Article

The Lacto Lounge

Lactic acid-type sour beers (Berliner weisse, Gose, and the like) can be produced by several methods, all of which involve fermentation with at least one bacteria (usually a Lactobacillus species) and at least one yeast strain. The bacteria sours the wort or beer by lowering its pH, and the yeast produces all or most of the alcohol. For brevity, I have divided the methods into three subsets, distinguished by when and how the bacteria and yeast are introduced: Co-pitching/staggered pitching, sour mashing, and kettle souring (the focus of this article).

Co-Pitching or Staggered Pitching: This is a broad collection of mixed fermentation methods, which can involve pitching bacteria (Lactobacillus and/or Pediococcus) and yeast in any order (or together) in a primary and/or secondary fermenter. With co-pitching/staggered pitching, the bacteria normally remains alive throughout the process.

Sour Mashing: In sour mashing, Lactobacillus is introduced to the mash after the conversion of starch to sugars and dextrins is complete. The bacteria metabolize some of the sugars present, producing lactic acid and lowering the pH. The resulting sour wort is then typically run off, boiled (killing the bacteria), cooled, and fermented by a yeast strain.

Kettle Souring: Kettle souring involves inoculating a kettle (or other vessel) of wort with Lactobacillus to sour the wort. The Lactobacillus can come from probiotic drinks or pills, yogurt, fermentation microbe vendors like Wyeast and White Labs, or even from cultures occurring naturally on a handful of base malt. After souring, which can take as little as a day to as long as a week or more, the wort is typically boiled in the same kettle and subsequently cooled and fermented by a yeast strain in a
traditional fermenter.

Kettle Souring Pros and Cons

Because the boil stage of kettle souring kills the souring bacteria, the risk of infecting fermenters, siphons, hoses, airlocks, and any other “cold-side” brewery and serving equipment is greatly reduced, in contrast to co-pitching/staggered pitching. (Sour mashing shares this advantage, but its process is somewhat more difficult to control.) In fact, many commercial breweries getting started in making sour beers choose kettle souring for this reason.

Another significant advantage to kettle souring is that it allows the brewer to hop as aggressively as desired in the boil. Most Lactobacillus species are very sensitive to hop compounds, which inhibit the souring process. By souring prior to the addition of hops in the boil, this problem is completely avoided.

As with most brewing methods, there are tradeoffs: The pros come with cons. Souring in a kettle comes with two main disadvantages. 

First, depending on the kettle design, it can be difficult to keep oxygen and airborne microbes out, which can result in undesirable, oxygen-loving bacteria or wild yeast growing along with the Lactobacillus bacteria pitched. This can especially become a problem if the wort was inoculated with base malt, which can host a variety of microbes. 

Second, with most brew kettles, it’s difficult to maintain a particular desired temperature for the Lactobacillus to work, e.g. 95 °F (35 °C) for Lactobacillus plantarum or 115 °F (46 °C) for some other Lactobacillus species. This can adversely affect both the time required for souring and the makeup of the active culture.

Building a “Kettle” Souring Keg and Enclosure

As a process-oriented brewer, I had set out to discover a way to keep the advantages of kettle souring, while mitigating or eliminating the disadvantages. I soon realized that excluding oxygen and airborne microbes would be a breeze if I were to use a dedicated Cornelius-type keg as a souring “kettle.” The headspace of a wort-filled keg can be purged with CO2, exactly the same way a keg of finished beer can be purged. This would ensure that no airborne microbes would be introduced and that undesirable microbes already in the wort would be at a disadvantage.

The temperature control challenge could be solved by using FermWrap- type heating elements, controlled by one of the many fermentation temperature control units available. This would optimize the temperature for the particular Lactobacillus species being used, putting any other microbes at a disadvantage. But where could I put the controller’s temperature probe for accurate temperature readings? It occurred to me that the keg’s liquid dip tube would not be needed to serve its normal purpose, and could therefore be converted to a thermowell with a small modification. 

I also decided to make a foam box enclosure that could be placed over the keg to provide some insulation, making the heating element’s job easier and more efficient.

