Article

Hoppy Sour Beers

Hoppy SaisonNone of the classic sour beer styles leave much room for hop character. In the opening remarks for the European sour ale category, the 2015 BJCP Guidelines suggest: “Most have low bitterness, with the sourness of the beer providing the balance that hop bitterness would otherwise contribute.” Each style notes some variation on both “No hop aroma” and “No hop flavor.” Lambic and gueuze brewers age their hops, reducing bitterness; for other styles brewers usually add a light touch of a low alpha acid variety near the start of the boil. However, with the right recipe design philosophy, why shouldn’t the apricot aromatics of Amarillo® or the passion fruit notes of Galaxy find a home against the backdrop of tart acidity and lemony Brett of a sour beer?

On our tongues (or more accurately in our brains) assertive acidity and bitterness clash, while the other primary taste combinations harmonize at moderate intensities. Maybe bitter plus sour triggers the “poison detector” that our brains evolved for foraging, but whatever the reason a sour double IPA isn’t appealing!

While IBUs fade with time, the half-life of the various iso-alpha-acids is not rapid enough to bring high bitterness down below the flavor threshold within a couple years (30 IBUs is reduced to approximately 23 after one year, and 18 after two). As a result, the sour beer brewer’s goal is to deliver hop aromatics without much of the associated bitterness. This isn’t the only hurdle to brewing hoppy sour beers though, read on!

From a microbiological standpoint, hops gained brewers’ favor for their antimicrobial properties. Hops are especially inhibitory to Lactobacillus, one of the two lactic acid bacteria primarily responsible for sour beer acidification. To ensure lactic acid generation, you should either pitch a less hop-sensitive bacterium, or wait to add hops until after souring.

Another potential area for conflict derives from the fleeting nature of hop aromatics. Hop essential oils are one of the first components to oxidize and fade, but traditional sour beer production requires substantial aging. Consequently, we need to either speed up the souring and fermentation, or have the patience to wait to add hops close to the time that our beer is ready to serve.

This article includes three methods that I use to brew hoppy sour beers, each of which addresses sour beer challenges in a unique way. Why the effort? All beers are slightly acidic, typical final pH ranges from 4 and 5. However, it isn’t until the pH falls below 4 that we begin to register a beer as sour. Many brewers add a small amount of acid to bring their West Coast IPAs below 4.5 pH. This results in a crisper flavor, and a somewhat heightened perception of bitterness. New England IPAs taste smoother and rounder when their pH is allowed to rise above 4.5.

Citrusy, tropical, and juicy aromatics are de rigueur for new hop varieties, not only from the US but also Australia, New Zealand, Germany, and even South Africa. Here are the descriptors for a smattering of new cultivars: Floral-citrus, dark fruit, pineapple, passion fruit, lemongrass, grapefruit, honeymoon melon, and strawberry. We are accustomed to these engaging aromatics combined with the natural acids (e.g., malic, citric) from fruit itself so the combination of acidity with these hop aromatics can provide an impression of a fruit beer!

Aggressive bitterness and acidity seem to be losing popularity among craft brewers and beer drinkers. No longer do I see brewers one-upping each other bragging about pushing the IBU-envelope to 200, 300, or 1,000. Many are focusing on what makes hops so interesting: Their volatile aromatics! They are limiting bittering additions in favor of huge whirlpool, hop stands, and multiple dry hop additions. The classic dry, clear, neutral-yeast, “hop-solvent” IPAs are not going away, but there is increased interest in other expressions of hop character. Thus the excitement over New England IPAs (see “Rise of the Haze” in the October 2016 issue of BYO) and the push for yeast-hop interactions. So too, acidity isn’t “the point” of sour beers, the goal should be tart-bright-quenching-balanced beers with interesting aromatics from the fermentation and interactions with oak, fruit, malt, and hops. Maybe sours will finally be “the next IPA” by emphasizing the hop character that made IPA the tent pole craft beer style!

In addition to the direct aroma-plus-flavor pairing, sours and hops have a special relationship through glycosides. These water-soluble molecules combine a sugar and a functional group (often an aroma molecule) and can be freed by acidity or enzymatic action. The result is a brighter, fruitier, less “green” grassy hop aroma. Rather than get too deep here, I’ll direct you to “The Science of Hop Glycosides: Hop Aroma” in BYO’s July-August 2015 issue. Brettanomyces also has the ability to biotransform some hop compounds into other aromatics. In addition, Brett scavenges oxygen, protecting the hop aromatics in a way that Saccharomyces is unable. As with any sour beer, hoppy sours tend to age gracefully with the aromatics fading rather than flying off a cliff!

