Low Dissolved Oxygen Lager Brewing

Low Dissolved Oxygen Brewing

We brewed a Vienna lager and dry hoppy pilsner to test the merits of low dissolved oxygen brewing.

It’s no secret that I am a huge fan of brewing and consuming lager beers. I’ve brewed an iteration of my Vienna recipe at least a dozen times and feel like I’ve gotten to the point that I know I can brew a reliably delicious lager. That said, I’m not one to rest on my laurels so when I heard about a technique that promised to further improve my lager beers, I had to give it a try.

Earlier this year, I read a post from The Mad Fermentationist regarding low dissolved oxygen brewing and its use in German lager breweries. Learning about this idea from a respected voice within the homebrewing community gave the concept enough validity for me to give it a try.

The Mad Fermentationist post was spurred by a paper, published on germanbrewing.net in which the authors argue that large scale German brewers are able to achieve a fresh German malt flavor in their beers by dogmatically prescribing to a process which eliminates oxidation on the hot side of their brew house. While most homebrewers have written off hot side aeration as the boogeyman, the paper’s authors argue that the true malt character of a beer is quickly destroyed by the introduction of even minimal quantities of oxygen to the hot side of the brewing process.

It is at this point that the paper gets really interesting, proposing methods in which you can employ low dissolved oxygen brewing on a homebrew level. I won’t rehash the entire paper, but I used the recommended steps below to limit oxygen exposure during my brew process:

  1. Pre Boiling Brewing Liquor: All of the hot water used in my mash was first boiled for 5 minutes, prior to being quickly cooled via a plate chiller to mash temperature and then gently stirred into the mash.
  2. No Sparge: I eliminated the sparging step from my normal brewing process as it offers another opportunity for oxygen ingress into the mash.
  3. Chemical Oxygen Scavengers: Prior to mashing in, my strike water was dosed with sodium metabisulfite which acts as an oxygen scavenger during the mash. I aimed to dose the water with 55 mg/L, the recommended dosing rate for beers employing a no-sparge method.
  4. No Vourlauf: I skipped my normal vourlauf stage as, again, it could be another potential source of aeration in the mash.

The Brew Day

To give low dissolved oxygen brewing a shot, I opted to brew two different beers, a hoppy dry pilsner and a Vienna lager. The paper from germanbrewing.net cites improvements in both hop and malt character, so I figured brewing a hoppy and malty beer would be a good test. Both beers were brewed back-to-back on a single day and fermented with two individually grown cultures of White Labs WLP833.

Pretty early in the brew day, it became apparent that there was going to be a definite impact on the final beer. The first hint was that the mash didn’t smell the way a mash normally does. The aromas seemed muted, with a hint of sulfur in the air. I’ve never used sodium metabisulfite before and figured this was normal and would eventually blow off during the boil and fermentation. Unfortunately, it did not. Again, during the boil, the wort simply did not smell right. More sulfur.

Fermentation & Packaging

Post boil, I rapidly chilled the beer to 50°F and oxygenated the beer as I normally do, inline en route to my fermenter. I immediately pitched my healthy lager yeast starters and set my temperature controller to 50°F. Within 12 hours I had an active fermentation going. Again, smelling the blow-off from the fermentation it seemed to contain a ton of sulfur (much more than I normally get, even with lager yeast).

After about 2.5 weeks of fermentation, inclusive of a diacetyl rest, I carefully racked the beers to kegs using a closed system pressurized with CO2. Once in keg, I pulled a sample to taste. The beers absolutely stank of sulfur and were an undrinkable mess. Ever the optimist, I went ahead a decided to lager the beers under pressure, faithfully purging the keg daily hoping to expunge the vile aromas from the beers. After another 6 weeks of lagering at near freezing, the sulfur compounds remained. Unfortunately, both beers were a lost cause.

Conclusions

These are the first beers that I’ve made in at least the past 5 years that I’ve considered completely unsalvageable.This seemed really odd to me, as the Mad Fermentationist did not have nearly as horrendous results. Something stunk, and it wasn’t just my beer. So I went back to my notes.