PARTS LIST

• Ball-lock Cornelius-type keg
• Stainless steel plug (see later for sizing)
• Gas quick disconnect with spunding valve
• 4 polystyrene foam sheets, 3⁄4 x 141⁄2 x 48 inches (2 x 39 x 122 cm)
• Construction adhesive suitable for bonding polystyrene

EQUIPMENT FOR OPTIMAL USE OF SOURING KEG

– Temperature controller
– FermWrap-type heating element(s)
– CO2 setup (cylinder, regulator, tubing, gas quick disconnect)

The build begins with a standard 5-gallon (19-L) ball-lock Corny keg. For my build, I purchased a new Italian model because I always seem to be running out of my existing keg capacity anyway, but a used keg from your collection would work just as well. The first step, modifying the liquid dip tube to serve as a thermowell, is really the only tricky part of the build. That’s because it requires soldering or TIG welding. In my case, my friend Dave Naugle helped out. (The pictures accompanying this article show the TIG welded version.) Disassemble the keg, then proceed with the
following steps.

1. Construct The Thermowell

Using a Dremel thin kerf cutoff wheel, cut off the end of the liquid dip tube just above or just below the bend (but not “in” the bend), depending on how your dip tube is shaped. The idea is to cut it so that the new length is about half the height of the keg. Square up the cut end with a belt sander. The stainless steel plug should be a sliding fit into the new end of your particular tube. The diameter needed will probably be between 1⁄4–10⁄32 inch. It can be made by turning a piece of stainless steel scrap in a lathe, or perhaps cutting from an unthreaded portion of stainless steel bolt. Solder or TIG weld the plug into the new end. If soldering, use silver solder and a small torch. If TIG welding, perform a fusion weld, then file, sand with 120 grit through 400 grit sandpaper, and finish with coarse to fine Scotch-Brite pads. A lathe will make the filing, sanding, and finishing steps much easier. The dip tube is now a thermowell. Note: Detailed soldering and welding techniques are beyond the scope of this article, but the included information should be sufficient for an experienced welder or solderer.

If the keg you’re using has posts with “permanent” poppets (i.e. they can’t normally be removed for cleaning), you’ll need to force the liquid post’s poppet out (to allow the temperature controller’s probe through later). This can easily be done by placing the post upright on a work surface and tapping the head of the poppet from above with a screwdriver tip and a mallet or hammer. Do not remove the gas post’s poppet. While you still have the Dremel out, it’s also a good idea to cut the keg’s gas dip tube’s length down to about a 1⁄2 inch (1.25 cm). This is optional, but the gas dip tube really only has to be long enough to hold the gas O-ring, and shortening it will increase the usable volume in the keg.

As an alternative to building the thermowell, for those not able to do the welding, the liquid dip tube could be removed and replaced with a rubber stopper with a waterproof thermocouple running through it. However, I believe this would increase the risk of oxygen ingress.

2. Construct the Foam Enclosure

With a utility knife, cut the polystyrene foam sheets into five pieces; four 14.5 x 27-inch (approximately 37 x 69 cm) sides and one 14.5 x 16-inch (approximately 37 x 41 cm) top.  (14.5 inches/37 cm is the width of the sheets I found, which makes it easy to just cut them to length. Slightly different widths are also common. If yours are different, adjust overall dimensions accordingly. If you cannot find them in your local big box store, they can be ordered online from Menards, model number 1632024.) Repeated light scoring at first, followed by “pushing” down with the knife rather than “dragging” it, helps to cut through without fragmenting the foam. Dry-fit the sides together (upright), and place the top over them; this should look like an upright rectangular box, 16 inches wide x 14.5 inches deep x 27.75 inches tall (41 x 37 x 71 cm), with no bottom. An extra pair of hands will be useful here. To help avoid any mistakes, mark each joint with a pencil, ensuring you’ll get the right pieces in the right places once you start bonding the joints. Use construction adhesive to join two adjacent sides together, making sure the two sides are at 90-degree angles to each other, and allow to cure. Add the third and fourth sides in the same way. Then, add the top. If desired, cut a small notch in the bottom of one side to allow the heating element and temperature control probe wires to run through. (Personally, I just set the box on top of the wires when in use. The weight of the foam box is negligible.) Note: Make sure your particular keg and spunding valve doesn’t exceed 27 inches (69 cm) in height before cutting the enclosure’s side pieces to length. If your setup exceeds that height, increase the side pieces’ length accordingly.