History To Now

Like most beer ideas, hoppy sours weren’t invented by an American craft brewer, but American craft brewers certainly expanded and popularized the combination!

While the original India Pale Ales of 19th century England were not sour, they were influenced by Brettanomyces during months of aging and transit. Early saisons were the first beers that were intentionally hoppy and acidic. Yvan de Baets writing in Farmhouse Ales (Brewers Publications, 2004) notes that initially hops were probably added to regulate, not stop, bacteria. These saisons had a range of balances from acidic to hoppy with a “sour sidenote nonetheless.” Dry hopping was widespread, especially to “rejuvenate old beers” at a rate of 0.15–0.5 oz per gallon (1.1–3.75 g per L).

For American brewers, Brasserie Cantillon Cuvée Saint-Gilloise (née. Des Champions) was likely the beer that demonstrated that hops and sour are not on opposite ends of a spectrum, but separate sliders. To produce it, Cantillon dry hops two-year-old lambic with classic varieties such as Hallertau or Styrian Golding. Iris is similar, but it is the only beer Cantillon brews regularly which is not a true lambic (owing to a grist of 100% barley malt, when 30% unmalted wheat is required). Iris is brewed with 50% aged and 50% unaged hops, and dry hopped with Hallertau for the final two weeks of its two-year fermentation.

The first widely-available American beer to combine acidity and hop aromatics was Le Terroir from New Belgium Brewing Co. in Fort Collins, Colorado. It was inspired by Specialty Brand Manager/Blender/Sensory Specialist Lauren Salazar’s revelation in 2003 that a particular foeder of Felix, their pale sour base beer, possessed aromatics of peach, citrus, and mango reminiscent of Amarillo® hops. The result is bright and lively, without exception my favorite beer in their lineup. One particular batch was dry hopped at a rate of 1 lb. Amarillo® and 0.25 lb. Citra® per barrel (3.9 g and 1 g per L respectively). The 2015 batch replaced Citra® with Galaxy, and 2016 in turn with Crystal. According to New Belgium’s blog (http://www.newbelgium.com/community/Blog/new-belgium-brewing/2016/08/25/inside-this-year-s-vintage-of-le-terroir-dry-hopped-sour-ale), Lauren noted from blind tasting a variety of hop teas, “Crystal was the winner: It had melon rind, guava, and it was demure and classy.”

Almanac Beer Co. (San Francisco, California) has made nearly a dozen hoppy sour variants (e.g., Hoppy Sour: Azacca®). Jesse Friedman, co-founder and brewmaster, gave me the background on their process and a few highlights of their learnings. The pale base beer undergoes primary fermentation with Brett followed by six-to-nine months of barrel-aging with Lacto and Pedio. From there they blend barrels of various ages into stainless steel tanks with 2.5-3 lbs./bbl (10-12 g/L) of hops for only a few days. What really struck me was Jesse’s descriptors of where the hop aroma ends up once it mingles with the sours: Citra® “freshly cracked can of Sprite,” Amarillo® “Dole pineapple juice blended with bosc pear juice,” and Simcoe® “exactly like freshly zested limes in a bag of weed.” Luckily so far none of their varieties have failed, although a few have been less interesting than others.

Three Homebrew Methods

I brewed three hoppy sours to serve at HomebrewCon 2016 as part of a seminar on hoppy sours. I wanted to demonstrate how the aromatics from the same hops (equal parts Citra®, Simcoe®, and Mosaic® would change depending on the method used. The recipes for all three are included in this story, but don’t feel that you should limit the process to the recipe. Swap the hops, alter the grain bill, use your favorite microbes, but leave the timing and order the same.

1. Quick mixed fermentation with low-temperature whirlpool hops.

2. 100% Lactobacillus souring, pasteurized with hops*, and then 100% Brett.

3. Traditional mixed fermentation, aged and then dry hopped.

I wouldn’t treat the water for a hoppy sour the same way as an IPA. The sulfate in gypsum (or Epsom salt) accentuates bitterness, something that isn’t desirable here. Instead, use calcium chloride for your calcium needs. Chloride has the benefit of improving mouthfeel, something that can be beneficial to a dry beer where assertive flavors are at work. I aim for 100–150 PPM. While I dilute my filtered tap water with distilled to reduce carbonate for most hoppy beers (for a crisper flavor and to reduce my need for acid additions) the lactic acid produced in a sour beer will drop the pH adequately no matter how much buffering capacity your water has.

