Spontaneous Beer Blending 2017


Beer samples arranged and ready for evaluation

The "art of blending" is something that sounds magical and mysterious. Blenders of Gueuze talk about contrasting the sweetness of young, 1-year old lambic with the sourness of 3-year old lambic and brewers who produce fruited sour beers (including Lambic brewers) often talk about creating a blend (to which they will add fruit) that is not aggressively sour as the acids within the fruit with create a further perception of "sourness". The term "blending" in these cases refers to a sort of culinary equilibrium between various flavors and or sensations. Much like an artist uses various colors and quantities of paint to create a painting, an experienced blender may use the beers he has available to create something that is more complex than the sum of the individual beers in the blend. On the opposite side of the "Art vs. Science" spectrum is blending for consistency. Many commercial breweries, especially ones with a large distribution footprints, will blend batches of finished beer to maintain consistency in their packaged product. While many craft beers fans will turn their nose up at any mention of (insert brand of macro lager here), their ability to maintain consistency and stability in their product is nothing short of impressive. As a casually scientific homebrewer, I find myself favoring the artful side of blending. However, I do try to take thorough notes and acquires as many data points as possible. In this post I will walk through my thought process and execution of what I would consider my first major beer blending session.


Carboys of spontaneous beer ready to be sampled

I was looking forward to December 2017 ever since I brewed my first batch of Lambic-inspired beer, Batch 1, in July of 2014. I spent three long years patiently waiting, occasionally sampling, and annually adjusting my spontaneous beer recipe and process. For this blended spontaneous beer, I was hoping to be somewhere in the ballpark of a traditional Gueuze, but wanted to let the beers I had available for blending guide/dictate what the resulting blend would taste like. I had been using my local ambient environment to inoculate the beers and had used some local ingredients, so letting the blend tell a unique story about where it came from was the main goal of the blend.

I had been collecting green bottles for years just for this occasion, and as the months of 2017 passed, I began to go over the logistics of the upcoming blending session in my head. I had assumed that I would be using between 3-6 gallons of beer from each spontaneous season so my bottling volume would be somewhere between 9-18 gallons. I determined a 1/2BBL (15.5gallons, 56.8L) sanke keg would serve me well as a blending tank as I only had 3 gallons left from the 2014 season so my maximum bottling volume was ~15 gallons. After acquiring and thoroughly cleaning a 1/2BBL keg, I did a practice bottling run in the blending tank with 12 gallons of red sour beer that I blended from my 3 red sour soleras. In this case, I primed the entire batch in the blending tank and bottled directly from it, using a stir plate to keep the solution evenly mixed. However, it didn't keep everything mixed as well as my standard bottling bucket setup. For this reason, I chose not to bottle the spontaneous beer directly from the blending tank. Instead, I planned on racking the selected beers into the blending tank and letting them rest for 24-48 hours. Then I would fill a standard 6-gallon bottling bucket from the blending tank and prime according to the volume graduations on the side of the bucket.

Hydrometer with dental floss for easy removal

Another logistical dilemma I was facing was how to pull samples and acquire pH and SG data for every beer without removing a significant amount of liquid from each carboy. I would be selecting from 1, 2, and 3-year old spontaneous beers with some of them potentially being sampled up to 3 times over a period of two to three years. If I pulled out enough beer to fill a hydrometer test jar each time, I would slowly be increasing the head space in the 3 and 6-gallon carboys which is something I was working hard to avoid. Ultimately, my solution was to suspend a final gravity hydrometer directly in each carboy and read the hydrometer through the glass carboy. I would tie dental floss to the hydrometer so that it could simply be lifted out of the carboy and re-sanitized. For pH measurements I didn't have to think quite as hard. My Milwaukee MW102 pH meter has probes with long leads so I planned to sanitize the probes then lower the sensors into each carboy by holding the sensor leads. I would then remove and re-sanitize the sensor leads following every measurement.

Sticking with tradition for spontaneous beers and Lambic, I chose to only use green bottles and finish them with a cork and cage. I had recently read a post on facebook by Mitch Ermatinger of Speciation Artisan Ales where he detailed a method for corking and caging where the cork is inserted only part way into the bottle. The cage would then be loosely placed over the cork and the entire bottle placed in a bench capper. The bench capper would then be used to compress the cork, manually forming the mushroomed top, as well as insert the cork into the bottle a little further. While the cork was still compressed in the bench capper, the cage would then be closed. When removed from the capper the final result is a cork that is firmly compressed in place and much easier to remove from the bottle.

