Brett Sour (3/9/14)

My latest sour beer uses the same quick-souring technique as my last two sours, sometimes known as sour-worting (a variation on sour-mashing). I mash the beer normally, but rather than boiling the wort after mashing, I cool it to 112˚F, add 1/4 lb of crushed 2-row barley, and maintain that temperature for 3-7 days. During this time, the native lactobacillus present on the barley produce lactic acid. The temperature inhibits the growth of spoilage bacteria and yeasts. After souring, I boil the beer normally, with a modicum of hops. The boil kills virtually all bacteria, so from this point onwards, the beer is no longer spontaneously fermented. I pitch a pure-culture strain of yeast and ferment according to that yeast's needs.

The only tricky part about this whole shuffle is keeping the beer at 112˚F for most of a week. I've gone through a few very kludgy solutions to this problem, including placing a keg in a (somewhat) temperature-controlled water bath. My current system is a bit more manageable, consisting of a lamp, a temperature controller, and an unpowered refrigerator. The temperature controller tells the lamp when to turn on and off, and the refrigerator provides insulation. It's basically an incubator. I can maintain my desired temperature (in this case, 112˚F) to within 2˚F for as long as I want.

For this particular sour, I decided to use Brettanomyces as the only alcoholic fermenter. Brettanomyces ("Brett") is an entirely different species from brewer's/baker's yeast. For most brewers and winemakers, it's a scourge to be eradicated, but it also produces characteristic and sought-after flavors in Belgian and American sour beers.

I used a strain of Brett (White Labs Brett Brux Trois) isolated from a bottle of Drie Fonteinen lambic. It has gained something of a following among some American brewers for use in 100% Brett beers. It is markedly less funky (barnyardy, smoky, spicy) than most strains of Brett. Instead, it produces tropical fruit aromas with just a hint of funk.

The grains in this beer (2-row, English medium crystal, flaked barley) would, with a normal ale yeast, produce a fairly typical American pale ale. However, the combination of lactic bacteria and Brett overwhelms the flavor of the malts. The hops are even less distinguishable.

Brewed 3/9/14.

3/16/14: Boiled with 0.3 oz of Columbus. Added Brett Trois. Fermented at 72F.

3/20/14: Medium-high acidity, fruity, slightly savory aroma. Low bitterness. Overall my best sour yet.

Kegged 4/6/14: More Brett aroma. Balanced and fruity.

Simplicity Stout (5/15/13)

Stouts are a great way to use strange ingredients. Since they're so strongly flavored, there's little risk of overpowering the flavor of the beer. As a result, they've become a kitchen sink beer for American (and Scandinavian) brewers. First came the coffee stouts, then the chocolate stouts and vanilla stouts. Then came spiced stouts, fruit stouts, mint stouts, even bacon stouts. Right now the highest-rated Russian Imperial Stout on BeerAdvocate is Three Floyd's Bourbon Barrel Aged Vanilla Bean Dark Lord.

This time, I wanted to take the opposite approach. No weird ingredients, no aging on wood, just an intense, full-bodied beer with a prominent roasted grain flavor. I did use five different types of barley in this recipe, but each plays a vital role. The two row is a fairly neutral base malt; the chocolate malt and roast barley together produce intense and complex roast flavors; the English crystal adds sweetness to balance the bitter roasted grains; finally, the flaked barley adds body. Since aroma is often where regular stouts are lacking, I also added a decent amount of Nugget as an aroma hop, which adds pleasant floral notes.

Had a stuck mash and didn't get very good efficiency. I did a long boil and added a bit of extract to make up for it.

First tasting 10/21/13: Good aroma, balanced flavor profile, excellent mouthfeel. Just enough alcohol in the aroma to add complexity. Subdued but noticeable esters. This beer is great now, but I expect it to continue to improve for at least a year. I will have trouble making it last that long.