Method #1: Classic Mixed-Fermentation Saison

The easiest, but least reliable, method is to simply brew a beer with very low bitterness and ferment with a hop-tolerant strain of Lactobacillus and a saison strain. It isn’t the iso-alpha acids alone that inhibit Lactobacillus, so chilling the wort below 180 °F (82 °C) prior to the hop stand does not allow free work by Lactobacillus (although it does reduce the perceived bitterness).

Even if your pH begins to drop, you may be able to blame a stall on the hops. The lower the pH, the higher the antimicrobial potency of hop compounds. One study suggested that a pH below 4 greatly increases the antimicrobial potency of iso-alpha-acids.

Adding the hops on the hot side demands speed as well. A funkier Brett strain that can make its presence known in a few weeks is important. This is a time when pitching an active starter of Brett may be worthwhile. I also find that natural conditioning (either in a keg or bottle) helps to bring out the Brett character quickly. The nice advantage of a keg is that you can fill it before the final gravity is reached and either vent excess pressure or attach a spunding valve.

By reducing the hopping rate, or building hop-tolerance into the bacteria through culturing in increasingly hopped media (e.g., add a couple hop pellets to your starter wort, step up with a few more) you can make a more or less acidic beer.

I fermented this batch (see recipe on page 67) with a house saison culture that I’ve been maintaining for more than two years. Jeff Mello from Bootleg Biology took a look at the slurry harvested from this beer under a microscope and noted that there are unidentified bacteria present, but they are clearly not as hop-tolerant as I had hoped!

Method #1: Hoppy House Saison

(5 gallons/19 L, all-grain)
OG = 1.048 FG = 1.004
IBU = 0 SRM = 4 ABV = 5.7%

Tasting Notes: pH = 3.87. Big/fresh hop nose, still more fruit than green (truer than a New England IPA with the same hops that I fermented with Wyeast London III and GigaYeast Vermont IPA). Bright, lively Brett-like character, tropical, but not juice. Finish brings in some funk, impressive for less than two months since brewing. Acidity is tangy at best, more saison than sour.

Ingredients

7.5 lbs. (3.4 kg) Rahr 2-row Brewer’s Malt
2 lbs. (0.91 kg) flaked wheat
0.25 lb. (113 g) acidulated malt
1 oz. (28 g) Simcoe® hops (hop stand)
1 oz. (28 g) Mosaic® hops (hop stand)
1 oz. (28 g) Citra® hops (hop stand)
0.5 oz. (14 g) Simcoe® hops (dry hop)
0.5 oz. (14 g) Mosaic® hops (dry hop)
0.5 oz. (14 g) Citra® hops (dry hop)
The Yeast Bay Saison Blend yeast
White Labs WLP644 (Saccharomyces “bruxellensis” Trois) yeast
Omega Yeast Labs OYL-605 (Lactobacillus Blend) bacteria
3⁄4 cup corn sugar (if priming)

Step by Step

Mash at 150 °F (66 °C). Collect wort and boil for 60 minutes. Turn the heat off, and either use a wort chiller to force the temperature down to 180 °F (82 °C) or simply allow to cool with the lid off for 30 minutes. Add the hops and allow to steep for 20–30 minutes before fully chilling. Transfer the chilled wort to a fermenter. Aerate and pitch the saison yeast and Lactobacillus of your choice (Brett is optional). Ferment at 73 °F (23 °C). Approximate fermentation time in primary is two weeks. Once the gravity stabilizes, the beer is ready to package. If you are bottling, add the dry hops to the primary fermenter. If kegging, bag and weight the hops (I use new nylon knee highs and glass marbles) adding them directly to the keg during natural conditioning. Either way, aim for 2.7 volumes of CO2.