3. (Re)Assemble The Keg

Reinstall the newly constructed thermowell in the keg. It goes in the liquid “out” opening, just like it did when it was a dip tube. Don’t forget to reinstall the dip tube O-ring if you happened to remove it before constructing the thermowell. Next, reinstall the liquid “out” post (sans poppet) onto the liquid “out” opening’s threads. You’ll notice a hole where the poppet used to be. Don’t worry; the keg is still air- and liquid-tight. The hole is where you will later insert your temperature controller’s probe and wire. Finish reassembling the rest of the keg as usual.

Using the “Kettle” Souring Keg and Enclosure

The souring keg and enclosure are fairly straightforward to use. Here’s my process:

Clean and sanitize the souring keg just as you would a normal keg. If possible, purge with CO2 and leave sealed for later use.

On brew day, mash as usual, running off 5 gallons (19 L) (or less) of wort. In a brew kettle, heat the wort to at least 180 °F (82 °C) and hold for at least 8 minutes to pasteurize. Chill the wort to a temperature appropriate for the type of Lactobacillus you’ll be using. Add lactic acid to acidify the wort to a pH of about 4.5, if desired. This is optional, but it will give the Lactobacillus a competitive advantage, improve foam retention, and probably accelerate the souring process.

Using a sanitized siphon, pump, or gravity-fed hose, gently transfer the chilled wort to the sanitized souring keg through the lid opening. Avoid aerating the wort. Add your chosen source of Lactobacillus to the keg. Seal the lid and purge the headspace with CO2 (alternately pressurizing via the gas post and burping the keg via the lid’s pressure release valve ring), leaving about 20 PSI of pressure in the headspace after purging. The extra CO2 in the headspace will be slowly absorbed into the wort, but until then it adds extra integrity to the seal.

Wrap the keg with one or two FermWrap-type heating elements, securing them with tape on the ends. Each species of Lactobacillus has an ideal temperature (or range of temperatures) for souring. For example, L. plantarum works great at about 95 °F (35 °C). Some other species work very well in the 110–120 °F (43–49 °C) range. To sour at 95 °F (35 °C) in ambient room temperature, one Ferm-Wrap is sufficient. For higher temperatures, two FermWraps may be needed. Plug the heating element(s) into your temperature controller and insert the controller’s probe and wire into the keg’s thermowell as far as it will go. Plug the controller into an electrical outlet and set the desired fermentation temperature per the controller’s manual. Note: Some temperature controllers (particularly some older analog models) have probes that are too wide to fit into a dip-tube thermowell. Newer, digital models typically have probes that will fit. Three models that I have tested and confirmed will fit are the Johnson A419, the Northern Brewer Dual Stage, and the Keg King MKII. 

Install the quick disconnect with spunding valve, set to about 20 PSI on the keg’s “gas-in” post, and place the Styrofoam enclosure over keg.

Some species of Lactobacillus, known as “homofermentative,” never produce any CO2. Some species, known as “heterofermentative,” always produce CO2. And some oddballs, known as “facultatively heterofermentative” can produce CO2 under certain circumstances. The Lactobacillus species I prefer, L. plantarum, is one of these oddballs. Fortunately, when souring wort (which contains ample glucose), L. plantarum and other facultatively heterofermentative Lactobacillus species produce little or no CO2. And even the fully heterofermentative species seem to finish souring the wort before producing very much CO2. That said, I think the spunding valve provides some peace of mind.

When the sourness, as indicated by pH measurement, has reached the desired level (I like a pH of about 3.5 for Berliner-type beers), transfer the soured wort to your brew kettle, add distilled or reverse osmosis (RO) water (more on this below), boil, cool, aerate, and pitch a Saccharomyces yeast strain in your “clean” beer fermenter per your usual practices.

Volumes, Gravity, and pH

It may have occurred to you, astute reader, that the souring keg limits the volume of wort that can be soured to about 5 gallons (19 L). If you are brewing a 5-gallon (19-L) batch, without much in the way of trub-producing hops, this is not an issue. Simply make sure that the gravity of your pre-soured wort is the original gravity (OG) you’ll want after the boil. Then add an amount of distilled RO water equal to what you expect to boil off to the boil kettle. The result is 5 post-boil gallons (19 L) of the wort of the desired OG. Easy.