ABV: 8.2%
IBUs (Tinseth): 40
OG: 1.082
FG: 1.019

Mash adjustments: 2.5 grams slaked lime, 5 grams calcium chloride
Sparge adjustments: 1 drop 88% lactic acid
Mash temp: 154
Mash length: 60 minutes
Efficiency: 60%

Yeast: Wyeast 1098 British ale yeast (close relation to WLP007)
Starter: 4 liters
Pitching temp: 65F
Max temp: 74F

Malts Mashed		Amount	%	Max Pts.
2 Row		15	79%	36.00
English Medium Crystal		1	5%	34.00
Chocolate		1	5%	28.00
Roast Barley		1	5%	25.00
Barley (flaked)		1	5%	32.00

Other Fermentables		Amount		Max Pts.
DME		2.25		42.00

Hops/Additions		Amount	Time	AA%
Magnum		1	60	14.0%
Nugget		2	5	10.0%

I performed a 90 minute boil to reduce volume.

5/21/13: Gravity is 1.019.
6/4/13: Bottled to 2.3 volumes of CO2.

Mash-up Quick Sour

Over the course of my first three attempts to brew a Berliner weisse, I've learned a few things about brewing quick (i.e., less than 6 months to complete) sour beers—having had to dump two of my first three batches. They weren't poisonous, but they also weren't worth drinking. Sour beer is the one style of beer in which even the most skilled brewers still routinely have to dump batches.

Lesson #1: If you want to make sour beer fast, induce a lactic acid fermentation before alcoholic fermentation. Alcohol seriously inhibits lactic acid bacteria, as do hop acids.

Lesson #2: If you're souring prior to fermentation (and don't have a completely sterile environment), keep the temperature above 110˚F (43˚C), in order to inhibit spoilage bacteria that produce nasty compounds like butyric acid (think vomit, parmesan cheese). Lactobacillus is thermophilic and can handle the heat. Above 115˚F, however, lactic acid bacteria are much slower to produce sourness. Above 140˚F, most bacteria are dead or inactive.

Rather than continuing my attempt to brew a perfect Berliner weisse, I've decided to switch my efforts to attempting the most delicious quick sour I could brew, borrowing techniques from both Belgian and German brewing traditions. My current approach is as follows:

Mash and lauter normally, but instead of boiling the wort, allow to cool to 112˚F (44˚C), then add a handful of crushed 2-row and cover with plastic wrap. Maintain this temperature until the desired level of sourness is reached, sampling daily (2-7 days is a reasonable window). The beer will taste a little bit more sour after most of the sugars have been fermented into alcohol, but it's a minor difference. If the beer starts to smell "off", raise the temperature to 122˚F for 30 minutes. After souring, boil the beer with hops, then cool to 70˚F and pitch your favorite ale yeast. Add fruit if desired after the yeast fermentation is complete.

The main challenge with this technique is keeping the beer at 112˚F. My current set-up consists of an electric heating element and a digital temperature controller, but I've also heard good things about the fermenter heat wraps that homebrew stores sell. If you have little money and much time, intermittent low heat from a stovetop might work. But that would also be a huge waste of energy.

Even though this technique involves spontaneous fermentation, it produces a very clean sour beer. The fact that the beer is boiled after souring also means that almost no bacteria are present in the finished beer, so contaminating your non-sour beers is not a concern. If you want a funkier sour, adding brettanomyces to secondary is always an option, but cross-contamination then becomes a concern again. If you want a sweeter sour, my preferred method is to add a fruit syrup to the glass when serving, as is traditional for Berliner weisse.