Hoppy House Saison

(5 gallons/19 L, partial mash)
OG = 1.048 FG = 1.004
IBU = 0 SRM = 4 ABV = 5.7%

Ingredients

2.5 lbs. (1.1 kg) Rahr 2-row Brewer’s Malt
2 lbs. (0.91 kg) flaked wheat
0.25 lb. (113 g) acidulated malt
3 lbs. (1.36 kg) extra light dried malt extract
1 oz. (28 g) Simcoe® hops (hop stand)
1 oz. (28 g) Mosaic® hops (hop stand)
1 oz. (28 g) Citra® hops (hop stand)
0.5 oz. (14 g) Simcoe® hops (dry hop)
0.5 oz. (14 g) Mosaic® hops (dry hop)
0.5 oz. (14 g) Citra® hops (dry hop)
The Yeast Bay Saison Blend yeast
White Labs WLP644 (Saccharomyces “bruxellensis” Trois) yeast
Omega Yeast Labs OYL-605 (Lactobacillus Blend) bacteria
3⁄4 cup corn sugar (if priming)

Step by Step

Mash the grains in 7 quarts (6.7 L) of water at 150 °F (66 °C). Collect the wort, top up with water to make 5 gallons (19 L) and bring to a boil. Top off to 6 gallons (23 L). Turn the heat off, add the malt extract and stir to completely dissolve. Return the wort to the heat and boil for 60 minutes. Turn the heat off and allow to cool with the lid off until you reach 180 °F (82 °C). Add the hops and allow to steep for 20–30 minutes before fully chilling. Transfer the chilled wort to a fermenter. Aerate and pitch the saison yeast and Lactobacillus of your choice (Brett is optional). Ferment at 73 °F (23 °C) in the primary for about two weeks. Follow the remainder of the all-grain recipe.

Method #2: 100% lacto, Hopped Pasteurization,100% Brett

Jason Yester of Trinity Brewing in Colorado Springs, Colorado was one of the first to approach hoppy sours from the other angle, souring first, boiling with hops, then proceeding to fermentation with Brett and dry hopping. Red Swingline is a masterpiece: Hoppy, fruity, tart, lightly funky.

This second method is inspired by Trinity. I soured my unhopped wort first with a pure culture of Lactobacillus, removing any risk of hop-inhibition. When souring with a pure culture of Lactobacillus, keeping air/oxygen out is not nearly as essential as it is for wild culture (e.g., inoculated with grain). However, for an added measure of precaution I dose with 88% lactic acid to lower the pH to 4.5, which prevents enteric bacteria from growing. The low starting pH also inhibits the enzyme responsible for protein degradation as well, vastly improving head retention.

I used the Omega Lacto Blend for this recipe, but White Labs Lactobacillus brevis would also be a good choice judging from the results of an experiment Matt Humbard and I presented in “Brewing with Lactobacillus: Overview and Evaluation” in the May-June 2015 issue of BYO. I have also heard good results reported with GigaYeast Lactobacillus delbrueckii and GoodBelly probiotic as well, although I haven’t had a chance to use either.

Once Lactobacillus achieves the desired pH drop, transfer the wort back to the kettle and raise the temperature to 180 °F (82 °C) to pasteurize, preventing over-souring. At the same time add hops, allowing them to steep in the sour wort. One study of acid hydrolysis of glycosides in traditional Chinese herbs found the peak at pH of 5 and 104 °F (40 °C), but it is hard to know how well this translates to hops. From there you could ferment with any acid tolerant yeast (see the “Advanced Brewing” column in this issue on page 111), but I chose to go with White Labs WLP648 Brettanomyces bruxellensis Trois Vrai. This strain is the “true” Brett replacement when it was discovered that WLP644 was a wild Saccharomyces and it is known for its wonderfully fruity interactions with hops.

This recipe could be done as a no-boil, but in that case make sure not to hold the wort above 180 °F (82 °C) for the hop stand, or risk DMS (dimethyl sulfide) production. A craft brewer who attempted my no-boil Berliner weisse recipe on his big system reached out to me with DMS issues . . . apparently what works on a small homebrew rig with an immersion chiller did not work out so well when the wort sat at 211 °F (99 °C) for an hour waiting to go through the heat exchanger!

This beer was the clear crowd favorite during my HomebrewCon talk. It had Goldilocks acidity, enough to be sour without being overwhelming. It also had the most tropical character.

Method #2: 100% Hoppy

(5 gallons/19 L, all-grain)
OG = 1.048 FG = 1.009
IBU = 0 SRM = 4 ABV = 5.1%

Tasting Notes: pH = 3.52. Big tropical fruit (pineapple and passion fruit), floral, with some classic-Brett-funk riding the coattails.