My first thought was perhaps I had overdosed the beer with sodium metabisulfite. For the pilsner beer, I dosed the strike water with 11.24 grams of sodium metabisulfite into 20.4 liters of water. Redoing the math, this works our to 550 mg/L of sodium metabilsulfite, not the 55 mg/L that I was shooting for. Evidently I failed in my studies of the metric system and buggered up a decimal point, not just once, but twice. I felt like a complete idiot having only definitively proven that dosing a mash with 550 mg/L of sodium metabisulfite will make your beer stink really badly. That said, this project serves as a good reminder that attention to detail is key to successful brewing and even the most minor of an error can really screw up your beer.

Now that I have a clear grasp of junior high school level math, I think it’s mandatory I repeat the experiment using the appropriate levels of sodium metabisulfite. Stay tuned!

Hoppy Dry Pilsner Recipe

Specifications:
Size: 3.25 gal
Efficiency: 70% (No Sparge)
Attenuation: 84%

Original Gravity: 1.052
Terminal Gravity: 1.008
Color: 4.25 SRM
Alcohol: 5.78% ABV (calculated)
Bitterness: 18.8 IBU (does not account for significant whirlpool isomerization)

Malt Bill:
5.0 lbs. (74.1%) Weyermann Pilsner Malt
1.0 lbs. (14.8%) Weyermann Vienna Malt

Sugar Additions:
0.75 lb. (11.1%) Dextrose (Corn Sugar)

Mash Profile:
149°F – 60m

Water Treatment:
Extremely Soft NYC Water
3 g. Calcium Chloride (to mash)
55 mg/L Sodium Metabisulfite (to strike water).

Hopping:
6 g. Warrior (15.4% AA) – 90m
25 g. Hallertauer Hersbrucker (2.5% AA) – Whirlpool 10m
25 g. Cascade (6.9% AA) – Whirlpool – 10m
25 g. Czech Saaz (2.2% AA) – Whirlpool – 10m

20 g. Czech Saaz (2.2% AA) – Dry Hop 3 Days
20 g. Hallertauer Hersbrucker (2.5% AA) – Dry Hop 3 Days

Kettle Additions:
0.5 ea. Whirlfloc Tablets (Irish moss) – 15m
0.5 tsp. Wyeast Nutrient – 10m

Yeast:
White Labs WLP833 German Bock Lager

Hoppy Dry Pilsner Tasting Notes:

Judged as a BJCP 5D. German Pilsner

Aroma (2/12):
This beer has a very high sulfur aroma that reminds one of burnt matches, egg, and perhaps even a little bit of cooked cabbage. It is very hard to get past the overwhelming sulfur in this beer. That said, there is some light bready malt. The ample hopping is just barely perceptible, largely due to the abundance of sulfur. This is pretty offensive.

Appearance (3/3):
This is a beautiful beer. The beer strikes a crystal clear, light golden hue. There is a low white persistent head with big foamy bubbles and excellent lacing.

Flavor (4/20):
I recently heard during a brewer interview on The Brewing Network that sulfur compounds are largely not perceivable by our taste buds and that most of the perception we get of sulfur in beer is either on the nose or via retronasal breathing after we swallow. This certainly is apparent in this beer as the actual flavor is much better than the aroma with the most offensive sulfur coming through post swallow. The malt character of this beer is pretty pleasant, clean, slightly sweet, and bready. The beer is quite crisp and dry. There is a medium-plus hop flavor that is a bit floral with just a hint of citrus. The bitterness is firm, but pleasant. This would be an excellent beer if there wasn’t such a blast of sulfur.

Mouthfeel (5/5):
The beer has a medium-low body and features a great crisp effervescence. Very lean and drinkable.

Overall Impression (2/10):
Without the sulfur, I’d be willing to bet that this is a 40+ point beer. Unfortunately, the sulfur is so utterly offensive that it is tough to evaluate the beer that lies beneath.

Fair (16/50)

Bonus: See how judges scored this German Pilsner at the 2017 Homebrew Alley competition in NYC.

Vienna Lager Recipe

Specifications:
Size: 3.25 gal
Efficiency: 64% (No Sparge)
Attenuation: 84%

Original Gravity: 1.052
Terminal Gravity: 1.008
Color: 10.75 SRM
Alcohol: 5.73% ABV (calculated)
Bitterness: 21.6 IBU

Malt Bill:
5.0 lbs. (64.5%) Weyermann Vienna Malt
1.50 lbs. (19.4%) Weyermann Dark Munich Malt
1.25 lbs. (16.1%) Weyermann Pilsner Malt

Mash Profile:
147°F – 60m

Water Treatment:
Extremely Soft NYC Water
3 g. Calcium Chloride (to mash)
55 mg/L Sodium Metabisulfite (to strike water).

