Author: Malcolm Frazer

As a brewer who enters competitions a decent amount, keeping my beer away from oxygen is important to me, particularly when it comes to packaging it in bottles from my kegs. My fears that oxygen in the bottle prior to filling would negatively impact my beer was born out of years of research that left me concerned if the utmost care wasn’t taken to keep oxygen to a minimum, I’d end up wasting beer, an entry, and money. In my mind, oxidation could result in a great tasting beer bound for the medal circle ending up in that pitiful pile of bottles lingering around at the end of a competition, slated to be consumed by the often unfortunate volunteers.

And I’m not alone! Perhaps the most popular solution for bottling beer from kegs, the BeerGun by Blichmann Engineering is lauded by many for it’s ability to flush bottles with CO2 prior to filling, reducing both the risk of oxidation and the worries of many a competitive brewer. Then again, a Google search for “bottling from keg” produces a list of DIY solutions that are missing this component with users swearing it works just fine and often reporting positive competition results. As a believer in the havoc oxygen can wreak when introduced at packaging, I looked forward to putting it to the test in this xBmt!

| PURPOSE |

To evaluate the differences between a beer bottled from a keg using a method to reduce oxygen uptake and the same beer bottled from a keg with no effort to mitigate oxygen.

| METHODS |

In hopes of ensuring any impact caused by the variable would be easily noticed by tasters, I decided to brew a delicately flavored Cream Ale.

Cream Sha Boogie Bop

Recipe Details Batch Size Boil Time IBU SRM Est. OG Est. FG ABV 5.5 gal 60 min 20.7 IBUs 3.2 SRM 1.050 1.010 5.3 % Actuals 1.05 1.01 5.2 % Fermentables Name Amount % Pale Malt (2 Row) US 4 lbs 39.75 Pilsner (2 Row) Ger 3.25 lbs 32.3 Corn, Flaked 1.375 lbs 13.66 Acid Malt 12 oz 7.45 Cane (Beet) Sugar 11 oz 6.83 Hops Name Amount Time Use Form Alpha % Sterling 16 g 70 min Boil Pellet 8 Liberty 18 g 5 min Boil Pellet 5 Yeast Name Lab Attenuation Temperature German Bock Lager (WLP833) White Labs 73% 48°F - 55°F Notes Water Profile: Yellow Balanced in Bru’n Water Spreadsheet

A couple days before brewing, I made a starter of Omega Yeast Labs German Lager I from some slurry given to me by my friends at Helicon Brewing Company.

When brew day arrived, I weighed out and milled the grain while my strike water was heating up.

With the strike water ready, I mashed in to hit my target temperature then took a small sample of wort to about 15 minutes into the mash that confirmed I’d nailed the proper pH.

Once the 60 minute mash rest was complete, I collected the first runnings and performed a batch sparge to reach my preboil volume.

The wort was then boiled with hops added at the times laid out in the recipe.

At the conclusion of the boil, I quickly chilled the wort to my desired fermentation temperature before racking it to a sanitized fermentor.

A hydrometer reading showed I hit my target OG spot on.

I pitched the yeast and held the beer at 62°F/17°C 3 days, which is when I noticed slowing activity, so I gently increased the fermentation temperature to 68°F/20°C over the next few days.

With activity absent a few days later, I took a hydrometer measurement confirming my target FG had be reached. I reduced the temperature of the beer for a cold crash, fined with gelatin, then racked to a keg. The beer was briefly burst carbonated in my keezer before being set to serving pressure and left alone for a week of cold conditioning. Once I determined the beer to be adequately clear and carbonated, it was time came to introduce the variable.

Utilizing the popular Blichmann BeerGun, one set of bottles received a 45 second dose of CO2 to purge them of oxygen before being filled with beer and capped.

For the second set of bottles, I used the very simple picnic tap method without any attempt to reduce oxygen. While I know of brewers who have done well in competitions with beer bottled this way, the sloppiness of this approach made me cringe, as I didn’t even use a length of tubing to minimize splashing like it seems most people do.

Both sets of bottles were then marked and stored in my warm laundry room to somewhat simulate the conditions a beer might undergo when sent to a competition.

Having friends in the beer industry definitely has its perks, especially for a nerdy science guy like me. As a fun side xBmt, I ran some samples from both conditions to Roundabout Brewery immediately after bottling where co-owner Steve Sloan and his wife, Dyana, graciously helped me measure actual oxygen levels using their orbisphere.

