Wednesday, March 23, 2011
Tuesday, March 22, 2011
Friday, March 18, 2011
Wednesday, March 16, 2011
Now that you've removed most of the alkalinity from all of your water, it's time to treat the mash water to hit a target pH. Let's start by estimating your distilled water mash pH. Based on more of my mash experiments, trends from Kai Troester's website and product specifications from Weyermann Specialty Malts, you can assume the following:
-Roasted malts will lower mash pH by 0.028 for each 1% they comprise of the total grainbill.
-Acidulated malts will lower mash pH by 0.1 for each 1% they comprise of the total grainbill.
-Pale malted wheat will raise mash pH by 0.003 for each 1% it comprises of the total grainbill.
-All other malts will lower mash pH by 0.00027 per degree Lovibond in excess of Pilsner malt for each 1% they comprise of the total grainbill.
-Pilsner malt has an average color of 1.8 degrees Lovibond.
-Decoction mashing will lower mash pH by about 0.1.
If you want to brew a beer with 9 lbs 6 oz of pale ale malt (3L), 8 oz of caramel 60L and 2 oz of chocolate malt (10 lbs total), the pH drops from each grain can be estimated as follows:
pH Drop, Pale Ale Malt = 0.00027 x (3 - 1.8) x (100 x (9 + 6/16)/10) = 0.03
pH Drop, Caramel 60L = 0.00027 x (60 - 1.8) x (100 x (8/16)/10) = 0.079
pH Drop, Chocolate Malt = 0.028 x (100 x (2/16)/10) = 0.035
Using 5.65 as your distilled water mash pH for Pilsner malt, the distilled water mash pH for your grainbill will be 5.65 - 0.03 - 0.079 - 0.035 = 5.51. If your target pH is 5.4, you wouldn't have very far to go if the residual alkalinity of your water was near zero. Unfortunately, that's not the case for Madison city water.
Remember Kohlbach's formula for how residual alkalinity affects wort pH, and how the 0.084 number would have to change for mashes of varying thickness? To figure out the replacement multipliers, I manipulated the data from Kai's mash pH experiments and created the following chart:
It would be possible to create a two-variable equation to calculate the pH shift from a given residual alkalinity and water-to-grist ratio, but a more elegant solution is to plot the pH shifts against total mEq of residual alkalinity per pound of grist:
That nice linear relationship means that each mEq of alkalinity will result in a constant pH increase per pound of grain. The same value will apply to each mEq of acidity as well, but the shift will be in the opposite direction. The pH shift, determined in an experiment I performed at home, is 0.059 per mEq of acid per pound of grain. If you accept my experiment as the gospel truth, you can determine your target residual alkalinity with the following equation:
Target RA = (Target pH - pHd) x Grist Weight / 0.059 / Mash Water Volume + 0.05
In the equation, pHd is the distilled water mash pH for a given grainbill, grist weight is in lbs, and mash water volume is in liters. If your mash water volume is 14.2 L, your target residual alkalinity will be (5.4 - 5.51) x 10 / 0.059 / 14.2 + 0.05 = -1.263 mEq/L.
Now that you know the target RA of your mash water, let's assume you're starting with the lime-treated water from Part IV:
Calcium = 3.302 mEq/L
Magnesium = 3.702 mEq/L
Chloride = 158 mg/L
Sulfate = 95 mg/L
Total Alkalinity = 1 mEq/L
RA = 1 - 3.302/3.5 - 3.702/7 = -0.472
Calculating the acidity required to lower your mash pH is similar to the previous calculation for total water volume:
Required Acidity = Water RA - Target RA = -0.472 - -1.263 = 0.791 mEq/L
Because the pH of your mash will be lower than the pH of your sparge water, a smaller percentage of lactic acid molecules will dissociate in your mash. Here's how to estimate what will happen:
Dissociation = 100 x (1 - 1 / (1 + 10^(Target Mash pH - 3.83))) = 100 x (1 - 1 / (1 + 10^(5.4 - 3.83))) = 97.4%
...here's how to calculate how much acidity your lactic acid will contribute to your mash:
Acidity = 1000 x (Acid Strength / 100) x (Dissociation / 100) / 90.09 / ((Acid Strength / 100) / 1.2+(1 - Acid Strength / 100)) = 1000 x (88 / 100) x (97.4 / 100) / 90.09 / ((88 / 100) / 1.2+(1 - 88 / 100)) = 11.149 mEq/L
...and here's how to determine your required volume of lactic acid:
Lactic Acid = Required Acidity x Water Volume / 11.722 = 0.791 x 14.2 / 11.149 = 1.0 mL
If you need to raise the alkalinity of your mash water, here's an equation that will tell you how much calcium carbonate to add in grams:
CaCO3 = (Target RA - Water RA) x Water Volume / 14.27
If your target RA is 0.5 mEq/L, you'll want to add (0.5 - -0.472) x 14.2 / 14.27 = 1 g of calcium carbonate. I'd add it directly to your mash because it won't dissolve in non-acidified water. That said, Kai's experiments suggest that mash additions are only effective when the total alkalinity of the water (after adding CaCO3) is around 5 mEq/L or less. You should never need that much alkalinity, so don't lose sleep over the solubility of calcium carbonate.
That brings us to the end of this series on water chemistry. Whether you crunch the numbers or use the simplified treatments from Part II, you should be rewarded with improved brewhouse efficiencies and cleaner-tasting beer. If you'd like to use the detailed calculations but don't want to do the math every time you brew, my water treatment spreadsheet (located here) will do the work for you. The file name is Water_Gallons.xlsx, and the same calculations are embedded in the Recipe_Gallons.xlsx file. You can return to the beginning of this series here.