Ingredients

7.5 lbs. (3.4 kg) Rahr 2-row Brewer’s Malt
2 lbs. (0.91 kg) flaked wheat
0.25 lb. (113 g) acidulated malt
0.5 oz. (14 g) 88% lactic acid
1 oz. (28 g) Simcoe® hops (pasteurization)
1 oz. (28 g) Mosaic® hops (pasteurization)
1 oz. (28 g) Citra® hops (pasteurization)
0.5 oz. (14 g) Simcoe® hops (dry hop)
0.5 oz. (14 g) Mosaic® hops (dry hop)
0.5 oz. (14 g) Citra® hops (dry hop)
Omega Yeast Labs OYL-605 (Lactobacillus Blend) bacteria
White Labs WLP648 (Brettanomyces bruxellensis Trois Vrai) yeast
3⁄4 cup corn sugar (if priming)

Step by Step

Mash at 150 °F (66 °C). Collect wort and boil for 60 minutes, do not add any hops. Cool the wort to 100 °F (38 °C) and transfer wort to a fermenter. Pitch the Lactobacillus of your choice, and add lactic acid as needed to achieve a pH of 4.4. If you are in a rush, sour as warm as you can reliably hold (up to 115 °F/46 °C), ideally above 80 °F (27 °C). Approximate souring time 1–3 days to reach pH 3.3–3.4. You can measure by taste, but the sweetness of the wort can make acidity seem milder than it will post-fermentation (even though the pH will rise slightly with fermentation and dry hopping). Once the desired acidity is achieved, return the wort to the kettle and heat to 180 °F (82 °C). Once the temperature is reached, turn off the heat and add the hops. Allow them to steep for 20–30 minutes before chilling to 70 °F (21 °C). Aerate and pitch a large starter of Brett (most commercial Brett strains are not packaged at a high enough cell-count to pitch directly). A 3-L starter on a stir-plate for a week should be adequate. Once the gravity stabilizes (two to four weeks), the beer is ready to package. If you are bottling, add the dry hops to the primary fermenter. If kegging, bag and weight the hops (I use new nylon knee highs and glass marbles) adding them directly to the keg during natural conditioning. Aim for 2.7 volumes of CO2.

100% Hoppy

(5 gallons/19 L, partial mash)
OG = 1.048 FG = 1.009
IBU = 0 SRM = 4 ABV = 5.1%

Ingredients

2.5 lbs. (1.1 kg) Rahr 2-row Brewer’s Malt
2 lbs. (0.91 kg) flaked wheat
0.25 lb. (113 g) acidulated malt
3 lbs. (1.36 kg) extra light dried malt extract.
0.5 oz. (14 g) 88% lactic acid
1 oz. (28 g) Simcoe® hops (pasteurization)
1 oz. (28 g) Mosaic® hops (pasteurization)
1 oz. (28 g) Citra® hops (pasteurization)
0.5 oz. (14 g) Simcoe® hops (dry hop)
0.5 oz. (14 g) Mosaic® hops (dry hop)
0.5 oz. (14 g) Citra® hops (dry hop)
Omega Yeast Labs OYL-605 (Lactobacillus Blend) bacteria
White Labs WLP648 (Brettanomyces bruxellensis Trois Vrai) yeast
3⁄4 cup corn sugar (if priming)

Step by step

Mash the grains in 7 quarts (6.7 L) of water at 150 °F (66 °C). Collect the wort, top up with water to make 5 gallons (19 L) and bring to a boil. Add the malt extract and stir to dissolve. Boil for 60 minutes. Follow remainder of all-grain recipe.

Method #3: Dry Hop an Aged Sour

The most straightforward of the techniques, inspired by both Cantillon and New Belgium, is to take a well-aged mixed-fermentation sour beer and dry hop it. I’ve done this with both lambics and Flemish reds with delicious results. You can give the base beer up to 20 IBUs if you are pitching a blend of microbes that includes Pediococcus. The result is a beer with pleasant acidity and low bitterness, so there is no taste clash.

While dry hopping doesn’t add IBUs it can increase perceived bitterness. Essentially any hop variety you enjoy can be added and your dose can be as subtle or aggressive as you would like. Dry hopping for 3–14 days before bottling (or directly in the keg) allows the beer to be ready when the hop aromatics are still bright and fresh. As an added bonus, if stored at cellar temperature the Brettanomyces will scavenge oxygen, allowing the hop aroma to continue evolving.