It is suggested to take these measurements immediately after packaging in order to get an accurate oxygen level at that time, otherwise the amount of oxygen introduced when bottling is essentially “consumed by the beer.” Even the short drive between bottling and measurement had me a little concerned, but I figured something would be better than nothing. Over several trials, the beer bottled with the BeerGun averaged 26.5 ppb and 43 ppb of oxygen for non-shaken and shaken samples, respectively. As predicted, the beer bottled using the picnic tap averaged 250 ppb and 700 ppb of oxygen for the non-shaken and shaken samples, respectively. No question, these methods resulted in drastically different oxygen levels present in the packaged beer.

Purely to satiate my own curiosity, I also tested oxygen levels in beers bottled using a picnic tap attached to a length of tubing with a stopper to create back-pressure, similar to the Brü Bottler. The non-shaken sample clocked in at 45 ppb of oxygen while the shaken beer contained 117 ppb, still more than the beers bottles using the BeerGun, but quite a bit lower than those bottled without the tubing. This seems to support the notion that bottom filling may actually push oxygen out of bottles.

After 3 weeks in my laundry room, I moved all of the bottled beers to cold storage and let them hangout for a few days. Before collecting data, I opened bottles from both batches to see how they held up. Both were clear, carbonated, and identical in color, which went against my expectation since oxidation is said to have a darkening effect on beer.

| RESULTS |

A total of 41 people with varying levels of experience participated in this xBmt while hanging at the Grist House. Each participant was served 1 sample of the beer bottled using the BeerGun and 2 samples of the beer bottled using the picnic tap then asked to identify the sample that was unique. Given the sample size, 19 tasters (p<0.05) would have had to correctly identify the beer as being different in order to reach statistical significance. In the end, only 15 participants (p=0.38) accurately identified the unique sample, indicating in inability to reliably distinguish a beer bottled from a keg using methods to reduce oxygen from the same beer bottled with no effort taken to reduce oxygen.

Arguably meaningless since the xBmt failed to achieve statistical significance, I figured I’d share the preference data to satisfy curious minds. Still blind to the variable in question, the 15 people who accurately selected the unique sample in the triangle test were further instructed to compare only the two different beers then asked about their preference. In all, 8 tasters reported preferring the beer bottled with the BeerGun, 3 said they liked the beer bottled with a picnic tap more, 2 had no preference despite noting a difference, and 2 reported noticing no difference between the beers.

My Impressions: I attempted 3 semi-blind triangle tests a few days after bottling out of which I selected the odd-beer-out twice, meaning the difference was not stark enough for me to nail it every time. To my palate, the beer bottled with the picnic tap seemed to take on a slight vinous note that I believe assisted my choice, and the fact my wife picked the unique sample the one time she tried was validating. Then, I tried again 3 weeks later in preparation for data collection and was unable to reliably differentiate the beers, to the point ended up guessing and was wrong 3 out of 4 times. The fresh corny sweetness I perceived when fresh had changed into a cooked honey character with the same vinous note I detected a few weeks earlier, only this time it was present in both beers.

| DISCUSSION |

Oxidation is a known phenomenon that is objectively measurable, there’s no arguing this fact. However, the extent to which its impact on beer is perceivable is, well…

Screw it, I’m just gonna come out and say it– I am truly perplexed by these results, they go against everything I know to be true about oxygen and packaging. And I’m not just relying on the data from the blind participants here, I couldn’t tell the damn beers apart myself, which has really got my head spinning! We know oxygen during packaging negatively impacts beer, it’s why commercial breweries spend oodles of money on equipment to keep it to a minimum. We also know, based on objective measurements with an orbisphere, the beer bottled using the BeerGun contained notably less oxygen than the beer bottled straight from a picnic tap. So why the hell didn’t they taste different enough for people to tell them apart?!

I’m so baffled, I’ve found myself inventing potential reasons for these results, for example, perhaps the period of warm storage led to a convergence of oxidation such that both beers were affected to the point of being indistinguishable. Then again, if this is true, what about the efforts made by many to reduce oxygen when bottling beers that then get placed in warm boxes and bumped around for days on their way to a competition? It’s also possible certain people aren’t as sensitive to oxidation character as others, which might help explain the data showing a rather strong general preference for the low oxygen beer among those who were correct on the triangle test. Or maybe the beer had some other fault that caused both to be equally oxidized regardless of packaging method. I really don’t know, but combined with findings from the recent oxidized kegging xBmt, I’ve found myself with far more questions than answers.

I absolutely plan to continue exploring oxidation during packaging, admittedly in hopes of confirming my own biases, though open to having them chipped away at as well. Has this xBmt inspired me start filling bottles from kegs with a teaspoon and funnel because it obviously doesn’t matter? Nope! I recently sent some beers to the National Homebrew Competition that were packaged with every effort made to eliminate oxygen pickup, and that’s what I’ll continue to do if only for the sake of insurance.

If you have any thoughts on this xBmt, please share them in the comments section below!

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