Low Dissolved Oxygen (DO) Brewing Lager

Every few years there seems to be some radical underpinning of the brewing word that comes under assault. Remember olive oil instead of oxygen? Saisons fermented above 80F? Dark candi syrup the key to dark Belgian beers? Dry hopping during fermentation? After the debate calms down sometimes brewer's shift their process en masse, and sometimes most of them say it isn't worth the expense/effort/trade-off.


Two things I love about homebrewing are the passion it stirs up, and the flexibility it allows for testing novel techniques. After my friend Trevor talked my ear off about it, I read the German Brewing Forum's collaborative treatise on low dissolved oxygen (Low DO) brewing, The elevator pitch is that to mimic the character of large/classic German breweries (who steam purge equipment and deaerate brewing water) homebrewers need to go to great lengths to limit oxygen pickup on both the hot and cold side. This includes pre-boiling water, dosing oxygen-scavenging sodium metabisulfite, underleting the mash, and spunding their kegs. The supposed payoff is a near mythic German “it” maltiness that Ayinger, Paulaner, Weihenstephaner et al. create that you never taste from craft-brewed examples of helles, dunkel, bock etc.

I decided it was worth a try!

The problem with the method is that, according to the authors, even slight deviations may render the rest of the effort worthless. As little as 1 PPM of oxygen for a few minutes is enough to destroy all of that hard work! I did my best, but didn’t have the effort to go entirely on-method. On the hot side, I used a copper wort chiller (cleaned with StarSan to remove most of the tarnish) instead of stainless steel. On the cold side, I did a more modern lagering method warming rather than cooling towards the end of fermentation to ensure complete attenuation.

The other problem was that I misunderstood the amount of metabisulfite to add. I executed a no-sparge mash as suggested to avoid the risk of aerating during the sparge. The problem was that I dosed my entire mash volume with the rate of campden that they called for (100 mg/L), without accounting for the lower rate (10-25 mg/L) suggested for the sparge. Apparently I wasn't alone because version #2 of the treatise suggests 55 mg/L metabisulfite for no-sparge brewing.

To throw another variable into the mix, I used Weyermann Barke Pilsner for the first time (a sample from BSG, thanks!). This is a new release, an heirloom malt that is lower yielding in the field, but supposedly fantastic to brew with. It is said to replicate some of that elusive maltiness that is difficult to capture for non-German brewers.

The recipe is somewhere between a Pilsner and a Helles (with the other half currently fermenting as a Brett/beet saison, more on that some other week...)

Low DO Pilsner-Helles

Smell – Mostly clean aroma, just a hint of gentle yeasty-apple-fruitiness. Nose isn’t especially malty, I might have confused it for an American Premium if I didn’t know what I was being served. Appropriate waft of sulfur, not out of place. Luckily a "peanut butter" aroma it had early in lagering is gone.

Appearance – Pretty white head, good retention and lacing. One of the palest beers I’ve brewed given the avoidance of Maillard reactions in both malting and brewing. Moderate haze, not off-putting.

Taste – First wort Saphir hops provided a pleasant bitterness with some faint herbal notes. The finish exhibits big doughy malt, more reminiscent of a no-boil Berliner than anything else I’ve brewed. Finish has a hint of chemical-bitterness.

Mouthfeel – Light and crisp, as expected given the low OG. Firm carbonation.

Drinkability & Notes – A solid beer? Sure. Unique? I think so. Worth all the extra effort? Not for this batch anyway! It’s actually one of the lagers I’ve enjoyed least from my last few years of brewing. Not that I brew many, but the lingering flavor isn’t one that calls out for another sip.

Changes for Next Time – Adjust the sulfites to be more in line with the clarified suggestions reduce by 50%). Try going all-in on the Helles recipe, including some caramel malts to see if their flavor shines as noted.

Low DO Barke Pilsner Recipe

Batch Size (Gal): 11
SRM: 2.9
IBU: 21.8
OG: 1.043
FG: 1.009
ABV: 4.4%
Brewhouse Efficiency: 63%
Wort Boil Time: 65 Minutes

Malt
------
100.0 % - 20 lbs Weyermann Barke Pilsner

Mash
-------
Sacch Rest - 30 min @ 152 F

Hops
-------
4.00 oz Saphir (Pellet, 3.00 % AA) @ First Wort

Extras
--------
1.00 Whirlfloc Tablet @ 5 mins
1.00 tsp Yeast Nutrient @ 5 mins

Yeast
-------
Saflager W-34/70

Notes
-------
Brewed 8/7/16

Boiled 18 gallons of water (half distilled, half filtered DC) added 12 g of CaCl and 1 tbls of 10% phosphoric acid. Chilled to 160F, added 15 campden tablets (6,600 mg sodium metabisulfite for 68 L, about the 100 mg/L suggested), crushed. Underlet mash after purging under false bottom with CO2.

Poorer than expected efficiency, likely thanks to a less vigorous crush, brief recirculation, and no sparge.

Chilled to 72 F and transferred 6 gallons out and pitched the Bootleg Biology "Mad Blend." Left at 65 F to ferment. Not aerated initially. 15 seconds of pure O2 after 3 hours, and 6 hours.

Chilled the remaining to 58 F (underestimated the amount of ice needed) and pitched 34/70 (rehydrated, then given an hour on a stirplate with 2 L of diverted wort, and then another hour in the fridge at 48F to acclimate. Not aerated initially. Left at 48F. 15 seconds of pure O2 after 3 hours, and 6 hours. Upped to 52F after 18 hours to ensure it starts quickly.

8/11/16 Moved Saison out of the cold room, to ambient ~75F to finish out. Super sulfury.