But what if we want more than 5 gallons (19 L) of wort post-boil? We can take a cue from the “high gravity brewing” technique used by some commercial brewers, but apply it only at the pre-boil (mash and souring) stages. We just make 5 gallons (19 L) of soured wort of a higher gravity that’s proportional to the desired final volume of post-boil wort. That may sound complicated, but it’s really not. Suppose we want to make 8 gallons (30 L) of post-boil wort, with a gravity of 1.040, or 40 “points.” Divide the desired volume (8 gallons/30 L) by the souring keg capacity (5 gallons/19 L) and you get 1.6.

So 1.6 will be our multiplier. Since we want 40 “points” in the post-boil wort, we need 1.6 x 40 points = 64 points, or a gravity of 1.064 for the 5 gallons (19 L) going into the souring keg. Then, at the boil stage, add distilled/RO water. The amount to add will be whatever is needed (3 more gallons/11 L in this case) to reach the total desired post-boil volume, plus an amount of distilled or RO water equal to what you expect to boil off.

You may be wondering at this point why we’re adding distilled/RO water and not just tap water to increase the volume. The reason is that distilled/RO water has the least impact on the sourness we have worked to achieve, because it barely makes any change to the pH of soured wort. If soured wort were a simple solution of strong acids, we could easily build a model to predict the pH change (increase) to a fair degree of precision. However, soured wort is a complex solution of many compounds and ions buffering against pH changes, and there’s no simple model to predict the pH increase caused by dilution. But the good news is that soured wort is very good at resisting pH change by dilution. I recently measured a sample of soured wort at a pH of 3.49. I double the volume by dilution with distilled water, and the pH did not move. When I tripled the original volume by dilution with distilled water, the pH increased to 3.50, which is an insignificant change and possibly nothing more than noise in the measurement.

Recipes

Below, please check out three sour beer recipes including a Berliner weisse, a Gose, and an experimental sour. Plus there is even a Lacto-fermented hot pepper sauce you can make. A dedicated souring keg, with fermentation temperature control and CO2 purge capability has tons of potential. 

Berlin Smoothie

(5 gallons/19 L, all-grain)
OG = 1.032  FG = 1.005
IBU = 0  SRM = 3  ABV = 4%

This take on Berliner weisse forgoes any hop additions and incorporates two fruits not often seen together in beer, but it works beautifully. The blueberries and pineapple add a lovely deep claret color that’s unclassifiable. The OG above is prior to souring. The FG and ABV include the impact of the fruit addition. The SRM is for the base wort/beer pre-fruit addition.

Ingredients
3.3 lbs. (1.5 kg) German Pilsner malt 
3.3 lbs. (1.5 kg) pale wheat malt
4 lbs. (1.81 kg) frozen blueberries
4 lbs. (1.81 kg) frozen pineapple
Distilled water 
1⁄2 tsp. yeast nutrient (10 min.)
2 Goodbelly StraightShots or 4 Swanson Probiotic L. plantarum capsules
White Labs WLP001 (California Ale) or Wyeast 1056 (American Ale) or SafAle US-05 yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Mill the grains and dough-in, targeting a mash of around 1.5 quarts of water per pound of grain (3.1 L/kg) and a temperature of 150 °F (66 °C). Add lactic acid as needed to target a mash pH of 5.2. Hold the mash at 150 °F (66 °C) for 60 minutes. Sparge or mashout and lauter with enough water to yield a total volume of 5 gallons (19 L) of wort.

Heat wort to 180 °F (82 °C) in the brew kettle and hold for 8 minutes to pasteurize. Chill the wort to 95 °F (35 °C). Transfer the chilled wort to a sanitized, purged souring keg. Do not aerate. Add the Goodbelly shots or the inner contents of the Swanson capsules to the keg. Seal the keg and purge with CO2, leaving about 20 PSI of pressure in the headspace after purging.

Allow the L. plantarum to sour the wort for about 48 hours at 95 °F (35 °C), until the pH drops to about 3.5.

After souring, transfer the wort to a boil kettle and add the amount of distilled water expected to boil off over a 60-minute period. Bring to a boil and boil for 60 minutes, adding the yeast nutrient at 10 minutes remaining.

