Developing House Sour Cultures – A Bioreactor Approach

Posted on August 16, 2015 by Nick Ladd

Previously I've been keeping my house sour culture refreshed with frequent feedings of starter wort.

I have typically been keeping my house sour culture refreshed with frequent feedings of starter wort.

Over the past couple of years, I’ve cultured and grown up bottle dregs from a variety of commercial sour beers to complete several different projects. These dregs are a great way to add biodiversity to the commercial blends (like Roeselare) that I typically start a sour beer with and tend to produce a more interesting final product. As I acquired these cultures, I began combining them with the intent of developing a variety of house-mixed cultures of bacteria and yeast that I can maintain and use to completely ferment out sour beers. The intent is to continue shaping these mixed cultures until they get to the point where they can consistently produce quality sour beer in a predictable time frame. I fully expect the blend of microbes within the culture to drift, but hope an eventual homeostasis will take hold within the culture. Currently, I have built three different mixed cultures around a spectrum of cultured microbes harvested from commercial beers.

One of the biggest tasks in maintaining a culture like this is the frequent feedings required to keep a culture viable. The idea of maintaining my cultures through periodic feedings of fresh wort that would eventually provide the steady byproduct of sour beer seemed like a great idea. And so, the idea of a sour culture bio-reactor was born. The idea is pretty basic. I’ve put together a schedule of brew days that in theory will consistently provide nutrition for the culture as well as produce a steady stream of sour beer for evaluation. Every four months I brew a different 3-gallon batch of moderate gravity wort that gets split three ways to feed one gallon of fresh wort to each of my three mixed cultures. On brew day I transfer the previous batches of now fermented beer off the culture to a clean glass aging vessel where it will continue to develop for another 8 months (1-year total fermentation time) before packaging. The cultures are then transferred to the freshly brewed wort for a new round of fermentation. After the initial one-year cycle, the bioreactor will consistently output three, 1-gallon batches of sour beer every four months. The beauty of running three cultures in parallel with the same wort is that I’ll be able to compare side-by-side the impact each different culture has on the finished product. My hope is to experiment with different grain bills to better understand the interrelationship between grain bills, mash temperatures, and mixed culture fermentation.

I initially started this project using a single mixed culture. To date, this culture has been through 3 generations of wort. I’ve tasted the first two generations (currently 4-months and 8-months old) and the results have been pretty outstanding; and consistent within the limited sample thus far. I’m optimistic that with some luck and diligence I’ll be able to shape these cultures to the point that they produce sour beer that is both delicious and unique to my brewery.

The first round in the bioreactor ready for fermentation. The initial recipe was 90% Pilsner, 10% Carapils, and had a starting gravity of 1.054.

Cloning Sierra Nevada Pale Ale

Posted on July 8, 2015 by Nick Ladd

Somehow, I’ve managed to never make a true attempt at cloning a commercial beer. This is somewhat regrettable as attempting to reproduce a reliably consistent commercial product is an opportunity to not only test your process controls, but also gain a true understanding of how certain ingredients and techniques can impact a final beer. Personally, no beer would be better for a clone attempt than Sierra Nevada Pale Ale. Not only is this a beer that was very formative in my journey towards craft beer, it is also reliably available, fresh, and consistent.

Sierra Nevada Pale Ale on the left, homebrewed beer on the right.

The first step is researching the beer you’re trying to clone and establishing a set of specifications for that beer. In the case of Sierra Nevada Pale, their website provides a good starting point in terms of gravities, bitterness, and base ingredients. From there, a number of other websites and forums provide additional anecdotal stories and recipes that can inform your own formulation. With the research complete, I formulated the following recipe.

