Fast Lager Experiment: Traditional vs. Quick Fermentation
Many homebrewers avoid making lager styles due to how convoluted and time consuming the process is. In addition to recommendations calling for yeast pitch rates nearly double that needed for ales, step mashing, and extended boil lengths, many believe genuine lager character can only be produced by following an already lengthened cool fermentation stage with an even longer period of cold conditioning. In New Brewing Lager Beer, Greg Noonan advises determining lager duration based on the OG of the beer, allowing one week for every 2° Plato (about 0.008 SG), meaning that a 1.050 OG Pilsner would require nearly 6 weeks of lagering once fermentation is complete. The hesitance of homebrewers is understandable.
I’d brewed a couple lagers using traditional methods, they came out great, but they tied up my fermentation chamber for way too long. So, I began researching the history of lager brewing in an attempt to understand why they required so much time. What I noticed was that many of the methods accepted as convention seemed a direct emulation of those used by traditional lager brewers who didn’t have access to the technology we do today. Rather than adapting, we adopted, ignoring our sophisticated temperature regulators and treating our fermentation chambers like cool, dark German caves.
Able to turn ale around in as little as two weeks using a ramped fermentation schedule, and fully aware that my theory could be wrong, I figured I’d apply the same logic when brewing my next lager — start cool and gently raise the temperature to encourage a quicker ferment, then cold crash to just below freezing for a few days, keg, and force carbonate. Lo and behold, this quick lager method worked, the beers came out just as good as those I’d made in the past, but they were ready in only three weeks. I was sold and proceeded to share the method with others, eventually learning that other homebrewers had been using similar techniques with the same success.
Of course, many homebrewers questioned this approach, some more adamantly than others, convinced that a side-by-side comparison of lager beers produced using the traditional and quick methods would be the only good way to know if the differed or not. I agreed and finally decided to put it to the test — with an experiment!
PURPOSE
To evaluate the differences between two lager beers of the same recipe fermented using either traditional or quick methods.
METHODS
Since quick lager advocates claim their method produces beer equal in quality to those fermented traditionally, I and the Brülosophy team who worked on this experiment with me thought it best to compare beers that were ready in their typical time frames. What this meant was the quick batch wouldn’t even be brewed until the traditional batch was done with primary fermentation and had entered the lagering phase. In an attempt to keep things as organized as possible, since both brew days were identical, I’ll present them together and emphasize points of divergence.
For this experiment, I figured a very simple recipe would make any differences more obvious to tasters. See the recipe to the right on this page. I was concerned about potential differences in pitching rates propping liquid yeast in starters, so after consulting with the crew, I opted to pitch two packs of Mangrove Jack’s M76 Bavarian Lager yeast, which has a recommended fermentation temperature range of 45–57 °F (8–14 °C).
On the evening prior to the first brew day, I measured out the grains for both batches, placing the unmilled portion for the quick lager batch in a sealed bucket to await a future brew day before milling the other half. Note that the quick lager grains were also milled the night prior to that brew day exactly five weeks later.
Since I’d be using the batch sparge method for these 10-gallon (38-L) batches, I collected precise amounts of mash and sparge water in separate kettles then adjusted them with the same amount of minerals and acid.
In order to ensure similar mash temperatures, it was important that I accurately measure the grain temperature to determine the proper temperature of the strike water, which BeerSmith made a piece of cake!
After mashing in, I allowed each to rest for precisely 60 minutes, stirring only once at the 30 minute mark.
I pulled a small sample from each mash at 10 minutes in to check the pH and was pleased to discover both hit my 5.3 target.
After the hour-long mash rests were complete, I batch sparged to collect the same volume of sweet wort, which was quickly brought to a rolling boil.
During the 1-hour boils, I added the same amount of hops at the same times, then proceeded to quickly chill each wort.
Thankfully, my groundwater temperature was the same on both brew days, allowing me to chill each to the same temperature (79 °F/26 °C) in a similar amount of time (10 minutes). Post-boil refractometer readings confirmed both batches were starting at the same OG.
Both carboys of wort were left for 10 hours in their own chamber set to 50 °F (10 °C), my target fermentation temperature, before receiving two rehydrated packs of Mangrove Jack’s M76 Bavarian Lager yeast. And this is where the fun began . . .
In order to eliminate any chance of temperature compromising the data, the team decided it’d be best to let the traditional batch ferment at 50 °F (10 °C) the entire time, going against the popular practice of gently raising the temperature toward the end of fermentation for a diacetyl rest. While activity was noticed within just 12 hours of pitching the yeast, the consistently cool environment made for a rather long fermentation period with a hydrometer reading 1 week post-pitch showing the beer had dropped a mere 0.011 SG points.
A cap of frothy kräusen hung around for weeks as the yeast slowly turned sugar into alcohol and CO2.
It took 24 days before the kräusen on the traditional beer finally dropped and airlock activity ceased. An initial hydrometer measurement showed that the beer had indeed dropped to the predicted FG, and with a second measurement 3 days later showing no change, I began gradually reducing the temperature of the chamber to 32 °F/0 °C.
It wasn’t until the traditional batch had been lagering for 1 week that I brewed the quick lager batch, exactly 5 weeks later. Again, in an attempt to reduce extraneous variables, we decided it’d be prudent to package the beers at the same time, meaning the traditional batch would be left to lager in primary while the quick batch was fermenting.