Vitals:

OG: 1.056 (pre-souring, pre-boil)
FG: 1.008
ABV: 5%?
IBUs (Tinseth): 15

Water adjustments: 5 grams of calcium chloride
Mash temp: 151F
Mash length: 60 minutes
Efficiency: 75%

Yeast: WLP545
Pitching temp: 70F
Max temp: 71F

Malts Mashed		Amount	%	Max Pts.
2 row		8	74%	36.00
Barley (flaked)		0.75	7%	32.00
English Medium Crystal		2	19%	34.00

Hops/Additions		Amount	Time	AA%
Cascade		0.75	60	6.0%

Beer Glassware

I don't like branded glassware. I find it incredibly tacky and commercial. I have purchased many branded glasses because I like their shape, but I generally remove the brandings with acid. It bugs me to no end that many beer bars devote an enormous amount of labor and shelf space to serving beers in branded glasses.

But it's not just branded glassware. Nearly as irritating to me are those who insist that every beer must be served in a style-specific glass. The only reason pilsners are served in pilsner glasses, while pale ales are served in pint glasses—and not vice-versa—is tradition. Sure, there's an interesting history behind most beer glasses, but with regards to the beer drinking experience, there are only a few aspects of glassware that matter.

Handle: The main benefit of a handled glass is that the beer warms up slower, because the drinker is not holding the glass directly. Therefore, handled glassware is appropriate for large servings of a beer that does not taste good warm. Glass mugs also tend to be thick and sturdy, which is good if you're serving drunk people.

Glass shape: Bowl-shaped glasses (e.g., snifters, tulips, wine glasses) concentrate the beer's aroma. In general, I think beer should be served in bowl-shaped glasses, unless there's a good reason not to.

Glass size: Highly carbonated beers should be served with a good deal of headspace in the glass, so that the inevitable foam can be served, and not dumped down the drain.

Lip flare: Glasses with flared lips (e.g., tulips) make drinking highly carbonated beers easier by allowing the drinker to drink beer from under the foam.

From a functional perspective, therefore, the only types of beer glasses you need are tulips and mugs. I will, however, admit that imperial stouts look funny in a tulip, and prefer to serve them in snifters.

Any glassblowers who want to make me a tulip-stein: hit me up.

How Old is Too Old?

Beer never becomes unsafe to drink, so retailers are under no legal obligation to sell fresh beer. Most people don't think much about beer freshness, so retailers who sell stale beer aren't punished by consumers. However, the age of a beer is vital to its flavor. I don't doubt that some people like the flavors that age and oxidation impart to beer, but I think that most people, like me, dislike these flavors.

Large American lager breweries have spent a great deal of money developing extremely low-oxygen brewhouses and packaging lines to allow their pale, weak beer to last six months in refrigerated storage. Retailers generally understand this shelf life and are able to move these beers on schedule. Craft beers are the problem. Craft brewers produce a huge variety of different beer styles, each of which ages differently. American IPAs are the poster child for beer freshness, since the vast majority of American IPAs are sold extremely stale. Furthermore, craft breweries are often unable to afford refrigerator space in stores, which only worsens the problem.

As my small contribution to fixing the beer freshness problem, here's my impression of the aging potential of various craft beer styles (assuming refrigerated or cellared storage):

American IPA - The most fragile of beer styles. Nearly all of the fresh hop aroma that the brewer has worked so hard to get in the beer will be gone in 1-2 months. The flavors that replace it include molasses, cardboard, and cat piss—none of which I like in beer. Do not age more than six weeks in the bottle/keg.

American/English pale ales - The fresh hop aromas in most American pale ales will fade just as quickly as in IPAs, but pale ales are generally less offensive to drink aged. Nevertheless, don't age them more than three months.

American/English dark ales - Roasted malts are powerful antioxidants. High alcohol stouts are the only beers I brew that actually benefit from extensive aging. Stouts get softer and more complex for at least the first year, and will be delicious for years after, since the roasted malts stave off oxidation. Lower alcohol dark beers don't need as much aging, but will still hold up to a year or two of storage without much trouble.

Belgian pale ales - Tripels, golden strong ales, and saisons have a better shelf life than American pale beers, since they're less reliant on hop aroma, and I think Belgian yeasts have some antioxidant capacity. (Need to confirm.) I'll happily drink a tripel at six months, maybe even a year. I don't recommend longer aging, though some do it anyway. For Belgian pale ales with Brettanomyces, see sour/wild beers.