Turn off the heat and chill the wort to 68 °F (20 °C) or slightly cooler. Transfer the cooled wort to a “clean beer” fermenter and then aerate and pitch the yeast. Ferment at 68 °F (20 °C) until gravity is a few points above terminal.

Thaw and crush the fruit. Rack beer into a secondary fermenter on top of the fruit. Ferment for about a week at 68 °F (20 °C), or until the sugars in the fruit are fermented out.

If bottle conditioning, carbonate the beer to around 2.5 volumes of CO2. If kegging, carbonate as high as 3.5 volumes of CO2.

Berlin Smoothie

(5 gallons/19 L, extract only)
OG = 1.032  FG = 1.005
IBU = 0  SRM = 3  ABV = 4%

Ingredients
3.6 lbs. (1.63 kg) Bavarian wheat dried malt extract
4 lbs. (1.81 kg) frozen blueberries
4 lbs. (1.81 kg) frozen pineapple
Distilled water 
1⁄2 tsp. yeast nutrient (10 min.)
2 Goodbelly StraightShots or 4 Swanson Probiotic L. plantarum capsules
White Labs WLP001 (California Ale) or Wyeast 1056 (American Ale) or SafAle US-05 yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Fill the brew kettle with 5 gallons (19 L) of water. Heat to about 160 °F (71 °C). Turn off heat, add the extract, and stir to dissolve. Heat wort to 180 °F (82 °C) in the brew kettle and hold for 8 minutes to pasteurize. 

Chill the wort to 95 °F (35 °C) and follow the remainder of the instructions in the all-grain recipe.

Tips for success:
If souring in a kettle instead of a dedicated souring keg, flood the kettle headspace (if possible) with CO2 and cover as tightly as possible. Keep the kettle close to 95 °F (35 °C).

You can add lactic acid to bring the wort pH to about 4.5 or lower before pitching the L. plantarum. This will make the job easier for the bacteria and improve foam retention. If you don’t have a pH meter, about 8–9 mL 88% lactic acid per 5 gallons (19 L) of wort (starting at 5.2 pH) will be useful and should get you in the ballpark.

Using more L. plantarum than called for can also accelerate the souring process. Also, fresher L. plantarum will work faster than older L. plantarum.

Leaving 20 PSI of pressure in the souring keg’s headspace after purging helps ensure positive pressure to keep the keg sealed, as most of the headspace CO2 is slowly absorbed by the wort. If you do not have a spunding valve, check the keg’s pressure periodically and if the souring keg’s pressure actually increases (unlikely), bleed some of it off using the pressure relief valve. 

The Saccharomyces fermentation will be somewhat slowed by the acidity of the wort. This is normal. The yeast is operating under less than ideal conditions (low pH), but will get the job done. 

For a more traditional Berliner weisse, hop to 8 IBUs in the boil with any noble hop, skip the fruit addition and the secondary fermentation, and package the beer when it reaches terminal gravity.

Raspberry Gose

(5 gallons/19 L, all-grain)
OG = 1.046  FG = 1.009
IBU = 0  SRM = 3  ABV = 4.7%

The OG is prior to souring. The FG and ABV include the impact of the fruit addition. The SRM is for the base wort/beer: The raspberries will add a beautiful pink/red color that doesn’t fit the SRM scale.

Ingredients
4.7 lbs. (2.13 kg) German Pilsner malt 
4.7 lbs. (2.13 kg) pale wheat malt
5 lbs. (2.3 kg) frozen raspberries
0.75 oz. (21 g) Indian coriander, freshly ground (15 min.)
0.5 oz. (14 g) sea salt (15 min.)
Distilled water 
1⁄2 tsp. yeast nutrient (10 min.)
2 Goodbelly StraightShots or 4 Swanson Probiotic L. plantarum capsules
White Labs WLP001 (California Ale) or Wyeast 1056 (American Ale) or SafAle US-05 yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Mill the grains and dough-in targeting a mash of around 1.5 quarts of water per pound of grain (3.1 L/kg) and a temperature of 150 °F (66 °C). Add lactic acid as needed to target a mash pH of 5.2. Hold the mash at 150 °F (66 °C) for 60 minutes. Sparge or mash-out and lauter with enough water to yield a total volume of 5 gallons (19 L) of wort.

