This xBmt was completed by a member of The Brü Club as a part of The Brü Club xBmt Series in collaboration with Brülosophy. While members who choose to participate in this series generally take inspiration from Brülosophy, the bulk of design, writing, and editing is handled by members unless otherwise specified. Articles featured on Brulosophy.com are selected by The Brü Club leadership prior to being submitted for publication. Visit The Brü Club website for more information on this series.

Authors: Chris Cook & Marshall Schott

Ask any brewer who what the most important aspect of producing consistently high quality beer is, and one of the most common responses is guaranteed to be pitching an adequate amount of yeast. While once can achieve the proper viability by simply pitching multiple pouches of yeast, a more cost-effective method involves propagation of yeast in a starter, which these days appears to have become the norm.

The purported benefits of pitching highly viable yeast are many– quicker starts, faster finishes, and reduced risk of undesirable off-flavors. Since the only real downside is that making a starter takes about 20 minutes, it makes sense that so many people have adopted the practice, plus it can cost quite a bit less than purchasing multiple pitches of yeast.

However, there are those who question the necessity of making yeast starters, whether due to positive anecdotal experiences with direct pitching straight from the pouch or previous exBEERiments that failed to support the practice as qualitatively beneficial. It was this conundrum that inspired The Brü Club member, Chris Cook, to retest this variable using a yeast strain some believe is more sensitive to pitch rate!

| PURPOSE |

To evaluate the differences between a beer pitched with yeast direct from the package and the same beer where the yeast was propagated in a starter prior to being pitched.

| METHODS |

After receiving several requests from friends to brew a beer that tastes like Yuengling, I eventually caved, searched the internet for a clone of this classic American lager, and went with the highest rated recipe I could find. The beer ended up being a dark-copper banana bomb, which is odd seeing as it was fermented with a popular Chico yeast strain. Regardless, the keg was quickly kicked and requests for more came pouring in. I’ve made it a few times since and was curious to see how it’d turn out using Imperial Yeast A04 Barbarian.

Banana Hammock

Recipe Details Batch Size Boil Time IBU SRM Est. OG Est. FG ABV 5.5 gal 60 min 30.0 IBUs 11.4 SRM 1.054 1.010 5.8 % Actuals 1.054 1.016 5.0 % Fermentables Name Amount % Pale Malt (2 Row) US 8.625 lbs 70.41 Caravienne Malt 2 lbs 16.33 Munich Malt, Germany (Avangard) 1.125 lbs 9.18 Caramel Malt - 120L (Briess) 8 oz 4.08 Hops Name Amount Time Use Form Alpha % Centennial 22 g 60 min Boil Pellet 10.6 Cluster 22 g 5 min Boil Pellet 7.8 Yeast Name Lab Attenuation Temperature Barbarian (A04) Imperial Yeast 74% 62°F - 70°F Download Download this recipe's BeerXML file

Due to yeast age and batch size, BeerSmith predicted the pouch of Barbarian yeast contained 111 billion viable cells, which was about half of the recommended pitch rate of 223.3 billion cells. Per the yeast starter calculator, a 2 liter starter would result in 223.2 billion cells, just shy of ideal, which would have to do seeing as Chris’ flask was at its limit. When brew day came around, Chris started off by weighing out and milling the grain.

Following a 90 minute single-infusion mash at 147°F/64°C, a fly sparge was performed until the proper pre-boil volume was collected.

The full volume of wort was then boiled for 60 minutes with kettle hops were added at the times listed in the recipe.

Once the boil was complete, Chris took a refractometer reading showing the wort was at 1.054 OG. Seeing as his brewing area had yet to be plumbed, he was unable to use his chiller and resorted to a fairly unconventional method– after allowing the wort to chill in the kettle for a bit, he split it evenly between identical fermentation buckets and placed them outside in the frigid cold to finish chilling. Later that evening, he moved the worts to his basement and let the temperature stabilize overnight. The next day, he returned to pitch the yeast, one receiving the contents of a single pouch while the other was hit with a starter.