For me, this is a perfect example of why a deep cellar of sours is invaluable. I wouldn’t set out to brew a dry hopped sour with this process. For me, this is one solution for what to do when a sour beer isn’t perfect as is. Blending is always an option, but sometimes a complementary match isn’t available. If a beer is bland and not sour enough, I add fruit for the aromatics, as well as the acids and sugars from the fruit helping to lower the pH. I dry hop when the beer is bland and too sour; the hops add interest to the nose, and raise the pH. However, dry hopping is not a solution for a beer with potent off-flavors like assertive acetic sharpness, or associated ethyl acetate (nail polish remover).

If you don’t want to commit to an entire batch, consider bottle hopping a six-pack! Add two or three whole hop cones (no pellets please!) per bottle before filling with primed beer. Once it is carbonated, prepare to enjoy by chilling the beer for at least one day before opening. When you are ready to open, set a tea strainer in an oversized glass and pour the beer immediately upon opening. The hops provide nucleation sites for CO2 bubbles to form.

The recipe on page 70 is a scaled down version of the beer that Nathan Zeender and I brewed to fill a 61-gallon (230 L) wine barrel in my basement. Each year we pulled 20 gallons (76 L) splitting four ways: Plain, fruit, wildcard, and dry hopped. Then we would refill with fresh beer to restart the aging. More information about what we did can be found in “Blending Sour Beers with the Solera Method” in the May-June 2014 issue of BYO.

Method #3: Hoppy So[ur]lera

(5 gallons/19 L, all-grain)
OG = 1.061 FG = 1.004
IBU = 10 SRM = 4 ABV = 7.5%

Tasting Notes: pH = 3.27. Big sour-orange rind nose, sharp lactic acid (with a hint of acetic), finish is a bit juicy (softer than the nose suggests). Hops are the mildest of the three, despite the highest dry-hopping rate!

Ingredients

6 lbs. (2.7 kg) Pilsner malt
4.4 lbs. (2 kg) American pale malt
15 oz. (0.43 kg) quick oatmeal
13 oz. (0.37 kg) flaked wheat
10 oz. (0.28 kg) wheat malt
2.8 AAU Willamette hops (60 min.) (0.75 oz./21 g at 3.7% alpha acids)
1 oz. (28 g) Simcoe® hops (dry hop)
1 oz. (28 g) Mosaic® hops (dry hop)
1 oz. (28 g) Citra® hops (dry hop)
1-2 oz. (28-57 g) medium toast French oak cubes (optional)
East Coast Yeast ECY01 (BugFarm) blend
3⁄4 cup corn sugar (if priming)

Step by Step

Mash at 158 °F (70 °C). Collect wort and boil for 60 minutes, adding hops as scheduled. Cool and transfer wort to a fermenter. Aerate and pitch the souring yeast blend of your choice and/or bottle dregs from your favorite unpasteurized sour beers. Ferment at 67 °F (20 °C). Approximate fermentation time in primary fermenter is one year. We aged the original in a barrel, so 1–2 oz. (28–57 g) of medium-toast French oak cubes could be added.

Once the gravity stabilizes, the beer is ready to package. If you are bottling, add the dry hops to the primary fermenter. If kegging, bag and weight the hops (I use new nylon knee highs and glass marbles) adding them directly to the keg during force carbonation. Either way, aim for 2.7 volumes of CO2.

Hoppy So[ur]lera

(5 gallons/19 L, partial mash)
OG = 1.061 FG = 1.004
IBU = 10 SRM = 4 ABV = 7.5%

Ingredients

3 lbs. (1.36 kg) Pilsner dried malt extract
1.5 lbs. (0.68 kg) extra light dried malt extract
2 lbs. (0.91 kg) American pale malt
15 oz. (0.43 kg) quick oatmeal
13 oz. (0.37 kg) flaked wheat
10 oz. (0.28 kg) wheat malt
2.8 AAU Willamette hops (60 min.) (0.75 oz./21 g at 3.7% alpha acids)
1 oz. (28 g) Simcoe® hops (dry hop)
1 oz. (28 g) Mosaic® hops (dry hop)
1 oz. (28 g) Citra® hops (dry hop)
1-2 oz. (28-57 g) medium toast French oak cubes (optional)
East Coast Yeast ECY01 (BugFarm) blend
3⁄4 cup corn sugar (if priming)

Step by Step

Mash the grains in 6.5 quarts (6.2 L)of water at 150 °F (66 °C). Collect the wort, top up with water to make 5 gallons (19 L) and bring to a boil. Turn the heat off, add the malt extract and stir to dissolve. Top off to 6 gallons (23 L). Return the wort to the heat and boil for 60 minutes, adding the hops as scheduled. Cool and transfer wort to a fermenter. Aerate and pitch the souring yeast blend of your choice and/or bottle dregs from your favorite unpasteurized sour beers. Ferment at 67 °F (20 °C). Approximate fermentation time in primary fermenter is one year. We aged the original in a barrel, so 1–2 oz. (28–57 g) of medium-toast French oak cubes could be added.