Heat wort to 180 °F (82 °C) in the brew kettle and hold for 8 minutes to pasteurize. Chill the wort to 95 °F (35 °C). Transfer the chilled wort to a sanitized, purged souring keg. Do not aerate. Add the Goodbelly shots or the inner contents of the Swanson capsules to the keg. Seal the keg and purge with CO2, leaving about 20 PSI of pressure in the headspace after purging. 

Allow the L. plantarum to sour the wort for about 48 hours at 95 °F (35 °C), until the pH drops to about 3.5.

After souring, transfer the wort to a boil kettle and add the amount of distilled water expected to boil off over a 60-minute period. Boil for 60 minutes, adding the coriander, sea salt, and yeast nutrient according to the ingredient list.

Turn off the heat and chill the wort to 68 °F (20 °C) or slightly cooler. Transfer the cooled wort to a “clean beer” fermenter, aerate, and pitch the yeast targeting about 200 billion cells. Ferment at 68 °F (20 °C) until gravity is a few points above terminal.

Thaw and crush the raspberries. Rack beer into a secondary fermenter on top of the raspberries. Ferment for about a week at 68 °F (20 °C), until the sugars in the raspberries are fermented out.         

If bottle conditioning, carbonate the beer to around 2.5 volumes of CO2. If kegging, carbonate as high as 3.5 volumes.

Raspberry Gose

(5 gallons/19 L, extract only)
OG = 1.046  FG = 1.009
IBU = 0  SRM = 3  ABV = 4.7%

Ingredients
5.2 lbs. (2.36 kg) Bavarian wheat dried malt extract
5 lbs. (2.3 kg) frozen raspberries
0.75 oz. (21 g) Indian coriander, freshly ground (15 min.)
0.5 oz. (14 g) sea salt (15 min.)
Distilled water 
1⁄2 tsp. yeast nutrient (10 min.)
2 Goodbelly StraightShots or 4 Swanson Probiotic L. plantarum capsules
White Labs WLP001 (California Ale) or Wyeast 1056 (American Ale) or SafAle US-05 yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Fill the brew kettle with 4.95 gallons (18.7 L) water. Heat to about 160 °F (71 °C). Turn off heat, add the extract, and stir to dissolve. Heat wort to 180 °F (82 °C) in the brew kettle and hold for 8 minutes to pasteurize. 

Chill the wort to 95 °F (35 °C) and follow the remainder of the instructions in the all-grain recipe. 

Tips for success:
If souring in a kettle instead of a dedicated souring keg, flood the kettle headspace (if possible) with CO2 and cover as tightly as possible. Keep the kettle close to 95 °F (35 °C).

You can add lactic acid to bring the wort pH to about 4.5 or lower before pitching the L. plantarum. This will make the job easier for the bacteria and improve foam retention. If you don’t have a pH meter, about 8–9 mL 88% lactic acid per 5 gallons (19 L) of wort (starting at 5.2 pH) will be useful and should get you in the ballpark.

Using more L. plantarum than called for can also accelerate the souring process. Also, fresher L. plantarum will work faster than older L. plantarum.

Leaving 20 PSI of pressure in the souring keg’s headspace after purging helps ensure positive pressure to keep the keg sealed, as most of the headspace CO2 is slowly absorbed by the wort. If you do not have a spunding valve, check the keg’s pressure periodically and if the souring keg’s pressure actually increases (unlikely), bleed some of it off using the pressure relief valve. 

The Saccharomyces fermentation will be somewhat slowed by the acidity of the wort. This is normal. The yeast is operating under less than ideal conditions (low pH), but will get the job done. 

For a more tradition Gose, hop to 8 IBUs in the boil with any noble hop, skip the raspberries and the secondary, and package the beer when it reaches terminal gravity.

Mango Habanero Cherry Bomb Sauce

(Approximately 60 fluid oz. (1.75 L) finished hot sauce)

Though not a beer recipe, this hot sauce made with Lactobacillus-fermented hot peppers is another use I have for my “kettle” souring keg. It’s a cleaner tasting alternative to vinegar-based sauces. The fruit adds sweetness that balances the heat. Use this sauce on eggs, burritos, pizza, or your favorite chip or cracker-like delivery vehicle.