The beers were left to ferment in Chris’ cool basement that averaged an ambient temperature of about 63°F/17°C. After 2 weeks, signs of activity had slowed down so he took hydrometer measurements showing the direct pitch beer had a slightly higher SG than the beer pitched with a starter.

Since the beers were fermented in opaque buckets, Chris was unable to observe actual fermentation activity, but the difference in SG suggested the yeast starter did hasten the process. He also noticed a difference in the kräusen rings between the buckets.

The beers sat for another week before Chris took a second set of hydrometer measurements showing both had settled at the same 1.014 FG. At this point, the beers were kegged, carbonated, and allowed to condition for a few days before they were served to participants.

| RESULTS |

A total of 21 people of varying levels of experience participated in this xBmt. Each participant was served 1 sample of the direct pitch beer and 2 samples of the beer made with a yeast starter in opaque cups marked either A, B, or C then asked to identify the unique sample. A total of 12 tasters (p<0.05) would have had to accurately identify the unique sample in order to reach statistical significance, though only 8 did (p=0.40), indicating participants in this xBmt were unable to reliably distinguish an Amber Ale fermented with yeast pitched directly from the same beer pitched with an adequately sized yeast starter.

Chris’ Impressions: Initially, Chris reported perceiving the direct pitch and yeast starter beers as being largely similar, though he felt the latter was slightly less astringent and a bit more sweet than the former. Despite their similarities, Chris said he was able to identify the odd-beer-out in the 3 triangle tests he attempted, though acknowledged he had no preference and likely wouldn’t be able to tell the difference if someone swapped pints.

| DISCUSSION |

There’s little doubt yeast viability is an important factor in the production of quality beer, with many crediting the adoption of yeast starters as a change that led to the biggest improvement in their finished product. Underpitching is known to increase the risk of off-flavor development, which can be avoided by pitching an adequate amount of cells.

Interestingly, tasters in this xBmt could not reliably identify a beer fermented with a single pouch of yeast from one pitched with a starter, suggesting underpitching had little impact on beer quality. These findings corroborate those from quite a few past xBmts on pitch rate, leaving one to question the veracity of claims that underpitching is universally detrimental to beer, though there is some evidence that overpitching has a perceptible impact.

When it comes to brewing consistently great beer, there’s nothing wrong at all with employing methods to reduce the risk of problems. While these and past results may not glaringly demonstrate the ills of underpitching, there’s little doubt that pitching yeast of high viability increases the chances of a positive outcome, and vice versa. It’d be a misconception to interpret these results as a recommendation to ignore pitch rates, though in a situation where one has a relatively fresh pack of yeast, pitching directly may not be something to fret too much over.

Chris Cook is a Certified Beer Server living in Louisville, KY. Chris is an active member of The Brü Club where he enjoys engaging with other science-minder brewers. In addition to brewing, Chris loves being active with his girlfriend, daughter, and crazy-dog Nitro. When he’s not brewing something up in his homebrewery, Chris can be found doing triathlons, mud runs, obstacle races, or writing code. Follow Chris on UnTappd. Would you like to have your experiment featured on Brulosophy.com? Join The Brü Club today! The Brü Club is a growing community of curious homebrewers who regularly engage each other on topics important to us all. Membership is free and comes with all sorts of cool opportunities. Learn more at TheBruClub.com! If you have any thoughts about this xBmt, please do not hesitate to share in the comments section below!

Support Brülosophy In Style!

All designs are available in various colors and sizes on Amazon!

Follow Brülosophy on:

If you enjoy this stuff and feel compelled to support Brulosophy.com, please check out the Support page for details on how you can very easily do so. Thanks!

Advertisements

Share this: Facebook

Twitter

Pinterest

Tumblr

Email



Like this: Like Loading...