Fermentation took off equally as fast in the quick batch as evidenced by kräusen development within 18 hours. However, in contrast to the traditional batch, I began raising the temperature in the chamber after 5 days, eventually reaching 68 °F/20 °C just one week after being brewed.
As I’ve experienced many times before, all signs pointed to fermentation being finished just 12 days after the beer was brewed, with a hydrometer measurement verifying the predicted FG had been reached. I let the beer sit at the warmer temperature for three more days before taking a second hydrometer measurement that showed the FG hadn’t changed, and it just so happened to be the same as the traditional batch.
While I used to decrease the temperature of the beer gradually out of fear of stressing the yeast and causing off-flavors, after hearing positive stories from other brewers I started using an even quicker method of immediately setting my controller to 32 °F/0 °C , which is what I did this time. I kegged both beers the following weekend, eight weeks after the traditional batch was brewed and three weeks after the quick batch was brewed.
The filled kegs were placed in my keezer and put under 40 PSI for 24 hours before I reduced the gas to serving pressure. By the following weekend, with the beers carbonated and ready for serving, I noticed small difference in clarity between the lagers (see photos below).
RESULTS
Data for this experiment was collected on two occasions separated by seven days, the first occurring in my garage and the second at a monthly Tulare County Homebrewers Organization for Perfect Suds (TCHOPS) meeting. A total of 31 people of varying levels of experience participated in this experiment. Each participant was blindly served two samples of the traditional lager and one sample of the quick lager then instructed to identify the one that was different. In order to achieve statistical significance given the sample size, 16 participants (P<0.05) would have had to correctly identify the quick lager sample as being unique. In the end, 17 tasters (p=0.01) made the accurate selection, indicating tasters were reliably able to distinguish a beer made using the quick lager method from one made with a more traditional fermentation schedule.
The tasters who were correct on the triangle test were subsequently asked to complete a brief evaluation comparing only the different beers while still blind to the variable being investigated. The traditionally fermented lager was preferred by 11 of the 17 tasters with another four preferring the quick lager batch and two saying they noticed a difference but had no preference. In conversations following completion with the experiment, the most common comments had to do with how similar the beers were in general. Interestingly, one taster, still blind to both the variable and the style of beer, remarked that the quick method beer had a subtle sulfur note it that “makes it taste more like a Pilsner,” while another taster noted the traditional batch was tasting “a little more sweet, less crisp” than the quick batch.
My Impressions: Upon returning home from the aforementioned meeting, I put myself through six semi-blind triangles and consistently, easily, identified the unique sample. To my palate, both beers had a noticeable white grape-like flavor that, based off of information from others, seems to be something people are experiencing with Gambrinus Pilsner malt. I’m not particularly a fan of this character, which was more strongly expressed in the traditional beer, thus my preference for the beer made with the quick lager method, in which I detected what I thought to be a very light sulfur component that made the beer more pleasant.
DISCUSSION
Even before I committed to doing this experiment, whether or not quick lager methods produced qualitatively similar beers as those fermented with more traditional techniques wasn’t really my concern. Rather, I was more interested in my ability to make a beer I thought was delicious and had what I perceived as “lager character” in a shorter amount of time. While I completely understand and appreciate folks who wish to pay respect to those who came before us by sticking as rigorously as possible to traditional methods, it’s true my anecdotal experience using these heretically hastened techniques has been quite validating, leaving me almost convinced that extended fermentation and cold conditioning aren’t necessarily the key to achieving a divine lager beer.
The fact tasters were reliably able to tell the traditionally fermented lager apart from the one made using quicker methods five weeks later certainly supports the notion that either method has a unique impact on beer. And with a majority of tasters who got the triangle test correct noting a preference for the traditionally fermented beer, perhaps there is something to be said about taking a more patient approach when making lagers.
As for me, I’ve absolutely no plans to integrate extended fermentation and lagering into my brewing, primarily because I’ve always been happy with quicker methods, but also because I actually preferred the quick lager batch. This experiment made me even more curious about the variables involved in the brewing of lager beers and will certainly serve to motivate more experimentation in the future!
Clarity difference between a traditionally-fermented lager and a fast lager.
photo by Marshall Schott
Lager for the Lazy
(5 gallons/19 L, all-grain)
OG = 1.053 FG = 1.006
IBU = 25 SRM = 3 ABV = 6.2%
Ingredients
11.5 lbs. (3.7 kg) Gambrinus Pilsner malt
6.75 AAU Mt. Hood hops (first wort hop) (0.88 oz./25 g at 5% alpha acids)
2.25 AAU Mt. Hood hops (20 min.)
(0.7 oz./20 g at 5% alpha acids)
Mangrove Jack’s M76 (Bavarian Lager) yeast
3⁄4 cup corn sugar (if priming)
Step by Step
This is a single infusion mash. Mix the crushed malt with 4 gallons (15.2 L) of water to stabilize the mash at 151 °F (66 °C) and hold for 60 minutes. Batch sparge with enough water to collect 6.5 gallons (25 L) in the kettle, adding the first wort hops during the first run-off. Conduct a 60-minute boil. Add the second hop addition with 20 minutes remaining in the boil. At the end of the boil, you should have 5.5 gallons (21 L) in your kettle. Cool the wort to 50 °F (10 °C) for fermenting, aerate well and pitch your yeast. Over the course of the next 7 days, slowly ramp the fermentation temperature to reach 68 °F (20 °C). After two weeks, the fermentation should be complete. Bottle or keg as usual.