Ingredients (day 1)
4 tbsp. corn sugar
1⁄2 Goodbelly StraightShot or 1 Swanson Probiotic L. plantarum capsule
48 fluid oz. (1.4 L) spring water or other dechlorinated water
4 oz. (0.11 kg) orange habanero peppers, sanitized, stemmed and quartered
16 oz. (0.45 kg) cherry peppers, sanitized, stemmed and cut into eighths
5 large cloves garlic, sanitized and crushed
Sea salt

Ingredients (after fermentation)
16 oz. (0.45 kg) mango chunks

Step by Step

Pre-Fermentation Process

Stir together the sugar, the Goodbelly or the contents of the L. plantarum capsule, and water in a mixing bowl. Add the prepared peppers and garlic. Weigh the mixed ingredients (excluding the weight of the bowl) and add sea salt equal to 3% of the other ingredients’ weight, stirring well.

Fermentation Process

Transfer ingredients to souring keg. Seal the keg and purge with CO2, leaving about 20 PSI of pressure in the headspace after purging.

Allow the L. plantarum to ferment the pepper mixture for about 3 days at 95 °F (35 °C) or about a week at room temperature, shaking/swirling the keg daily.

Post-Fermentation Process

Transfer the pepper mixture to a blender and blend until most of the seeds are no longer whole. Pour the contents into a pot and bring to a boil. Reduce heat and simmer until liquid is reduced by about 50%. Transfer to the blender and purée along with the mango chunks. Transfer to the kettle and heat to at least 180 °F (82 °C) and hold for at least 8 minutes. Bottle in sanitized bottles or jars and refrigerate until use.

Tips for success:

If fermenting in a container other than a dedicated souring keg, flood the container headspace (if possible) with CO2 and cover as tightly as possible. Keep the container close to 95 °F (35 °C).

Leaving 20 PSI of pressure in the souring keg’s headspace after purging helps ensure positive pressure to keep the
keg sealed.

If you do not have a spunding valve, check the keg’s pressure periodically and if the souring keg’s pressure actually increases (unlikely), bleed some of it off using the pressure relief valve. 

Don’t worry if your souring keg’s thermowell doesn’t reach all the way down into the pepper mixture. It will still measure the temperature well enough.

This recipe makes a fairly thick, “toothy” sauce that can be poured very controllably without a “shaker” bottle insert. For a thinner sauce, you could skip the “simmer until reduced” step, but you’d need a blender larger than the typical 2-qt. (2-L) size, or would have to split the final purée step into two stages.

This recipe can easily be scaled up, with all ingredients
scaled proportionally, as there is plenty of room in the souring keg. However, the purée steps would have to be split into multiple stages.

As written, the recipe makes a sauce with a “medium” or “medium-plus” heat. For a hotter sauce, increase the habanero peppers and decrease the cherry peppers, while holding the total weight constant. For a smokier, less “citrusy” sauce, substitute red Fresno peppers for the cherry peppers. Finally, try other fruits (raspberries work well) as a substitute for some or all of the mango.

Danny’s RedRum Ruos

(5 gallons/19 L, all-grain)
OG = 1.046  FG = 1.011
IBU = 5  SRM = 13   ABV = 4.6%

The deep red-garnet color from this beer came to existence for a homebrew club Halloween-themed party. While the color could still be achieved with a less malty base grain, it is supposed to add to the fun of the beer. Be sure to go light on the cinnamon, you don’t want to overpower the fruit character . . . think more a berry jelly on toast with a crisp snap from the acidity and hint of cinnamon.