The final logistal concern I had was priming the blended beer. I was a bit nervous as I had never done a blend using 1, 2, and 3 year old beers. I had assumed that the 3 year old beer would be considerably less carbonated than the one year old beer held at the same temperature simply due to the amount of time that it had to off gas any CO2 in solution but I didn't have access to a Zahm & Nagel (or other similar device capable of measuring carbonation) to verify this. As an alternative, I chose to rely on the Blending Calculator found on the Bikes, Beer and Adventures blog. This calculator uses parameters such as OG, FG, pH, peak temperature, volume of each blend component, and more to calculate the final parameters of the blend and ultimately determine how much priming sugar is required to reach the target volumes of CO2 in the final product. Additionally, I chose not to add any priming yeast since, in my opinion, a spontaneous beer should never have yeast pitched at any point. It was a significant risk, but keeping with tradition was important to me so I bit the bullet. With a solid game plan in place, it was time to acquire my final data points that I would use to create my first spontaneous beer blend.

Recipe Specifications

My recipe for this particular spontaneous beer has evolved over time. For specific details on each beer, use the "Batch X" hyperlink in each section below to navigate to the page that contains recipe information for that particular batch.


An unusually heavy pellicle on one of my spontaneous beers
A typical pellicle on my spontaneous beers

The data below was collected on December 10, 2017 using the methods described in the Approach section above. 

Beer #1 - 2016 oak inoculated, Batch 4, 3-gallon carboy
SG: 1.000   pH: 4.40
Aroma: Low aged hops, malty wort, earthy
Flavor: Medium-high floral, medium aged hops, medium worty, medium bitterness
Mouthfeel: Medium body, no astringency

Beer #2 - 2016 spontaneous, Batch 4, 6-gallon carboy
SG: 1.002   pH: 4.29
Aroma: Low peach skins, earthy
Flavor: Medium floral/spicey hops, medium bitterness
Mouthfeel: Medium body, low acidity

Beer #3 - 2016 spontaneous, Batch 4, 1-gallon carboy
SG: assumed same as Beer #3   pH: assumed same as Beer #3
Aroma: assumed same as Beer #3
Flavor: assumed same as Beer #3
Mouthfeel: assumed same as Beer #3

Beer #4 - 2015 spontaneous, Batch 3, insulated coolship, 6-gallon carboy
SG: 1.002   pH: 3.53
Aroma: Medium-low peach, low clean malt, low aged hops, low acidity
Flavor: Medium-low peach, low aged hops
Mouthfeel: Medium-light body, medium acidity

Beer #5 - 2015 spontaneous, Batch 3, insulated coolship, 3-gallon carboy
SG: 1.006   pH: 3.58
Aroma: Medium-low peach, very low aged hops, low acidity
Flavor: Medium Lemon, medium low oak
Mouthfeel: Medium-light body, medium acidity

Beer #6 - 2015 spontaneous, Batch 3, un-insulated coolship, 6-gallon carboy
SG: 1.014   pH: 3.32
Aroma: Medium funky-rotten vegetables, medium-low aged hops, very low peach skin
Flavor: Medium lemon/pine, low peach skin
Mouthfeel: Medium body, high acidity

Beer #7 - 2014 lambic blend, Batch 2, 6-gallon carboy
SG: 1.009   pH: 3.56
Aroma: Medium bready malt, medium malty wort, brothy
Flavor: Medium brothy, low aged hops
Mouthfeel: Medium-light body, low acidity

Beer #8 - 2014 spontaneous, Batch 2, 3-gallon carboy
SG: 1.008   pH: 3.51
Aroma: Medium malty wort, low peach skin, low lemon
Flavor: Medium-low bready malt, low aged hops
Mouthfeel: Medium body medium-low acidity

With these data points now acquired, I did have a few restrictions that needed to be considered while blending. Firstly, I needed to select some amount of 1, 2, and 3 year-old beers for blending. Beer #8 was the only 3-year old 100% spontaneous beer that was available for blending, so I had committed up front to using all 3 gallons of that beer in the final blend if needed. I also did not want to be left with small portions of a carboy so I planned on using either half or all of each 6-gallon carboy and all of each 3-gallon carboy. My real decisions came down to which of the 1 and 2-year old beers I would use in the blend and at what proportions. My first cut at the blend was as follows:

Blend #1
3-year, Beer #8, 25%
2-year, Beer #6, 25%
1-year, Beer #2, 50%
This blend presented medium peach and medium aged hop flavor, medium bitterness and medium acidity. I chose to continue blending by switching up the 2-year old portion a bit.

