About a 125 years ago when pure culturing techniques were developed it was originally intended to isolate and propagate pure ale and lager yeast cultures for breweries. In the last 10 years an increasing number of breweries have used those same techniques to produce 100% Brettanomyces beers. One brewery, Crooked Stave, is even basing their lineup nearly completely on Brett as a primary fermenter. While Brett is a different genus than brewer’s yeast, it is still yeast. For my most recent batch of Berliner weisse I decided to brew my first yeast-free beer, relying on only bacteria (Lactobacillus).
Lactobacillus is an interesting organism. It is known for its rapid fermentation in dairy products, producing all the required acidity for yogurt in just a few hours at high temperature (115-120 F). The problem with using Lacto is the huge range the genus comprises. For example, the strain sold by Wyeast (5335) is only capable of fermenting about 10-12% of the carbohydrates in a standard wort, not nearly enough attenuation for something resembling beer. Luckily White Labs’ 677 strain is capable of producing an enzyme which allows it to ferment maltose, maltotriose, and raffinose, ensuring a dry finished beer without aid. In addition to lactic acid, WLP677 also produces both alcohol and carbon-dioxide, so the result should be similar to a beer fermented with yeast. Even if my attempt to use this particular strain doesn’t work, it may just mean that I have to find a strain that is better suited for the task.
The confidence to try this technique was inspired by a conversation I had with Tyler King, of The Bruery, while researching my book about American sour beers. He told me that Hottenroth (their Berliner weisse) is fermented almost exclusively by Lacto. There is also a small amount of Brett in their house culture as well, but every time it is plated out the yeast represents a smaller and smaller share of the cells. For early batches it took about two months for reduction of the sulfur compounds to palatable levels, but the culture has adapted and now the beer only takes a month before it is ready for packaging.
The large active starter I pitched produced rapid and energetic fermentation at a warm temperature (pitching close to 100 F). After the start of fermentation I left the fermentor in my basement where the ambient temperature this time of year is around 75 F. I did not apply any additional heat (as I did for the starter). Surprisingly though, after a couple weeks the beer has only minimal tartness. I was hoping to find a way to produce a brightly acidic beer relatively quickly, but the results so far are a bit puzzling. My initial plan was to add a large dose of citrus zest (orange and grapefruit) to the beer as it carbonated (and maybe a touch of citrusy hops) to create a craft shandy. Depending on how the flavor progresses I’ll make a determination on how to proceed.
This batch is yet another test batch for Modern Times Beer. As a result I did away with my usual decoction mash schedule because the necessary equipment isn’t part of the brewery plan. I made a 10 gallon batch, fermenting the other half with my usual combination of US-05, Lacto, and Brett. This will determine if skipping the decoction has a negative affect the final result. If it does, I may need to change from my standard no-boil to a short one as recommended by a number of brewers.
Batch Size (Gal): 11.00
Total Grain (Lbs): 12.75
Anticipated OG: 1.032
Anticipated SRM: 2.4
Anticipated IBU: 1.4
Brewhouse Efficiency: 71 %
Wort Boil Time: 0 Minutes
62.7% - 8.00 lbs. German Wheat Malt
37.3% - 4.75 lbs. German Pilsener
1.50 oz. Czech Saaz (Pellet, 3.00% AA) @ Mash Hop
Safale US-05 Chico
White Labs 677 Lactobacillus Bacteria
Profile: Washington DC
Sacch Rest - 30 min @ 147 F
5/14/12 Made a 2 L starter with 4 oz of light DME and 1/2 tsp of yeast nutrient. Cooled to 115 and pitched a tube of Lacto. Applied a heating pad to keep the temperature warm. First visible signs of fermentation took 24 hours, not bad considering the amount of growth required.
Brewed 5/17/12 By myself
Switched from my usual single decoction to a single infusion to see if the same method would work on the commercial scale. Added pellet hops after doughing in.
Double batch sparged, collected 9 gallons of 1.040 wort. Enough for 11 gallons.
Heated wort to 210 F, then chilled.
5 gallons (including 1 gallon of spring water top-off), 100% Lacto (1 L of starter), pitch at 100 F. Left at ~75 F to ferment. Dry hop with Citra and orange and grapefruit zest? Serve on tap. Mimosa per Shaun Hill ~.5 g/L of zest, which is about 10 g in 5 gallons.
5 gallons standard, chilled to 72 F, topped off with 1 gallon cool spring water to chill it into the high 60s. Pitched 7 g of US-05 and .75 L of Lacto starter. Left at 70 F to ferment.
Good fermentation on both by 24 hours.
Lacto only version blew-off hard at 75 F ambient, clean version waited until after I left and as a result sat open to the air through most of primary. At 65 F ambient.
7/1/12 Pitched about .1 L of Brett Trois starter into normal Berliner weisse and racked to secondary.
7/21/12 Racked the Lacto "only" version to a five gallon secondary.
11/10/12 Bottled 2 gallons of the Lacto-only portion with 2.5 oz of table sugar. Aiming for 3.4 volume of CO2. Racked the rest into keg with the remaining two gallons of the dry hopped wine barrel solera, and .5 oz of whole Comet hops.
12/10/12 Tasting of the blended and dry hopped version.
5/27/13 Tasting of the 100% Lacto version. Solid, but not too exciting. Sourness is lackluster, but otherwise the character of the fermentation is pleasant.
9/22/13 Bottled 2.6 gallons of the "normal" portion with 3.25 oz of table sugar. Aiming for 3.5 volumes of CO2. Racked the rest onto 3.25 lbs of defrosted rhubarb I'd cleaned/chopped/frozen a few months earlier. Originally planned to use it in Dark Saison V, but it was already tart enough.
12/7/13 Bottled the Rhubarb portion, 2.5 gallons, with 3 oz of table sugar. Aiming for 3.4 volumes of CO2.