method as being unreliable, but in fairness this is all a bit of a guess.  If you are running a production brewery then you are making the same few beers most of the time and you can nail down your water treatment.  As a homebrewer always trying something new you have to make your best estimations

A more advance calculator designed by Kai Troister can be found at the Brewer’s Friend website.  Kai has done a tremendous amount of investigation and experimentation.  His calculator takes into account you entire grain bill (including the types of malts you choose, not just mash color).  His calculator is a thing of beauty, and if you can soldier through the tedium required to enter all of the information, you will be rewarded!

My Water

Many words have been written about water in brewing.  Everything about water is pretty much known, how it behaves in the presence of malt, its impact of chemistry and flavor. Unfortunately water is one of those topics that many brewers struggle to understand. In this post I am going to talk about the local water (Southwest Pennsylvania) and how I approach its modification for brewing.

First I want to give credit to two sources that have taught me about 95% of what I know about water.  The first is John Palmer, whose website How to Brew is a fantastic resource and includes a free, simple, water chemistry spreadsheet.  The second in Kai Troester, whose even more detailed website and blog are full not just of information but experiments he has conducted.  My hats off to both, and thanks for the help.

The first thing about water is knowing what is in your brewing water.  When I became interested in the topic there were not many resources available to learn about the local water supply.  A few years back I called the local water company and found a very helpful person who sent me three or four years of local testing records.  While this was very useful, it was explained that some of the parameters were only tested once per year and for some measurement (sulfate, for example) there was some significant variation. But not having access to better information, I did my best with what I had.

Today, with the growing popularity of brewing, water test kits have become much more available.  A simple one that I use is made by API and is sold for use in keeping aquariums.  This kit is available for less than ten dollars and allows for quickly measuring two important parameters: water hardness and carbonate levels.  These two parameters are key to understanding and predicting your mash pH.  There are kits available which also measure sulfate, and places such as Ward Labs will test a sample of your water for a small fee. If you are a serious home brewer there is not much excuse for not knowing your water.

Here is a breakdown of the typical minerals and ions found it Pittsburgh area water:

Calcium 30 ppm
Magnesium 10 ppm
Sodium 25 ppm
Chloride 30 ppm
Sulfate 75 ppm
Alkalinity 70 ppm

This is really nice brewing water, as most of theses levels are at or below the minimum required (and it is always easier to add the required minerals, versus having to dilute with distilled water in order to reduce concentrations).  The other not so obvious but equally import factor is this water’s low residual alkalinity (in the range of 35).  What the heck is residual alkalinity and why should you care?  Here is my quick and dirty explanation:

For a number of reasons, the ideal mash pH is 5.3 to 5.7.  When water and malt are mixed, chemical reactions occur with the calcium and magnesium in the water. These reactions tend to lower the mash pH (make it more acidic, which is a good thing).  Darker roasted and crystal malts tend to lower the pH more than lightly kilned malts. This tendency to a lower pH is offset by the alkalinity of the water.  The residual alkalinity is the measure of a water’s tendency to lower mash pH.  It is calculated from the water’s calcium, magnesium, and alkalinity levels.  Grain bills with high levels of roasted/crystal malts tend to require water with higher residual alkalinity (RA =100 and up) whereas very pale beers needs a lower residual alkalinity to allow the pH to drop low enough (RA less than 0).

One can see that a RA of 35 is a very happy medium, very suitable for pale ales and other medium colored beers.  Only the most pale beers may require acid malt or an acid addition to bring their pH in line.  Compare this to two other extremes in brewing water: Dublin, the home of stout, has a RA >250.  Pilsen, the Czech home of the pilsner beer has a RA of probably about 10.

If there is a downside to this it is the fact that the mineral levels, especially sulfate, are on the low side for hoppier beer styles.  Note this consideration is only about beer flavor and not about mash pH.  Extract brewers should have low concern about residual alkalinity but should pay attention to sulfate, chloride, and sodium levels. Note that besides pH, the calcium can impact the yeast performance.  At 30 ppm the calcium in my water is a little low, and an extract brewer might still benefit from small calcium additions.

In the next post about water I will provide specific examples of how I went about treating my brewing water.

Travels…

It has been eight weeks of inaction in the brewery.  Several events conspired to gum up the works.  The first thing was bathroom remodeling.  It has been a pleasure to lose two old and outdated baths (one in 1960’s era pink tile).  The down side was my garage was overrun with cabinets and toilets and contractor equipment.  Our contractor is a great guy and an aspiring connoisseur of craft beer.  I turned him on to some of my craft beer (Genesee Ted to the rescue) plus I gave him some Penn Brewery St. Nicholas Bock, as he had mentioned how much he liked a local brew pub’s Munich Dunkel.  All beers were a hit with him.  Nice to see.

The second event that closed the brewery was our annual spring holiday vacation, this time taking us to see family in Arkansas.  It was nice to get away, although the weather in Arkansas started cold and miserable (much like the rest of the country in late March).  Besides family we visited the William Jefferson Clinton presidential museum in Little Rock.  I had forgotten how much Clinton did for this country.  Jobs were created and the economy grew.  A 260 billion dollar budget deficit ended up as a budget surplus.  Then we turned it all over to the Tweedle Dee from Texas and the country has not recovered yet.

One big plus was the chance to pick up a few beers that I don’t normally see locally.  Two bottled of La Folie, check.  Uerige Sticke and Doppelsticke.  Jolly Pumpkin Bam Biere.  Barrel aged Old Rasputin and Ommegang Art of Darkness.  And a couple of others.  I guess not brewing has its advantages.

Last weekend was the best, though.  I traveled to New York City for the Northeast Conference on Science and Skepticism (NECSS).  Hard to believe this was the first time I set foot on Manhattan.  But I am going back.  It is a crazy, fun place. The conference itself focused on topics relating to many aspects of science and skepticism, from atheism to scientific skepticism, from brain function to the big bang.  I used Megabus to get to New York ($90 round trip).  It worked well, although their Wi-fi is about useless.  It dropped me off right in midtown Manhattan, right where NECSS was held.  Coming back I took a “red-eye”, leaving NYC at 10:45 pm and arriving back around 6:30 am. That return was probably a mistake.  Staying up most the night was easy when I was in college…

But it is time to think about brewing again, stay tuned.