Hopping:
1.5 oz. Hallertauer Hersbrucker (2.5% AA) – 90m
0.5 oz. Hallertauer Hersbrucker (2.5% AA) – Whirlpool 10m

Kettle Additions:
0.5 ea. Whirlfloc Tablets (Irish moss) – 15m
0.5 tsp. Wyeast Nutrient – 10m

Yeast:
White Labs WLP833 German Bock Lager

Vienna Lager Tasting Notes:

Judged as a BJCP 7A. Vienna Lager

Aroma (4/12):
The beer has a medium-plus sulfur nose reminiscent of cooked eggs and burnt matches. Compared to the pilsner, the sulfur is less intense, although the character is extremely similar. There are some nice toasty malt aromas that just peek out beyond the sulfur.

Appearance (3/3):
The beer is a beautiful sparkling clear light copper color that sits just at the bottom end of the SRM range for the style. The beer features golden orange highlights when held up to the light and is capped with a mousey white head that persists. Some judges may argue that the beer is too light, but I think it’s spot on.

Flavor (8/20):
As with the pilsner, the sulfur is present, but much less dominate on the palate than the nose. Getting past the sulfur, there is a really nice toasty malt component that has a drying character to it. This beer is not nearly as intense in malt sweetness and complexity as many craft examples, but is perfect for being the session beer that I think Vienna Lager should be. On the finish is a firm bitterness that further accentuates the beer’s dryness. This beer reminds me of Sierra Nevada’s 2016 version of Oktoberfest which this past year was lean on the malt, and spicy in its hop character.

Mouthfeel (3/5):
The beer has a medium-low body with plenty of crisp carbonation that is perhaps a touch high, but quite pleasant and refreshing.

Overall Impression (4/10):
Again, this could have been a really excellent beer if it wasn’t for the offensive sulfur character that is dominating, particularly on the nose. The recipe is somewhat on the lower end of the intensity spectrum for the style, leaving it much more quenching than many of the craft examples that I’ve tasted.

Good (22/50)

Bonus: See how judges scored this Vienna at the 2017 Homebrew Alley competition in NYC.

Irish Stout – Recipe & Review

Drinking Guinness at St. James's Gate

An early sighting of this Pour Reporter at St. James’s Gate way back in 2003.

Back in the day, I remember feeling a certain bravado and sense  of sophistication when ordering a pint of Guinness.

It’s dark! It’s so thick! Look at the head and those bubbles!

Today I consider Guinness the bunny hill of craft beer slopes. But back then, it was GUINNESS. It was different, so much older than the American macro lager I was accustomed to. Something with flavor. Something exotic. Something authentic. In spite of the feelings I have today, Guinness will always invoke a sense of nostalgia and serve as a delicious reminder of when I first started exploring the world of beer.

Somewhat ironically, I had always thought of Guinness a filling beer, something thick. Only with age and beery wisdom, have I come to see it as something quite the opposite. A session beer that happens to have tons of flavor without imposing heavy caloric tariffs on my waste line or alcoholic ones on my liver. So in honor of St. Patrick’s day, an homage to one of my earliest beers of choice. This version has a bit more roast character, but I think it is on par in sessionability and deliciousness to the original Irish Stout.

Irish Stout

Don’t let the snifter fool you, this is a beer built for sessionability.

Irish Stout Recipe

Specifications:
Size: 3.25 gal
Efficiency: 72%
Attenuation: 75%

Original Gravity: 1.047
Terminal Gravity: 1.012
Color: 32.8 SRM
Alcohol: 4.2% ABV (calculated)
Bitterness: 37.3 IBU

Malt Bill:
4.25 lbs. (69.4%) Crisp Maris Otter
1.0 lb. (16.3%) Briess Flaked Barley
6 oz. (6.1%) Muntons Roasted Barley
4 oz. (4.1%) Thomas Fawcett Chocolate Malt
4 oz. (4.1%) Briess Midnight Wheat