Sierra Nevada Pale Ale Clone Attempt (not Cloned)

Specifications:

Size: 3.25 gal
Efficiency: 68%
Attenuation: 75% (measured)

Original Gravity: 1.053
Terminal Gravity: 1.013 (measured)
Color: 11.79 SRM
Alcohol: 5.1% ABV (calculated)
Bitterness: 38.2 IBU (calculated)

Grist:

6.75 lb (93.1%) Briess 2-Row Brewers Malt
8 oz (6.9%) Muntons Crystal 60L

Mash Regiment:

153 °F – Sacc Rest – 30min

Water Treatment:

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

Hopping:

9 g Magnum (12.6% AA) – 60 m
8 g Perle (8.7% AA) – 30 m
8 g Cascade (6.9% AA) – 10 m
26 g Cascade (6.9% AA) – Whirlpool 15m

Kettle Additions:

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

Yeast:

WYeast 1056 American Ale™ Starter on stirplate to achieve 1 million cells per milliliter of wort per degree Plato. Use Mr. Malty to determine proper starter sized based on age of yeast package. Pitch into 60°F wort and allow to free rise to 64°F. As fermentation begins to slow, raise temperature to 70°F.

The Results

An important part of the cloning process is a critical review that involves consuming the beer side-by-side with the original, preferably blindly. This allows you to note critical differences which can be projected out to future recipe iterations. Unfortunately, my first attempt clearly did not result in a clone. This however is not a failure, as it allows me to make process and recipe changes to hopefully create a clone in future iterations. Below I’ve outlined the critical differences between my beer, and commercially available Sierra Nevada Pale Ale and the changes I plan to incorporate into the next version of the beer.

Aroma:

The homebrew version of the beer has far more yeast character than the commercial beer. Specifically, my beer has a distinct floral and fruity ester (pear and berry) not present in the commercial beer. In future iterations, I plan to pitch a larger starter and provide additional oxidation of the wort to discourage the production of yeast esters.
The commercial beer has a brighter grapefruit pith and slightly herbal hop aroma. I plan to dramatically increase the whirlpool addition of cascade hops in my beer.
The homebrewed beer has a distinct dark fruit, dark caramel malt aroma. My original intention was to stick with American crystal malts, but was forced to substitute out British crystal malts due to availability. This had a huge impact on the final beer. I will stick to American maltsters in the next iteration.

Appearance

My beer appears a shade darker than the commercial beer. My beer has better head retention than the commercial beer. In the next recipe iteration, I will dial back the amount of crystal malt to lighten up the beer color.

Flavor

Again, my beer has a much richer, darker crystal malt character. This is the by-product of using British crystal malt. The choice of crystal malt made an enormous difference in the final beer. For the next version, I will stick to American maltsters.
My homebrewed version is lacking in the fresh cascade hop grapefruit pith flavor. I will dramatically increase the Cascade whirlpool addition in the next iteration of this recipe.
My homebrew is sweeter than the commercial version. The commercial beer attenuates to approximately 79% apparent attenuation. My version only attenuated to 75%. I will mash lower for the next version of the recipe to attempt to further dry out the beer.
Sierra Nevada Pale Ale has a slightly grainy / tannic finish. This is likely a byproduct of high levels of sugar extraction. I will attempt to boost my extract efficiency for the next version of the beer.
My homebrew is less bitter than the commercial version. Increasing my whirlpool additions should bring the beer closer in line with the commercial version.

Eisbock Homebrew Recipe & Review

Posted on July 1, 2015 by Nick Ladd

Eisbock: Silver Medal in Category 5 Bock at the final round of the 2015 National Homebrew Competition

In many ways, contemporary American craft beer is constantly chasing extremes. Extreme hops, malt, and alcohol are the norm. Eisbock can be seen as one of the original ‘extreme’ beers. It predates the American craft beer movement, but is equally as intense and flavorful as some of the most coveted craft beers. Eisbock manages to maintain a smooth lager character while being a showcase for the intense malt flavors inherent to many of the great German malts.This recipe has done well in competition, winning a silver medal in the Bock category at the final round of the National Homebrewer Competition in 2015.