Monday, March 14, 2011
Friday, March 11, 2011
Monday, March 7, 2011
My friend and I had a bit of a narrow miss here, leaving Christchurch just two hours before the earthquake hit. Our intention was to visit Pomeroy's Old Brewery Inn that day, but the brewpub is closed for lunch during the week so we decided to move on. Poor planning on my part that ended up being a lucky fortune! (Though I'm still a bit crabby that I didn't get to sample any of their beers.)
We did get to visit two Christchurch breweries the day before the quake though: Dux de Lux and the Twisted Hop. Both get a thumbs up from me! Great atmospheres, great beers and great staff at both. We really had a good time.
Dux de Lux was our first stop upon arriving in Christchurch. It was a beautiful day and they have a lovely outdoor patio. I got the full flight and enjoyed everything but the Ginger Tom, which is an alcoholic ginger beer. You REALLY have to like ginger in order to enjoy this beer. It was way too much for me, but my friend loved it (in fact, it launched a trip-long hunt for the country's best ginger beer). My favorites were the Hereford Bitter and the Black Shag. The Hereford bitter is something of a cross between a standard English bitter and an Oktoberfest- malt forward with nice caramel notes, a nutty aroma and a subtle hop finish. The stout was poured on nitro, so it was nice and creamy (which I love!), pretty sweet for a stout (leaning towards a milk stout) with a roasty after taste and maybe some very subtle licorice flavors.
Later that night we headed over to the Twisted Hop, which focuses almost entirely on real ales. Yay! The Twisted Hop was terribly charming: it's situated in an area of town with very narrow lanes and beautiful old brick buildings, many of which are sadly gone now. Again, I ordered the flight here. Surprisingly, I think my favorite was the Improvisation Pale Ale- citrusy, with orange and lemon flavors, this is definitely an English-style pale ale, which I enjoy much more that the hopped-up American versions. Of course, I should say that was my favorite until I got to the Nokabollokov Imperial Stout and the Enigma Barley Wine.... The Nokabollokov is all roast and burnt chocolate, and velvety smooth. The burnt flavor is not overwhelming or offensive at all: it complimented the chocolate in the beer nicely, like char on a grilled hamburger. I really enjoyed this one.
The Enigma Barley Wine was all dark fruits, raisins and molasses, with a surprising spritz of citrus underneath and a slightly hoppy finish. My only criticism is that you definitely get that alcohol bite at the end. The Twisted Hop came through pretty well in the earthquake from what I've heard (and relative to the buildings around it)- John, the brewer at Arrow Brewing, told us that they had an engineer in after the last quake to tell them what building improvements they needed to make, which was all a huge pain in the behind apparently (along with being wicked expensive), but clearly paid off in the end! Here are some before and afters of the Twisted Hop (the after shots courtesy of the Twisted Hop website):
After news of the quake came out, we were all anxious to hear how our brewer friends fared (along with everyone else, of course). The Society of Beer Advocates posted some updates for us in the days following: (Note: I've shortened this update from SOBA to just the breweries in and around Christchurch. Additional updates on local beer bars and liquor stores can be found in the full text here.)
I'm sure we're all far too busy worrying about our friends and loved ones in Christchurch to be thinking much about beer right now, but for many of us, the wonderful brewers, publicans, and SOBA people in Christchurch *are* our friends.
For those not glued to twitter, here are some updates to hand. Note that I'll not be spreading any rumours here, this is just what is known by those involved or tweeted by trusted friends.
The Twisted Hop: Martin and Sean are both safe, and the pub is still standing (just) - remarkable!
Pomeroys: Not so lucky, the building is trashed, but the people are OK and that's always the important point. Update from Robyn (via Twitter): power and water have now both been restored. Hurrah!
Three Boys: Ralph is alive, well, and reporting in his own inimitable style that the brewery is "fucked".
Cassels and Sons: Nigel is tweeting that the brewery is in a bad way, and he'll be down for some time, but at least he is tweeting! Update from Robyn: we've also had a video update from Cassels.
Dux de Lux is in bad shape but fixable, and Dick is OK. He also says Matsons looks OK, confirmed by David Wood who tweeted that they even finished a brew during the quake!
I've just had a call from ex-Golden Ticketer, and now Harringtons employee Nathan Crabbe. Nathan is safe and sound in Twizel, but has heard from Mark at Harringtons that all are safe, but the brewery is in a bad way.
Andrew Madden from Lion Nathan confirmed that all staff were OK, but the Canterbury brewery took more damage to add to the battering it received in September.
Geoff Griggs tells me that Paul McGurk at Wigram is OK and the brewery has sustained only minor damage.
I also saw that McCashin's Brewery in Nelson is donating space and equipment for brewing and bottling, as well as ingredients to any breweries put out of commission by the earthquake, which I think is very cool. I've heard that a few other breweries have offered the same, but I can't confirm who. If you'd like to donate to the recovery efforts in Christchurch, you can do so through the New Zealand Red Cross. I'm sure moral support via Twitter, Facebook and email would be welcome too!
Tuesday, March 1, 2011
Summary: Looking big-picture, it is fairly typical of quality Midwest DIPAs in that it balances the considerable hoppiness with a prodigious amount of malts - in this case not a ton of specialty malts though, which keeps that maltiness, though not the sweetness, at a minimum; Midwestern hop-heads will love this beer, West Coasters wouldn't be sure what to do with it - it's not nearly as "over-the-top" as the 100+ IBU monsters from out there, but it's certainly bigger than their standard IPAs; my own tastes are well-documented in these pages; but, overall, a very solid DIPA.