Belgian dark ales - Dubbels, dark strong ales, and quadruples already have a lot of dark sugar/dark fruit flavors, so oxidative flavors are less obvious. They're not one of my favored styles, so I don't feel qualified to say how long they can be aged, but many people do age them extensively.

German wheat beers - Hefeweizens are known for their banana aroma. The ester associated with this aroma, isoamyl acetate, fades fairly quickly in beer. Less than three months is best with weizens.

Sour/wild beers - Most sour/wild beers take at least a year of fermentation before they're released, so freshness is clearly not paramount here. (Lambics are brewed with aged hops!) But if the beer is pasteurized (as most Flemish sours are), it's best drunk fairly fresh. If unpasteurized, sour/wild beers continue to evolve in the bottle, often becoming more sour and complex. However, aging a live sour/wild beer can also throw off the balance of flavors, and in the case of fruit beers, diminish fresh fruit aromas.

A note on barleywines: One style of beer embraces the flavors of oxidation, just as sherry does in the wine world. That beer is the barleywine. Barleywines don't have roasted malts or wild yeast to protect against oxidation. Nevertheless, they're often aged for many years. Aging does soften the alcohol bite, but it also brings the typical nutty, brown sugar flavors of oxidation. Many people enjoy this in a barleywine. I do not. I don't brew barleywines.

Can't find the date on a beer? For a guide to best by dates and bottling codes, visit http://freshbeeronly.com

Wedding Beers

For my brother's wedding last week, I brewed six batches of beer. They turned out pretty good. My cousin Spencer made wedding-themed labels for each beer. They also turned out pretty good.

Ale We Need is Love – An American amber ale. Lots of hop aromatics, but low levels of bitterness. Flavor notes: pineapple and jasmine aromatics, caramel sweetness.

IBUs: Some

Hoppily Ever After – An American IPA. Fresh hop aromas jump out of the glass. Very bitter. Flavor notes: grapefruit bitterness, passionfruit and pine aromatics.

IBUs: Many

RachAle – A strong Belgian-style ale. Pale to amber in color, highly carbonated. Flavor notes: black pepper, fresh bread, clove, apple.

IBUs: 26

 

Lovey Weisse – Modeled after the sour wheat beers of Berlin, but with two pounds per gallon of whole blackberries added during fermentation. Very light and drinkable, with a pronounced tartness. Available with or without homemade blackberry syrup.

IBUs: 12 

Homebrewing Book Reviews

One of the great things about being a homebrewer today is the breadth and depth of literature that is easily available. The homebrewing books I've read have been nearly all been well-written, well-researched and focused on issues relevant to homebrewers.

Introductory texts:

How to Brew, by John Palmer. For most homebrewers, the only book you'll ever need. It's written so clearly that it's accessible to nearly anyone, but includes in-depth discussion of all the major brewing issues and techniques.

Brewing science:

Principles of Brewing Science, 2nd edition by George Fix. A slim text, but packed with important information. Dense, but accessible to anyone with a scientific bent (no biochemistry background required).

New Brewing Lager Beer by Greg Noonan. Not just for lager brewers, this book reads like an expansion of Principles of Brewing Science, but benefits from the author's experience as a professional brewer. A must-read for anyone thinking of going pro.

Yeast by Chris White and Jamil Zainasheff. Very good discussion of yeast handling and fermentation practices. Some of the information is very much geared towards professional brewers with tens of thousands of dollars to spend, though.

For the Love of Hops by Stan Heironymous. Far and away the most readable of the science-y texts. More relevant information about hop chemistry, hop growing, and hopping techniques than you can find anywhere else.

Beer styles and recipe formulation:

Brew Like a Monk by Stan Heironymous. Very readable. This book is a great guide to brewing Trappist-style beer. (Also covers similar breweries like Duvel, Karmeliet, etc.)