Mash Profile:
150°F – 60m

Water Treatment:
Extremely Soft NYC Water
2 g. Gypsum (to mash)
5 g. Chalk (to mash)

Hopping:
1 oz. East Kent Goldings (5.1% AA) – 60m

Kettle Additions:
0.5 ea. Whirlfloc Tablets (Irish moss) – 15m
0.5 tsp. Wyeast Nutrient – 10m

Yeast:
Wyeast 1056 American Ale

Tasting Notes:

Judged as a BJCP 15B Irish Stout

Aroma (8/12):
Moderately high aroma of roasted malts, with some complexity including notes of dry baker’s chocolate, coffee, and a touch (perhaps too much) of ashy and smoky roast. The roast is somewhat aggressive and pushes the upper end of the style limit. Beyond the roast is a very nice bready, slightly sweet malt component that is quite inviting, like baking bread. No crystal sweetness, hop character, or fermentation esters.

Appearance (3/3):
Quite black, although if you hold the edge of the glass to the light you see some very dark ruby notes. Large, soapy bubbles build a nice persistent tan head.

Flavor (17/20):
The roasted flavor is a bit less than the nose would have hinted at, but has a nice round baker’s chocolate character. The roast is quite drying on the tongue. There are some pleasant toasty malt flavors, but the beer is devoid of any sweet caramel or toffee character. There is a firm medium-plus bitterness that leaves the palate quite dry, especially when combined with the roast.

Mouthfeel (5/5):
Medium body with a nice fullness that avoids being too filling. The mouthfeel is pretty exceptional considering the low starting gravity of this beer. There is a slightly acidic tang that brightens the palate and gives the beer a bit more personality.

Overall Impression (7/10):
The is a great iteration of Irish Stout; though it pushes the upper limit of roast that I would expect in this style, especially when compared to a macro commercial example like Guinness. The roast has a slight acrid note that I’d prefer didn’t exist in the beer and probably could be eliminated by choosing a different maltster, other than Muntons for the roasted barley.

Excellent (40/50)

English Bitter Homebrew Recipe & Review

bitterMalty. Dry. Balanced. These are the characteristics I prize most in a well-made British session beer. I am a firm believer that the judicious use of high quality English base malts like Maris Otter will take you most of the way in achieving an interesting and nicely balanced bitter. A touch of crystal, herbal hops, and fruity yeast act as the seasoning that takes you the rest of the way.

With all the hoppy, sour, and high alcohol beers I’ve been brewing, a sessionable bitter was a great change of pace.

English Bitter Recipe

Specifications:
Size: 3.25 gal
Efficiency: 67% (measured)
Attenuation: 72% (measured)

Original Gravity: 1.048
Terminal Gravity: 1.011 (measured)
Color: 32.8 SRM
Alcohol: 4.8% ABV (calculated)
Bitterness: 14.11 IBU (does not account for IBUs created by whirlpool hop addition)

Malt Bill:
6lb (92.3%) Crisp Maris Otter
0.25lb (3.8%) Thomas Fawcett 45L Crystal Malt
0.25lb (3.8%) Bairds Crystal 130

Mash Profile:
150°F – 60m

Water Treatment:
Extremely Soft NYC Water
2g Gypsum (to mash)
2g Calcium Chloride (to mash)

Hopping:
1oz East Kent Goldings (5.7% AA) -60m
2oz East Kent Goldings ((5.7% AA) – Whirlpool 15m

Kettle Additions:
0.5ea Whirlfloc Tablets (Irish moss) – 15m
0.5tsp Wyeast Nutrient – 10m

Yeast:
Wyeast 1469 West Yorkshire Ale

Tasting Notes:

Judged as a BJCP 8B Special Bitter

Aroma (10/12):
Moderately intense fruity esters upfront that have almost an apricot and perhaps cherry character. Below this is a round toasty malt note with just a hint of caramel and toffee. The inviting nose finishes with a whisper of herbal and floral hops that have just a hint of a rose character.

Appearance (1/3):
Light copper with a noticeable haze. Head is bright white with great persistence.

Flavor (16/20):
Medium-full malt greets you with notes of freshly baked bread, toasty crust, and just a hint of deep caramel and raisin. There is a good amount of toffee as well. The hop bitterness is medium-low, enhancing an already dry finish. There is a slight mineral character on the finish.