Ingredients
9 lbs. (4.1 kg) Best Malz Red X malt 
1 lb. (0.45 kg) pale wheat malt
1 oz. (28 g) roasted barley (300 °L)
3 lbs. (1.4 kg) frozen raspberries
3 lbs. (1.4 kg) frozen strawberries
1⁄2 cinnamon stick (0 min.)
5 oz. (21 g) dried hibiscus flower (secondary)
1.3 AAU Cascade hops (60 min.) (0.2 oz./6 g at 6.5 % alpha acids)
1⁄2 tsp. yeast nutrient (10 min.)
2 Goodbelly StraightShots or 4 Swanson Probiotic L. plantarum capsules
White Labs WLP001 (California Ale) or Wyeast 1056 (American Ale) or SafAle US-05 yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Mill the grains and dough-in targeting a mash of around 1.5 quarts of water per pound of grain (3.1 L/kg) and a temperature of 150 °F (66 °C). Add lactic acid as needed to target a mash pH of 5.2. Hold the mash at 150 °F (66 °C) for 60 minutes. Sparge, or mash-out and lauter with enough water to yield a total volume of 5 gallons (19 L) of wort.

Heat wort to 180 °F (82 °C) in the brew kettle and hold for 8 minutes to pasteurize. Chill the wort to 95 °F (35 °C). Transfer the chilled wort to a sanitized, purged souring keg. Do not aerate. Add the Goodbelly shots or the inner contents of the Swanson capsules to the keg. Seal the keg and purge with CO2, leaving about 20 PSI of pressure in the headspace after purging. 

Allow the L. plantarum to sour the wort for about 48 hours at 95 °F (35 °C), until the pH drops to about 3.5.

After souring, transfer the wort to a boil kettle and add the amount of distilled water expected to boil off over a 60-minute period. Bring to a boil and boil for 60 minutes, adding the hops, cinnamon, and yeast nutrient according to the ingredient list.

Turn off the heat and chill the wort to 68 °F (20 °C) or slightly cooler. Transfer the cooled wort to a “clean beer” fermenter, aerate, and pitch the yeast targeting about 200 billion cells. Ferment at 68 °F (20 °C) until gravity is a few points above terminal.

Thaw and crush the strawberries and raspberries and place in the bottom of secondary fermenter. Using 1 qt. (1 L) of water, make a hot tea with the dried hibiscus flower.  Add the tea with flowers to the bottom of a secondary fermenter. Rack beer into the secondary on top of the strawberries, raspberries, and hibiscus tea. Ferment for about a week at 68 °F (20 °C), until the sugars in the fruit have fermented out.         

If bottle conditioning, carbonate the beer to around 2.5 volumes of CO2. If kegging, carbonate as high as 3.5 volumes.

Danny’s Red Rum Ruos

(5 gallons/19 L, extract only)
OG = 1.046  FG = 1.011
IBU = 5  SRM = 13   ABV = 4.6%

Beets are added to the extract version simply to replace the red hue contributed by the Red X malt in the all-grain version. You could add them before souring, but I added the beets to the boil instead to maximize color extraction.

Ingredients
4.2 lbs. (2.36 kg) extra light dried malt extract
1 lb. (0.45 kg) Munich dried malt extract
2 medium beets, processed (10 min.)
3 lbs. (1.4 kg) frozen raspberries
3 lbs. (1.4 kg) frozen strawberries
1⁄2 cinnamon stick (0 min.)
5 oz. (21 g) dried hibiscus flower (secondary)
1.3 AAU Cascade hops (60 min.) (0.2 oz./6 g at 6.5 % alpha acids)
1⁄2 tsp. yeast nutrient (10 min.)
2 Goodbelly StraightShots or 4 Swanson Probiotic L. plantarum capsules
White Labs WLP001 (California Ale) or Wyeast 1056 (American Ale) or SafAle US-05 yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Fill the brew kettle with 4.95 gallons (18.7 L) water. Heat to about 160 °F (71 °C). Turn off heat, add the extract, and stir to dissolve. Heat wort to 180 °F (82 °C) in the brew kettle and hold for 8 minutes to pasteurize. 

Follow the souring instructions from the all-grain recipe. After souring, transfer the wort to a boil kettle and add the amount of distilled water expected to boil off over a 60-minute period. Boil for 60 minutes, adding the hops, beets, cinnamon, and yeast nutrient according to the ingredient list.

Turn off the heat and chill the wort to 68 °F (20 °C) or slightly cooler. Transfer the cooled wort to a “clean beer” fermenter, aerate, and pitch the yeast targeting about 200 billion cells. Ferment at 68 °F (20 °C) until gravity is a few points above terminal.

Follow the remainder of the all-grain instructions.

– Recipe by Dave Green 

Issue: October 2019