Blend #2
3-year, Beer #8, 20%
2-year, Beer #5, 20%
2-year, Beer #6, 20%
1-year, Beer #2, 40%
Blend #2 was noted to be more peach forward than Blend #1 and had a balanced acidity and bitterness. Blending continued by again switching up the 2-year old portion.

Blend #3
3-year, Beer #8, 20.6%
2-year, Beer #4, 37.9%
1-year, Beer #2, 41.5%
Inital impressions with Blend #3 were that it was similar to Blend #2 except the bitterness was slightly forward of the peach.

I decided at this point to take a break to give my palate a rest and then come back to do a showdown between my two favorites, Blends #2 and #3. After a glass of water, I re-evaluated my two remaining candidates and determined that Blend #3 to be my final choice due to my perceiving it as being more peach forward that Blend #2. Blend #2 was now presenting itself as more floral and bitter forward when compared to Blend #3. With my final blend determined I now had to plan the bottling day.

However, the day after my blending session presented a substantial delay in my plan, as I discovered that my Dad had passed away. In my early 20's he had introduced me to craft beer, sharing with me some of his favorites such as New Belgium's Tripel and Boulevard's Tank 7. He also taught me to homebrew (along with numerous other useful life skills) and after showing me the ropes a few times, I purchased all of his brewing equipment from him and ventured out into the wide world of all-grain brewing on my own. Following his passing, I was able to acquire brewing notes from my Dad's brewing partner from back in the 90's. I am planning to recreate at least one of their beers sometime in the near future, possibly with hops that I have grown on my own "farm" here in Neosho, MO.

On February 3, 2018, I was finally able to find time to blend the selected beers into my cleaned and sanitized blending tank (1/2BBL keg). Using the Blending Calculator mentioned above, I determined that the entire 14.5-gallon blend would need 16.07oz. (455.6g) of priming sugar to achieve my target of 3.2 volumes of carbonation. The calculator also determined the final parameters of the blend as follows:

Blend #3
ABV: 6.71%
FG: 1.003
pH: 3.71

Blending Calculator with data populated

I left the blended beer in the blending tank for a full week before priming and packaging in three separate steps. I accomplished this by racking from the blending tank into a bottling bucket with volume graduations. I then used the volume measurement to determine the priming rate as a percentage of the priming sugar needed for the entire blend. For example, the first bottling was 6 gallons.

6 gallons / 14.5 gallons = 0.4137 or 41.37% of the total
16.07oz. * 0.4137 = 6.65oz. (188.5g)
Therefore, 6.65oz. of priming sugar was needed to to prime the 6-gallon portion of the blend.

After what seemed like a lifetime supply of 750mL and 375mL green bottles had been thoroughly de-labeled, cleaned, and sanitized I bottled the entire batch with the corking method described above. I had recently purchased an Italian floor corker and had not yet used it for this corking method, or any other for that matter. I quickly found out that the metal opening in the corker I had purchased wasn't large enough for an uncompressed cork to pass through so I decided to increase the diameter of the opening with a tapered drill bit. After corking was completed I went back through all of the bottle and used the method described above to manually mushroom the cork and close the wire cage. At this point I took a tally and had (55) green 750mL bottles and (33) green 375mL bottles. It gave me a sense of pride to step back and look at those 88 bottles that I had been working towards filling for the last 3-1/2 years, but there was still a possibility that the beer might not carbonate. I had to be patient.


May 20, 2018 - 3-1/2 months in the bottle

On April 2, 2018 I opened the first bottle and was ecstatic to hear the cork pop and see a foggy blanket of CO2 rising from the mouth of the bottle. I felt a little bit like Dr. Frankenstein as I maniacally shouted, "It's alive!" It was incredibly satisfying to see that my hard work and patience had finally paid of. The beer overall presents itself as being bitter, floral, and funky. There is a lack of acidity to this, and all of the individual spontaneous batches I have brewed so far, that I have recently attributed to over-hopping the wort. It is so bitter and the acidity is so low that I don't think it is fair to describe this blend as Gueuze-inspired or Lambic-inspired beer as I would personally find that pretty misleading. Given my intentions to create a beer that told a story about the region it came from, I will likely label these bottles as being an Ozarkian Spontaneous Ale, as they were born here in the Ozarks.

Looking back at my initial notes for Blend #2 and #3 I am wondering if I didn't get the two mixed up in evaluation as the finished beer ended up tasting more like how my notes described Blend #2. As time goes on I will check back in and append some updates as these beers evolve in the bottle.


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