Farmhouse Ales by Phil Markowski. An excellent guide to brewing saisons and bieres de garde.

Wild Brews by Jeff Sparrow. The only text available on sour and wild beers. Poorly written and short on information.

Radical Brewing by Randy Mosher. Probably the most fun brewing book I've read. A must-read for anyone who likes to experiment with new ingredients.

Designing Great Beers by Ray Daniels. Contains good information, but is quite dated, poorly organized, and not much fun to read. Still, if you want to brew traditional English- and German-style beers, it's worth reading.

IPA (4/27/13)

Christened Hoppily Ever After, this IPA is probably the best I've made yet.

The last IPAs I brewed turned out too dry, so for this batch I added more specialty malts and raised my mash temperature. I also increased my hop-stand addition significantly, a decision I made based on the success of my hop-stand amber ale experiments.

My current theory on hopping is that some hops are inherently better suited to dry hopping than hop stand additions, while others are the reverse. Simcoe and Nugget, for example, produce beers with high levels of linalool, a desirable aromatic compound. Linalool, which has a floral aroma, is not itself present in hops, but is produced through enzymatic reactions. Many of these reactions are accelerated by the presence of yeast, so adding linalool-producing hops before fermentation should be advantageous.

Other hops, like Cascade and Amarillo, have very high levels of myrcene. Myrcene, which has a pungent resinous and pine-like aroma, is extracted most effectively after fermentation through dry hopping.

In order to take advantage of both these effects, I've loaded up on the linalool-producing hops in the hop-stand, and saved the myrcene-heavy hops for the dry hop.

Vitals:

OG: 1.066
FG: 1.012
ABV: 7.1%
IBUs (Tinseth): 185

Water adjustments: 7 grams of gypsum
Mash temp: 154F
Mash length: 60 minutes
Efficiency: 65%

Yeast: US05
Pitching temp: 67F
Max temp: 72F

Malts Mashed		Amount	%	Max Pts.
2 row		12	84%	36.00
Belgian Munich		1	7%	36.00
Muntons Crystal 60		0.25	2%	34.00
Barley (flaked)		1	7%	32.00

Hops/Additions		Amount	Time	AA%
Magnum		2	60	13.0%
Chinook		1	60	13.0%
Nugget		1	30	13.0%
Simcoe		1	30	13.0%
Nugget		2	Hop stand	13.0%
Simcoe		2	Hop stand	13.0%

5/5/13: Dry hopped with 1 oz Chinook, 1 oz Cascade, 0.5 oz Simcoe, 0.5 oz Citra (leaf).
5/11/13: Bottled to 2.6 volumes of CO2.

Hoppy Amber II (4/19/13)

Christened Ale We Need is Love, this American Amber is a descendent of my hop-stand experiment. It has no hops in the boil, but lots of hops at 175 degrees. It turned out fantastic.

Vitals:

ABV: 6.5%
OG: 1.060
FG: 1.009
IBUs: 25?

Water adjustments: 3 grams calcium chloride, 2.5 grams calcium sulfate
Mash in: 152F
Mash length: 60 minutes
Efficiency: 67%

Yeast: US-05
Pitching temp: 66F

Malts Mashed		Amount	%	Max Pts.
2 row		8	64%	36.00
Munich		2	16%	36.00
Munich		1	8%	36.00
Crystal 80		0.5	4%	34.00
Barley (Flaked)		1	8%	32.00

Hops/Additions		Amount	Time	AA%
Nugget		2.5	3	13.0%
Simcoe		2.5	3	13.0%

4/25/13: Dry hopped with 1 oz Cascade, 1 oz Chinook.
5/6/13: Bottled #11 to 2.8 volumes of CO2. FG: 1.009

That Belgian Again (4/16/13)

Christened RachAle, this beer is a tweak on the last Belgian ale I brewed. This time I used a lighter (Belgian) Munich, dropped the biscuit malt, lowered the IBUs and added flavor hops (Nugget).