Mouthfeel (4/5):
Medium-low body with a full creamy mouthfeel. Carbonation is medium-low and to style. There is a slight minerally astringency on the finish.

Overall Impression (8/10):
This is a beautifully balanced beer where none of the constituent ingredients feel out of place with the overall beer. The yeast character is really unique among English strains and gives the beer a delicious character not seen in many English bitters. Really nice.

Excellent (39/50)

 

Chuck’s Mexican AKA HBC 438 Blond Ale

Chuck's Mexican Blond

Chuck’s Mexican Blond

Way back in 2015 at the National Homebrewers Conference held in San Diego, Jason Perrault of the Hop Breeding Company (HBC), Karl Vanevehoven of Yakima Chief Hopunion (YCH), and Vinnie Cilurzo of Russian River Brewing Company gave a great talk about a new hop variety called HBC-438. The hop is lovingly referred to as Chuck’s Mexican, having originated from Chuck Zimmerman, a breeder at the USDA, and sharing a genetic lineage to neomexicanus, a wild hop found in the southwestern United States. The history of how this hop has made its way into homebrewer’s kettles is fascinating and can be read here. Origin story aside, what intrigued me the most about the hop was its relatively high alpha acid (14-18%) and high oil contents (2.5-3.5 ml/100g). Additionally, I love the idea of using a hop with at least some of its lineage tied to the Americas.

At the conference, I was given a couple ounces of the hop which lived in the back of my freezer until nearly a year later when I got around to brewing with them. I was a little concerned about the freshness of the hops, but decided to go ahead and give them a shot in a single hop beer. Opening the vacuum sealed bags, there was no detectable cheesiness or other off-aromas so I was optimistic that the brew would turn out well.

Chuck’s Mexican Blond Ale Recipe

Specifications:
Size: 3.25 gal
Efficiency: 66%
Attenuation: 76%

Original Gravity: 1.050
Terminal Gravity: 1.012
Color: 7.82 SRM
Alcohol: 4.98% ABV
Bitterness: 0 IBUs (does not account for whirlpool addition hop isomerization)

Malt Bill:
6 lbs (83.1%) Weyermann Pilsner Malt
6.5 oz (5.6%) Briess Victory Malt
6.5 oz. (5.6%) Weyermann Rye Malt
6.5 oz. (5.6%) Rahr White Wheat Malt

Mash Profile:
152°F – 60m
170°F – 5m

Water Treatment:
Extremely Soft NYC Water
4g Gypsum (to mash)
2g Calcium Chloride (to mash)

Kettle Additions:
0.5ea Whirlfloc Tablets (Irish moss) – 15m
0.5tsp Wyeast Nutrient – 10m

Whirlpool Hopping:
2 oz. HBC-438 (16.6% AA) – 20m

Yeast:
Wyeast 2565 Kölsch

Tasting Notes:

Judged as 2015 BJCP Category 18B American Pale Ale

Aroma (5/12):
The beer has a medium to medium-high fruity character that seems to be equal parts hop and expressive yeast. There is a moderate berry character—maybe blackberry as well as some overripe, almost rotten mango notes. The yeast is slightly sulfury / eggy, which may dissipate with some extended cold storage. There is a weird, almost savory / herbal note that seems to be hop-derived. In the background are some nice toasty / biscuity malt aromas.

Appearance (3/3):
Deep gold with good clarity. Just a touch of light haze. The beer is capped with a big fluffy white head that shows excellent persistence.

Flavor (9/20):
Medium to low malt sweetness upfront with some great toasty malt flavors. The beer is a touch oversweet and could benefit from some more hop bitterness. There is a touch of mineral / seltzer water character on the finish. Again, there is a bit of a weird herbal / savory hop flavor that my palate doesn’t enjoy.

Mouthfeel (5/5):
Medium body with a great roundness / silkiness provided by the rye. Medium to medium-low carbonation. Very pleasant.

Overall Impression (4/10):
I’m pretty surprised at how hoppy this beer is considering the low hopping rate and age of the hops. I can say unequivocally that HBC-438 has a very unique profile. Unfortunately, for me, it contributes an unwelcome melange of overripe berries and savory herbs, which don’t quite jive with my tastes.

Good (26/50)

Mixed-culture Saison – Hops vs. Lacto!