The myth of eisbock is that it owes its origin to a brewer who inadvertently left a barrel of dopplebock outside in the winter which led to the freeze concentration of the nectar inside. True or not, the science is sound and methodology similar to what I used for this beer. Alcohol inherently freezes at a much lower temperature than water. This trait can be exploited by brewers, allowing them to effectively concentrate the alcohol in their beers while discarding some of the water content.

When designing an Eisbock, my intent was to specifically formulate a base doppelbock that would be lean on caramel character in order to avoid a cloying sweetness once the flavors are intensified during freeze-concentration. Additionally, I wanted to keep the IBUs low as it is has been my experience that freezing a beer will concentrate the bittering compounds. The same logic can be applied to alcohol heat. Providing for a healthy fermentation is key to avoiding excessive fusel alcohols which will be concentrated in the final beer. My focus was on creating rich toasty notes with a solid Munich malt base while including a touch of high lovibond caramel to throw in a bit of dark fruit flavor that is delicious in these types of beers.

Utilizing C02 and a jumper line to transfer beer keg to keg during the freeze-concentration.

The trick to doing this beer correctly is in the freeze-concentration. I went through approximately 8 freeze cycles utilizing two 3-gallon corny kegs and my kitchen freezer. The basic methodology is to freeze a keg of the beer and then push out the remaining unfrozen liquid to a second keg. It is extremely important to use closed vessels purged with CO2 in order to minimize any risk of oxidizing the beer. Patience is key; multiple incremental freezes that only push a small volume of liquid at a time will help insure you’re pulling out the most concentrated liquid. In the end, I pulled out approximately 32% of the original volume. The liquid that was discarded typically had a specific gravity of near 1.000 meaning that it was primarily water. Sensory analysis of the discarded liquid confirms that it was primarily water. This freeze concentration effectively took my ABV from approximately 7.5% to over 11%.

Eisbock Recipe

Specifications:
Size: 3.25 gal
Efficiency: 74%
Attenuation: 68%

Original Gravity: 1.084
Terminal Gravity: 1.026 (measured)
Color: 18.88 SRM (Before Freeze)
Alcohol: 7.5% ABV (Before Freeze. Approximately 11% after freeze.)
Bitterness: 22 IBU (Before Freeze)

Malt Bill:
7.5 lb (68.2%) Weyermann Munich TYPE II
3 lb (27.3%) Weyermann Pilsner Malt
2 oz (1.1%) Weyermann Caramunich® TYPE III
6 oz (3.4%) Hugh Baird Crystal 130

Mash Profile:
148°F – 60m
155°F – 15m
168°F – 5m

Decoctions used between each step.

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

Hopping:
0.75 oz Hallertauer Mittelfrüher (4.0% AA) – 60 m
0.5 oz Hallertauer Mittelfrüher (4.0% AA) – 10 m

Kettle Additions:
0.5 ea Whirlfloc Tablets (Irish moss) – added during boil, boiled 15 m
0.5 tsp Wyeast Nutrient – added during boil, boiled 10 m

Yeast:
White Labs WLP833 German Bock Lager

Tasting Notes:

Judged as a BJCP 5D. Eisbock

Aroma (10/12):
Rich and decadent malt fills your olfactory nerves. The malt is toasty and reminiscent of heavily browned bread crust. There is a background of rich dark caramel providing additional complexity. Enticing aromas of dark fruit, plum, fig, and perhaps cherry waft from the glass. As it warms, a bit of ethanol is apparent and true to the style.

Appearance (2/3):
Deep brown with only the slightest of tan heads that quickly dissipates. Beer is nice and clear due to the prolonged lagering period.

Flavor (17/20):
Huge display of rich malt. There is some residual sweetness that manages to be kept in balance by some intense toasty, almost drying, malt notes. The malt is wonderfully complex with a round nuttiness, followed by fig, molasses, burnt sugar, and sourdough toast. There is just a hint of hop bitterness and no flavor. Fermentation character is clean with a low level of hot alcohol. No ester or other fermentation character.