Once the gravity stabilizes, the beer is ready to package. If you are bottling, add the dry hops to the primary fermenter. If kegging, bag and weight the hops (I use new nylon knee highs and glass marbles) adding them directly to the keg during force carbonation. Either way, aim for 2.7 volumes of CO2.

Other Techniques

Here are three other methods that you might consider:

QuiCK Mixed-Fermentation

There is no reason that a dry hopped mixed-fermentation sour has to be long-aged if you have the right combination of culture and temperature. Nathan Zeender, my friend and occasional BYO co-writer, brews a few dry hopped sours at Right Proper Brewing Co. in Washington, DC. He leaves hops out of the boil, although he sometimes adds herbs or citrus. Post-boil he chills the wort to 110 °F (43 °C) and pitches a house Lacto blend. It is not until after fermentation/souring are complete that he dry hops. The luxurious beer, called Diamonds, Fur Coats, Champagne, is flavored with grapefruit zest and elderflowers, then dry-hopped with Hallertau Blanc. Kick Kick Snare is dry hopped with Citra® and Cascade for a “intensely acidic and juicy experience.” I borrowed some of the house culture to ferment a 4% ABV sour beer with 5% quinoa for body, dry hopping with 007: The Golden Hop™ and the zests from three grapefruits — the result wasn’t far from grapefruit juice!

Dry Hop to Stop Lactobacillus

Many brewers have welcomed the wider availability of fast and acid-tolerant Lactobacillus species like L. plantarum and L. brevis. Some of these isolates are able to make firmly acidic beer in as little as 18 hours. In some cases, they can be too aggressive if you want to stop at tangy. The remedy is to take frequent pH readings until the target is reached and then pasteurize the beer to halt acidification (as described in method #2). But what happens if it hits the ideal acidity at 10 PM, or right before you head to work? Luckily even without isomerization hops are anti-Lactobacillus!

Once the ideal acidity nears, add your dose of dry hops and pitch brewer’s yeast. As an experiment by Per Buer showed, dry hops will not stop Lactobacillus in their tracks, but they’ll only have a few steps left. What this method lacks in the precision of pasteurization, it compensates with speed and ease. Allow the wort to sour at warm room temperature, rather than heated, to slow the Lactobacillus, buying you more time to catch the acidity at the right moment. Splitting the wort between Lactobacillus and brewer’s yeast is another option; add the dry hops when combining to prevent further acidification.

Blend in Acid Beer

If you have a particularly acidic batch of beer, hold onto it. If you want an acid beer, brew an unhopped low-gravity pale wort with a cool mash pH souring with either Lactobacillus plantarum or L. brevis followed by French saison to dry it out as much as possible. The goal is to achieve a pH close to 3.0 so that you can add considerable acidity without diluting the target.

Then try blending this into either a 100% Brett IPA, or a New England IPA! For a purpose-brewed beer, I would limit hop additions to the whirlpool, even chilling the wort to 185-190 °F (85-88 °C) to reduce bitterness.

Sour beers with both fruit and dry hops are an extension of this topic — luckily I already wrote about it: “Hoppy Fruit Beers & Fruity Hopped Beers” in the July-August 2016 issue of BYO!

Conclusion

If you can’t beat ‘em, join ‘em! As hoppy beers and all things IPA continue to increase in popularity, many brewers are looking for new and interesting ways to incorporate hop aroma — even in sours.

References:

• www.newbelgium.com/community/Blog/new-belgium-brewing/2016/08/25/inside-this-year-s-vintage-of-le-terroir-dry-hopped-sour-ale
• http://aem.asm.org/content/72/10/6483.full
• www.researchgate.net/publication/261763403_Hydrolysis_of_Glycosidic_Flavonoids_during_the_
Preparation_of_Danggui_Buxue_Tang_An_Outcome_of_Moderate_Boiling_of_Chinese_Herbal_Mixture
• www.youtube.com/watch?v=J2g5P7ZlGn4