OG: 1.062
FG: 1.009
ABV: 6.9%
IBUs (Tinseth): 26

Mash-in: 150
Mash time: 60 minutes
Efficiency: 70%

Yeast: WLP570 (Belgian golden ale)
Starter: 1 liter
Pitching temp: 66

Malts Mashed		Amount	%	Max Pts.
Belgian Munich		1.5	14%	36.00
2 Row		7.5	68%	36.00
Barley (flaked)		0.5	5%	32.00

Other Fermentables		Amount	%	Max Pts.
Cane sugar		1.5	14%	46.00

Hops/Additions		Amount	Time	AA%
Magnum		0.4	75	12.0%
Nugget		1	5	13.0%

#10 bottled 4/28/13 to 3.3 volumes of CO2.

Robust Porter (4/7/13)

Tasting notes:

Aroma: Chocolate, toffee, fruity esters and (pleasant) spicy alcohol notes.

Taste: Caramel sweetness balanced by a mild roastiness.

Mouthfeel: Medium bodied with moderate carbonation. Light enough to drink easily, but thick enough to support itself.

Overall: Near perfect for a porter in this alcohol range. Balanced and quaffable, but with a lot of depth.

Vitals:

OG: 1.051
FG: 1.012
ABV: 5.2%
IBUs (Tinseth): 33

Water adjustments: 5 grams calcium chloride, 2 grams calcium hydroxide, 1 ml 88% lactic acid
Mash in: 154F
Mash length: 60 minutes
Efficiency: 57%

Yeast: WLP007 (Dry English Ale)
400ml of thick slurry from smoked brown ale (harvested one day earlier)
Pitching temp: 66F
Max temp: 70F

Malts Mashed		Amount	%	Max Pts.
Crystal 90		0.5	4%	34.00
Briess Chocolate		0.5	4%	28.00
Simpsons Chocolate		0.5	4%	28.00
Barley (flaked)		1	7%	32.00
2 row		11.5	82%	36.00

Hops/Additions		Amount	Time	AA%
Magnum		0.75	60	12.0%
Nugget		0.5	5	13.3%

Bottled 4/19 to 2 volumes of CO2.

Smoked Brown Ale With Rye (3/24/13)

I like smoked beers quite a lot, but I've never brewed one before. My favorite commercial examples are Stone's Smoked Porter, Hill Farmstead's Holger Danske, and the classic Schlenkerla line of rauchbiers. The last two of these are both brewed with beech-smoked malt, which tends to be less intense than peat-, apple-, or alder-smoked malts.

For this beer, I wanted to emphasize the food-friendly nature of smoked beers. It is, therefore, moderate in alcohol and bitterness, and full-bodied with a bit of residual sweetness. The half pound of chocolate malt brings a bit of roast flavor (complementing roasted meats and vegetables) without overpowering the beer or the accompanying food. I also added some rye malt to the recipe, which plays well with the smoke and complements a wide variety of savory dishes.

Tasting Notes

Aroma: Soft, savory-sweet beech smoke. Peppery rye. Hint of roast.

Taste: Chocolatey/nutty, with a strong toffee sweetness from the crystal malt. Sweeter than I expected, but still good. Smoke flavor continues throughout, and the rye comes out in the finish.

Mouthfeel: Full-bodied, moderate carbonation.

Overall impression: I very much like the smoke/rye combination. Next time I think I'll cut back on the crystal malt a bit and substitute a de-bittered black malt for half the chocolate.