Mouthfeel (4/5):
Silky full-body with a smooth medium-low level of carbonation. Mouthfeel is just a touch sticky, but otherwise quite luscious.

Overall Impression (9/10)
Beautiful showcase of the melanoiden-rich Munich malt that comprises the bulk of the grain bill. Rich and decadent, it would be tough to consume more than a bottle of this at a time. This Eisbock is a great sipper to spend some time with slowly consuming and contemplating the broad spectrum of flavors it contains. The beer would be absolutely delicious paired with a sharply acidic aged cheddar.

Excellent (42/50)

Brambic – Spontaneously Fermented Wild Homebrew

Posted on May 2, 2015 by Nick Ladd

Against what may or may not be good logic, I’ve begun a new sour beer project. My goal is to successfully create a delicious sour beer fermented only from airborne yeast and bacteria. There is something beautiful about the idea of successfully producing a delicious sour beer that reflects the micro-flora present where I live. I love the tangible connection that can be made with world-renowned Lambic brewers who continue to brew traditional spontaneously fermented beers (as well as American craft brewers like Allagash, Jester King, and Russian River). I am keeping this project as wild as possible; I will not be culturing yeast from fruit, grains, bottle dregs, or any other source, rather only what I can capture across the cool evening breeze.

Brooklyn wild. What fermentive creatures lurk in our Gowanus air?

The Internet is full of stories both of success and failure when it comes to truly spontaneous beer. Whenever I attempt a technique that includes a high probability for failure, I try to set as many variables in my favor as possible to get a successful end result. There are no guarantees for success in a project like this, but taking a few simple measures can greatly increase your odds. Using this logic, I decided that running multiple samples and testing their qualities before pitching into a full 2.75 gallon batch of beer was the way to go. This was especially important given the fact that I live an dense urban environment with little vegetation and no fruit bearing trees that could be attractive homes for wild yeast.

My Process

Initially I prepared (3) 8 oz. samples of sanitary 1.030 OG wort and placed them boiling hot into pint sized mason jars. I added 0.3 ml of 88% lactic acid to each sample in order to acidify each below pH 4.5. My goal is to inhibit pathogens from growing in the wort as well as non-pathogenic bacteria that can produce objectionable flavors. Since I would be tasting the wort, I wanted to minimize terrible tasting samples as well as ones that could potentially make me sick.

Each of the three samples were placed around my apartment. One was located on the roof of my building, one in front of an open window at the rear of my apartment, and one in front of an open window at the front of my apartment. Each were covered with a couple layers of cheese cloth to prevent any insects from entering the sample and then left to cool for approximately 24-hours. After 24-hours I fitted each jar with a lid and airlock to create an anaerobic environment, providing control of another variable and putting selective pressure on the organisms growing in the wort.

I completed this experiment in the late fall, which according to American Sour Beers offers the best probability for culturing yeast and bacteria that will have a positive fermentation character.

After approximately one-month, I completed a sensory analysis of each sample (smell and taste). In hindsight, I should have also taken pH and gravity measurements.

Sample A – In Front of Window – Small filmy pellicle. Cabbage, some baby diaper. No apparent alcohol flavor.

Sample B – Outside on Roof – Small filmy pellicle. A couple spots of white fluffy mold. Some alcohol on nose. Light rubbery phenol.

Sample C – In Front of Window – Small filmy pellicle. Cabbage. Some oniony aromas. Pretty sweet, low alcohol.

Encouraged by the initial results, I stepped each into a three new 300-ml sanitary starters. Each were allowed to ferment for another month under airlock.

Sample A – Very sweet. Didn’t appear to ferment much. Clean.

Sample B – Quite sour. Some definite plastic-like phenolics and slight alcohol. Some pleasing barnyard notes.

Sample C – Reminiscent of pickle juice. The most sour. Definite alcohol on nose. Not very pleasant.

After the second round of fermentation, I decided that Sample B (the sample pulled from my roof) was the most pleasing (or least offensive). I pitched it into a fresh 1200 ml starter (also under airlock) and made preparation to brew a full 2.75 gallon batch. For my recipe, I decided on a simple golden grain bill to act as a clean slate for the culture to express itself.