8/15/16 Slowly started warming the lager portion 3F each day.

8/20/16 Kegged (well purged) the lager portion with 5.75 oz of Light DME. Left at 65F with the spunding valve set to 30 PSI to carbonate to mid-2s volumes. FG 1.009.

10/8/16 Added 14 oz of shredded beets to the saison secondary. Still pretty sulfury, hoping this helps!

February Kegged.

Fresh vs. Frozen: Mango Tart Saison

June 2015 I found myself with an extra six gallons of low-gravity saison wort, so I decided to ferment it with a vial of East Coast Yeast Bugfarm 15. I was especially intent to trial this iteration of the annual super-blend because it included an isolate of Kloeckera apiculata, a microbe that Vinnie Cilurzo mentioned as a suspect for the citrus-forward character of the spontaneous fermentation of Russian River Beatification!

The result was certainly more lemon and pineapple than funk, but it lacked excitement or depth at a year old. I bottled two gallons as is to see how it evolves (tasting to follow eventually). I racked half a gallon onto wild prickly pears, a gallon onto muscat grapes, and split the rest between fresh and frozen mangoes. The fresh was 1.5 lbs of sliced ataulfo, the frozen was two pounds of 365 Organic Mango Chunks.

I have a pretty flexible palate. I'm generally not a fan of warm citrus or pineapple in savory dishes... but that's about the only thing I won't eat, other than fresh mango! I enjoy mango flavored and infused foods and beverages, but freshly diced mango often has an unmistakable turpentine flavor to me (and not just the "turpentine mango"). Luckily a few delicious mango beers (including Mango Mama from Minneapolis Town Hall Brewery, and a homebrewed pale sour brewed by my friend Seth using four mango varieties from his Florida neighbors' trees) convinced me to brew a batch for myself! I hoped to learn whether fresh or frozen imparted a better flavor.

Fresh Mango Tart Saison

Smell – Pleasant melding of perfume, earthy Brett, light pineapple, and mild toastiness. The Brett picked up in bottle conditioning. Doesn’t have a distinct mango character, even compared to some well-hopped Amarillo IPAs!

Appearance – Bright yellow with mild haze with a few strands of mango pulp. Dense white head exhibits OK retention, leaving a single line of lacing.

Taste – The flavor of the mango comes through more than in the nose, melding with more generic citrus and tropical notes. Mild acidity, dry, but with a perceived sweetness from the general fruitiness.

Mouthfeel – Medium light, slightly slick. Solid medium carbonation.

Drinkability & Notes – Nothing wrong with it, it is nice to have a fruit character that doesn’t cover up the solid base beer… however buying and processing all of that fruit feels like a waste.

Changes for Next Time – I enjoy it, but not sure if the effort of skinning, deseeding, and slicing 10 lbs of mango (to produce 7.5 lbs of flesh) would be worth it for a 5 gallon batch!



Frozen Mango Tart Saison

Smell – There’s the fruit! Like a mango popsicle, big leading juicy tropical fruit. Subdued Brett funk lurking behind as it warms.

Appearance – Same color without the haze or particulate (although there is plenty at the bottom of the bottle). Head retention is a notch lower.

Taste – The flavor is packed with mango, slight aspirin (or Vitamin C?). Bright acidity. Not nearly the depth and complexity of the fresh version, but deliciously refreshing.

Mouthfeel – Feels lighter and quicker, with similar carbonation.

Drinkability & Notes – The mango is so big and bright that the balance is closer to Florida Weisse than a mango-lambic. The base beer isn’t characterful enough to compete.

Changes for Next Time – This one could use something else (like dry hops) to play off of. Otherwise, I might cut the amount back to .75 lbs/gal to get a subtle mango flavor to enhance a characterful base beer.

Bugfarm 15 Tart Saison

Recipe Specifics
--------------------
Batch Size (Gal): 6.25
SRM: 3.3
IBU: 29.1
OG: 1.047
FG: 1.003
ABV: 5.8%
Brewhouse Efficiency: 75 %
Wort Boil Time: 70 Minutes

Grain
-------
82.8% - 9.00 lbs. Rahr 2-Row Brewer's Malt
14.9% - 1.625 lbs. Grain Millers Soft White Wheat Flakes
2.3% - 0.25 lbs. Weyermann Acidulated Malt

Hops
------
.635 oz. Magnum (Pellet, 11.80% AA) @ 60 min.

Extras
--------
.5 tsp Yeast Nutrient @ 5 min.
.5 Whirlfloc @ 5 min.

Yeast
-------
East Coast Yeast ECY01 Bugfarm 2015

Water Profile
-----------------
Profile: Washington, DC

Mash Schedule
-------------------
Sacch Rest - 75 min @ 148F

Notes
-------
Brewed 6/21/15

7 gallons of water, 2 g CaCl, and .25 oz 10% phosphoric acid.

1.5 gallon cold sparge, filtered, untreated. Collected 7 gallons at 1.042. Mash pH 5.53 (room temperature).

Final wort pH 5.62.

Chilled to 80F. Pitched with ECY Bugfarm 2015, no starter. 45 seconds of pure O2, left at 68 F to ferment.

7/14/15 Racked to secondary.

1/2/16 1/2 gallon racked onto .5 lbs of prickly pears from Cape Cod (singed to remove spines, grated discarding skins). Clean acidity, lightly fruity.

4/5/16 Bottled 2.25 gallons with 2 1/8 oz of sucrose. Racked the rest onto 2 lbs of frozen mango, 1.5 lbs fresh ataulfos mango, and 1.5 lbs Muscat grapes from Chile.

7/2/16 Bottled mango, prickly pear and Muscat portions.

Amazon, MoreBeer, and BYO links support the blog!