Vitals

ABV: 5.8%
IBUs (Tinseth): 28
OG: 1.063
FG: 1.019

Mash adjustments: 5.5 grams Calcium Chloride
Sparge adjustments: 1 drop 88% lactic acid
Mash in: 156F
Mash length: 60 minutes
Efficiency: 74% (83% conversion efficiency)

Yeast: WLP007 (Dry English Ale)
Starter: 1.25 liters
Pitching temp: 66F
Max temp: 68F

Malts Mashed		Amount	%	Max Pts.
2 row		2	15%	36.00
Smoked (Beech)		6	46%	37.00
Medium Crystal		1	8%	34.00
Chocolate		0.5	4%	28.00
Malted Rye		2.5	19%	29.00
Barley (flaked)		1	8%	32.00

Hops/Additions		Amount	Time	AA%
Magnum		0.75	60	12.0%

This was my first brew with my new grain mill. The rye malt did not mill very well. I think next time I'll double-crush it.

4/16/13: #7 bottled to 2.2 vol. CO2 Quite smokey, complex flavors, but a bit sweet. The English crystal is very good (toffee/caramel flavors) but a little too intense. Next time I'll drop the crystal to half a pound.

On Failure (3/26/13)

When you write about your own projects, there's always a temptation to emphasize your successes and avoid talking about the mishaps. However, I think that we experimentalists have an obligation to document failures as well as successes.

One of the most spectacular failures of my brewing career occurred with this last attempt at a Berliner Weisse. I performed the same souring technique that I used in my previous, highly successful, batch of Berliner Weisse: Mash and boil normally, then leave the beer at 95F—after adding lactobacillus but before adding yeast—for a few days. I knew something was wrong within 24 hours of souring. Instead of the cabbagey aroma of dimethyl sulfide that I expected, the beer smelled like parmesan cheese. After three days, I tasted very little acidity, so I let it go for another 24 hours. At this point it had some acidity, but it was a back-of-the-throat, acetic acidity, not the clean lactic acid I was hoping for.

The next surprise came when I measured the gravity after souring: 1.005. The beer had already fermented! The lactobacillus should have produced enough acid to deter any other fermentative organisms, but apparently did not. Nevertheless, I boiled the beer for 60 minutes and added a packet of yeast. The beer still smelled strongly of cheese after boiling and fermenting. Not even close to drinkable. I dumped the entire batch and threw out the bucket I fermented it in. This marks the first time I've dumped a batch before bottling.

My theory is that the lactobacillus culture I bought was not viable and hence did not produce enough acidity to protect the wort from the trace amounts of wild yeast and bacteria that managed to infiltrate the covering of plastic wrap and tape that I placed over the kettle during souring. In the future I will make a starter with the lactobacillus to hasten souring and ensure that the bacteria is alive before adding it to a full batch of beer.

Update: Thanks to Greg Noonan's excellent, though technical, book, New Brewing Lager Beer, I now believe that my main problem in this batch was a Gram-negative bacteria known as Clostridium butyricum, which produces butyric acid—a major component of the aroma of Parmesan cheese. In order to protect against these bacteria in the future, I will sour my beers at a higher temperature—say 115 - 120F—because clostridium bacteria are inactive above 112F, while lactobacillus delbruckii is active up to 131F.

Vitals:

Gravity before souring: 1.032
Gravity after souring: 1.005

Mash adjustments: 5.5 grams Calcium Chloride
Sparge adjustments: 1 drop 88% lactic acid
Mash in: 153F
Mash length: 60
Efficiency: 63%

Yeast: US05
Bacteria: Lactobacillus delbruckii (White Labs)
Pitching temp: 65F

Malts Mashed		Amount	%	Max Pts.
2 row		6.5	90%	36.00
Barley (flaked)		0.75	10%	32.00

Hops/Additions		Amount	Time	AA%
Magnum		0.25	60	14.0%

3/29/13: More cheesy than cabbagey aroma during souring this time. Souring has progressed more slowly, although identical inoculation rates and souring temperatures were used. The lack of pilsner malt would explain the lower levels of DMS this time.

3/30/13: 96 hours in. No krausen has formed this time, however, the beer seems to have fermented.  Boiled and pitched US05.

Even after a 60 minute boil and a few weeks of fermentation with yeast, the beer retained a strong parmesan cheese aroma which is quite unpleasant.