2014 Brambic Recipe

Size: 3.25 gal
Efficiency: 75%
Attenuation: 90% (estimated)

Original Gravity: 1.049 SG
Terminal Gravity: 1.005 SG (estimated)
Color: 3.33 SRM
Alcohol: 5.71% ABV (estimated)
Bitterness: 0.0 IBU

Grist:
4.0 lb (64.6%) Dingemans Belgian Pils
2 lb (32.3%) Briess Flaked Wheat
3 oz (3.0%) Weyermann Acidulated Malt

Mash Regiment:
A turbid mash regiment (basically a thin decoction) was completed through the steps below. A Ferulic acid rest was completed to encourage the formation of 4-vinyl guaicol which Brettanomyces can theoretically convert into 4 ethyl-guiacol which produces some of the ‘funky’ aromas and flavors that Brettanomyces is known for. A short Beta rest was followed by a very high Alpha rest to encourage a dextrinous wort and protracted secondary Brettanomyces fermentation.

113 °F – Ferulic Acid Rest – 10min
136 °F – Protein Rest – 5min
150 °F – Beta Rest – 20min
162 °F – Alpha Rest – 30min
168 °F – Mashout Rest – 5min

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

Hopping:
1.25 oz AGED Cascade (0% AA) – 90 m

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

Yeast:
1200ml Brambic Spontaneous Culture
Fermented at ambient temperatures (70°F or so)

The beer will be allowed to ferment for at least a year until packaging.

2014 Gueuze Brewday

Posted on April 6, 2015 by Nick Ladd

Gueuze is a wonderfully complex sour beer that is typically a blend of 1, 2, and 3 year old spontaneously fermented Lambic batches. While, technically not a Lambic (Lambic is a protected term for a specific type of beer brewed within a specific geographic region of Belgium), this beer is made in the spirit of Lambic. It eschews the typical spontaneous cultures used in traditional Lambic fermentation for a commercial microbe blend (Wyeast Roeselare) combined with grown up bottle cultures.This batch of homebrew marks the my second annual batch of Lambic-style beer that will ultimately become part of a 3-component Gueuze blend that includes 3-year, 2-year, and 1-year old Lambic-style brews.

To further provide variation (and flexibility) in what will ultimately build the blend, I brewed a 3-gallon batch the was split three-ways and inoculated with distinct culture grown up from various bottle dregs: Jolly Pumpkin La Roja, Russian River Framboise for a Cure, and my house bug culture.

To further provide variation (and flexibility) in what will ultimately build the blend, I brewed a 3-gallon batch that was split 3-ways and inoculated with distinct cultures grown up from various bottle dregs: Jolly Pumpkin La Roja, Russian River Framboise for a Cure, and my house bug culture.

2014 Lambic-Style Homebrew Recipe

Specifications:
Size: 4.25 gal
Efficiency: 75%
Attenuation: 90% (anticipated)

Original Gravity: 1.045 SG
Terminal Gravity: 1.005 SG (anticipated)
Color: 3.1 SRM
Alcohol: 5.3% ABV
Bitterness: 0.0 IBU

Malt Bill:
5 lb (66.7%) Belgian Pils (Dingemans)
2.25 lb (30.0%) Flaked Wheat (Briess)
4 oz (3.3%) Acidulated Malt (Weyermann)

113 °F – Ferulic Acid Rest – 10min
136 °F – Protein Rest – 5min
150 °F – Beta Rest – 20min
162 °F – Alpha Rest – 30min
168 °F – Mashout Rest – 5min

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

Hopping:
1.75 oz AGED Cascade (0% AA) – 90 m

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

Yeast:
WYeast 3763 Roeselare Ale Blend – No Starter
Ferment at room temp until activity ceases. Rack into individual 1-gallon fermentation vessels. Inoculate each with separate secondary cultures.