Brewnundrum

Aeration Revisited

Four Methods Battle Head-2-Head

Oxygenation Revisited – Why

• Use of Hydrogen Peroxide was contested by club members with solid chemistry background.
• I’ve used Hydrogen Peroxide to make good beers, but too many had “unstable” flavor profiles.
• Summary article in Zymurgy on the initial experiment by Ron Cooper was against its use!
• Original article did not include blind tasting.
• Received in depth information on the use of olive oil at NBB by Grady Hull.

The Initial Experiment

• In original experiment included many beers that were entered in the 2004 Mayfaire homebrew contest
• Only those that used air pumps or pure O2 did well
• Those using Hydrogen Peroxide scored very poorly with comments about lack of malt or hop flavor and light body – called “two-dimensional” and “insipid”
• I was one of the judges at that contest when Ron first told me of his experimenting with Hydrogen Peroxide but I did not know about his final conclusions.

The New Experiment

• Make an Belgian-Style Dubbel with Chimay yeast
• Split the wort into 4 fermenters and then Oxygenate / Aerate via 4 different methods
• Pitch the same amount of yeast in each and ferment all 4 at the same temperature
• Ferment at high temperatures to develop esters and distinct yeast driven flavors in the beer
• Blind tasting – gather feedback on each before revealing which method was used on each sample.

 

·        Photos from the brew day - Beginnings

       

• Photos from the brew day                                                     The Key Players (aquarium pump, pure O2 and Peroxide)

 

 

•  Photos from the brew day – Divide & Conquer

 

• Photos from the brew day                                            Aeration in Action (aquarium Pump, shaking, pure O2)

 

 

 

 

 

• Photos from the brew day                                                    The 4 Musketeers

 

 

 

• Photos from the Fermentation                                            Day 1 @ morning (Already Cranking Good!)

  

• Photos from the Fermentation                                            Day 2 @ morning (at high kreusen)

 

 

• Photos from the Fermentation                                            Day 2 @ evening (already finishing on one batch)

 

• Photos from the Fermentation                                            Day 3 @ morning (finished on all but on one batch)

 

• Findings

• An Update on the use of Olive Oil by New Belgium Brewing Co.

From: Grady Hull

Sent: Tuesday, November 29, 2011 9:02 AM

 

Subject: Use of Olive oil instead of aerating wort

 

 

      Hi Shawn,

          I tested using olive oil as a yeast nutrient to replace wort aeration with the hope of improving the shelf-life of our beers.  The idea is that instead of giving the wort oxygen so it can remove a hydrogen from a saturated fatty acid, we give the yeast a monounsaturated fatty acid (oleic acid), with the hope that the reduced exposure to oxygen will result in better shelf-life.

              Unfortunately the gains we saw in shelf-life were minimal and did not justify putting in an elaborate olive oil dosing system.  I personally wouldn’t recommend it for home brewing since slight differences in shelf-life are less important.  The best thing we have found for keeping beer fresh in a bottle is still just to leave some live yeast in there.

              We use filtered air most of the time unless we are working with a difficult yeast strain, then we use O₂.

         Hope this helps,

         Grady

 

At the end of the experiment bottles of each version of the beer was presented at a blind tasting at Addison Homebrew Provisions. Ron Cooper was kind enough to drive over 40 miles to come to the meeting. The color, aroma and flavors that the 30-odd homebrewers could detect were noted during the blind tasting. At the end, a vote was taken and we found that while using an aquarium pump gave the flavors I was looking for, shaking the carboy was the most popular and gave the most malty flavors. Using pure O2 was good, but not nearly as popular as the others and using hydrogen peroxide was a complete disaster. Ron Cooper believes in using no additional oxygenation (other than spashing into the fermenter) in order to achieve the best flavored beer.

Updated 1-18-13: Here are the flavors and aromas that were thrown out during the blind tasting at AHP.

 

Fermenter #1 – Aquarium Pump

Sweet ,Fruity ,Citrus ,Peppery ,Bready chewiness ,“Belgian” Esters . Slightly lighter color than #2 or #3

Fermenter #2 – Peroxide

Dry ,Bitter ,Carmel sweetness ,Thin body ,Flat finish ,Few Esters
 

Fermenter #3 – Pure O2

Creamy ,Malt sweetness ,Less Fruity than #1 ,Hot – Alcoholic ,Phenolic from pepper & alc. ,Slight sourness at finish ,Some caramel flavors, but less than #2

Fermenter #4 – Shaking

Viscous body ,Slightly darker color than 2 or 3 ,Lots of sweet maltiness ,Slight pepper ,Gentle hops ,Mellow, English style esters – not the same as #1


Since the presentation, I've purchased an aquarium pump with dual outlets, two filter and two stones and my beer has never tasted better. Sometimes the simpler, more tried and trued ways of doing things turns out the best. Whe I revisit this topic I use a dissolved oxygen meter to dial in exactly how much O2 yields the best ester profile for some of my beers!

Thanks goes out to Nico for the extra carboys, Daniel for the use of his aquarium pump, Ron Cooper for taking the time to come to the meeting and his constant inspiration and AHP brew club member Unfrgvn82 for challenging me to prove my assumptions...good friends are like that!