Hoppy Mixed Culture Saison

Great head retention, on this beautiful golden saison.

I’ve had a lot of fun over the past couple of years maintaining a mixed culture of Sacc, Brett, and Lacto; and using it to make some pretty nice tart, funky saisons. The culture started its life as a blend of cultures grown from Saison DuPont bottles, The Yeast Bay’s Amalgamation Brett Blend, and White Labs Lacto Brevis. Over the 6+ generations I’ve used the culture, it continues to produce great beers that have an awesome Brett fruitiness that plays especially nicely with big punchy dry hops. Initially, I was very concerned that too much drift would occur in the blend of different organisms, but the culture has remained remarkably consistent in its fermentation characteristics—something I hope stays true for many more generations.

One thing that I’ve always known is that this mixed culture reacts differently to varying levels of kettle hopping, especially in terms of lactic acid production. I’ve observed this anecdotally over several batches, but never completed a side-by-side experiment. For fun, I decided to actually test the culture on two very similar worts to see just how different the beers would become.

For starters, I used the hoppy saison recipe that has turned out quite good in the past.

Base Saison Recipe

Specifications:
Size: 3.25 gal
Efficiency: 69%

Original Gravity: 1.050
Color: 4.45 SRM
Bitterness: 0 IBUs

Malt Bill:
5 lbs (71.4%) Weyermann Pilsner Malt
1 lb (14.3%) Flaked Oats
1 (14.3%) Weyermann Rye Malt

Mash Profile:
150°F – 60m
170°F – 5m

Water Treatment:
Extremely Soft NYC Water
4g Gypsum (to mash)

Kettle Additions:
0.25 ea Whirlfloc Tablets (Irish moss) – 15m
0.25 tsp Wyeast Nutrient – 10m

Yeast:
Mixed Saison Culture

The Experiment

Two identical batches using the above recipe were brewed back-to-back. The key difference is that Batch 1 received hopping at the end of the boil in the whirlpool, whereas Batch 2 did not and was instead given a post-fermentation dry hop. Other analytic differences between the two batches are outlined below.

Batch 1  – Whirlpool Hopped at End of Boil
Hopping:
2 oz. Mosaic (12.3% AA) – Whirlpool 15 m
4 oz. Azacca (10.3% AA) – Whirlpool 15m

Attenuation: 76%
Terminal Gravity: 1.012
Alcohol: 5%
pH: 3.27

Batch 2  – Dry Hopped Post Fermentation
Hopping:
No hops before fermentation.
2 oz. Mosaic (12.3% AA) – Dry Hop 2 Days
2 oz. Azacca (10.3% AA) – Dry Hop 2 Days

Attenuation: 80%
Terminal Gravity: 1.010
Alcohol: 5.24%
pH: 2.71

The Results

Both batches of beer turned out extremely unique (and quite delicious). I am guessing most people would be surprised to find out that the two beers were produced from the same mixed culture and remarkably similar recipes.

As expected, the whirlpool hopped beer developed significantly less acidity than the batch that was not hopped prior to fermentation. Tasting the beers, it is very obvious that the beer that did not receive kettle hopping is significantly more sour than the beer that was hopped in the whirlpool. That said, the whirlpool hopped beer did develop a light lactic tartness that is consistent with its 3.27 finishing pH.

It is also interesting to note that the kettle-hopped beer attenuated slightly less than the beer that only received a dry hop. I would have thought the opposite would have occurred with the lower pH inhibiting attenuation by the Brett / Sacc in the culture. The difference of .02 SG is probably not significant enough to draw any real conclusions, but it is an interesting anecdote.

The sensory aspects of the two beers are strikingly different. The beer that received kettle hopping ultimately developed a much higher level of the traditional flavors attributable to the Brett in the mixed culture (funk, overripe fruit) whereas the Lacto-heavy dry-hopped beer is much more two note with lots of acid and a significant fruity, dry hop character. It is unclear to me why the kettle-hopped beer developed more Brett character and it will be interesting to see if the dry-hopped beer eventually develops these characteristics. I hope to keep some of the beer around to see if the flavors ultimately converge at a single point or whether they continue to remain two incredibly different beers.

UPDATE: The dry-hopped version of this beer placed first in Category 28, American Wild Ale at the 2016 Joint Novembeerfest / Puget Sound Pro-Am.