Writeup: BrewTan - Or Do Oxygen Scavenging Chemicals Change the Beer Character - Updated

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The Magic Dust

Could this be all you need to make stable, characterful beers?

Heads Up: We've updated the results with an additional IGOR panel. It sorta changes things.


Executive Summary

After years of telling people "Oh HSA doesn't matter really", the new hot concern amongst brewers has become any oxygen involved in the brewing process. You'll see references to some fairly complicated brewing methods called LODO (Low Dissolved Oxygen). Supporters of the technique claim some great benefits to the process, but the means to get there is pretty arduous.

But is there a better way through chemistry? Award winning brewer Joe Formanek works for the Japanese firm Anjinomoto that produces, amongst many things, a series of tannic acid products for brewing. The long molecule when dissolved in both the mash and the boil is supposed to improve clarity, yield and reduce oxygen's impact on flavor degradation. The product is finding great traction globally as a brewery additive, but isn't yet easily available to homebrewers here in the states. (Joe's working on that and we'll let you know when you can buy.)

Joe sent our IGORs samples of BrewTan B to try in their brews. We had 8 IGORs return results so thanks to Ryan Casey, Dan Chisholm, Michael Drzewianowski, Tim Hayes, Jason Mundy, Eric Pierce, Sean Shanahan and Eric Stonfer for partaking and doing the diligent work! Of the 8 panels, 6 of them return results consistent with random guessing (~33% correct choice). 

We talked through the results with Joe on Episode 38 - Gluten Free Tanning. Together one of the important conclusions on this experiment is we need to revisit the results on two fronts - age (to explore oxidation impact) and visual testing, since clarity.  Also, it turns out that Anjinomoto has revised their dosing instructions, so...

Another interesting result - despite the tasting panels running to the random, the reporting IGORs feel like there are noticable differences in the brewng process and want to keep using the product. (Denny feels this way as well!)

Mike's results came in after the bell and have affected things - so let's look and see.

The Experiment

For this one, we wanted to turn the IGORs loose and let them have some fun. We simply asked - go forth and brew two batches of the same recipe - one with BrewTan and one without. Take plenty of pictures and notes along the way and then do a blind triangle test to see if people can determine a difference.

The instructions as given to us originally and used by the IGORs (to various levels of tightness) are documented in the experiment design, but here are Anjinomoto's updated guidelines.

BrewTan Usage Instructions (Updated April 2017)

Mash/Sparge: Add 1/4 tsp per 5 gallons of mash and sparge water to the water and dissolve.

Boil: Take a small portion of hot water, stir 1/2 tsp (per 5 gallons) to dissolve. When clear, add the BrewTan to the boil before adding any whirlfloc/irish moss/kettle break.

 For the full detals of the experiment, read the experment design!

The Brew Day

As above, we gave the IGORs a free brew day. Why? Well, for this experiment - the recipe, in theory, doesn't matter and while it sure it would be easier to detect differences if everyone brewed kegs upon kegs of Magnum Blonde that's just not as much fun. Hell, I love the beer and I don't want to brew kegs upon kegs of it! So let's see what our IGORs made

Ryan Casey RyNie Original Lager
Dan Chisholm American Pale Ale
Michael Drzewianowski Citra Wheat Pale Ale
Tim Hayes International Amber Lager
Jason Mundy Munich Dunkel
Eric Pierce Hoppy Pilsner
Sean Shanahan Cascadian Dark Ale (Black IPA to you non-NWers)
Eric Stonfer German Pils

What I thought was really interesting - out of our 8 test beers, 5 were lagers - way to break the homebrew legacy, gang!

A few things to note out of the days activities as we show you pictures. The BrewTan additive seemed to temporarily darken the water color for some of the mashes. Also almost all of our IGORs noted a visual impact to the wort and finished beer as you can see below.

The Pictures

Ryan Casey - Rynie Original Lager

BrewTan Sample on Left, Control on Right. Color look different to you?

Dan Chisholm - American Pale Ale

Two different batches, two different OG samples after the boil (First with BrewTan, Second - Control)

Mike Drzewianoski - Citra Wheat Pale Ale

The two beers at their original serving time. BrewTan batch is on the right.

The same beers, same glasses, four months later. BrewTan Batch on the right - again. Read on for the impact statement.

Jason Mundy - Munich Dunkel

Jason's Brew Board

This has nothing to do with the experiment, but I have to admit, I'm a little jealous of the brew board.

Chilled Brewtan OG SampleThe Chilled OG Control Sample

Chilled OG Samples (Left: BrewTan, Right: Control)

Brew Tan Viewed Through a HoseControl Viewed Through a Hose

Final Beers Viewed Through Hoses - Left: BrewTan, Right: Control

Eric Pierce - Hoppy Pils

Eric's Side By Side

Eric had a bit of a flub on his brew. Two batches, both with BrewTan - One with proper dosing. Look at that break on the right with full BrewTan.

Sean Shanahan - CDA

BrewTan B Post BoilControl Post Boil

Post Boil Samples - Left with BrewTan, Right - Control

Beer Lines - Brewtan on Right

Two Beer Lines Enter - On the Left - Control; On the Right - BrewTan

Pink Iosophor

Apropos of nothing but "huh" - The Iodophor solution went pink when added to the mash tun post BrewTan.

The Tastings

For this go around we had 74 total tasters spread out across 30 tastings. (nice set of panels!) As usual the tasting panelists were a mix of experience levels and beer knowledge. Beers were served blind and in proper triangle fashion. One IGOR ran his panel with clear cups because the beers appeared to be identical. All of the beers were served fresh.

Jason's Tasting

Preparing to Taste Some Beers!

The Results

So let's dig into the results from our testers and see what there is to be seen. As we noted in the executive summary - the results are a bit mixed with the addition of the new trial and 6 of the 8 tend to the area of random chance. (Also as noted, we're still trying to find a better way to aggregate the multiple trials and make it so we understand the technique and can explain it to you too). What's interesting to me is that despite 6 of the 8 trials coming in with no signficance indication, the aggregate firmly gets over the line. Yes, I believe this really means the aggregate does funny things, mathmatically speaking.

  Total Tasters Successful ID's %age Correct p-Value
Magic Threshold 74 32 43% 0.048
All Data 74 35 47% 0.009
Pre-Michael Results 59 24 41% 0.145

Tasting Panel Numeric Data

IGOR Panels Tasters Successful ID's %age p-Value
Ryan Casey 1 6 2 33% 0.649 (NOT significant)
Dan Chisholm 3 9 2 22% 0.857 (NOT significant)
Mchael Drzewianowski 13 15 11 73% 0.002 (significant)
Tim Hayes 1 6 2 33% 0.649 (NOT significant)
Jason Mundy 1 7 5 71% 0.045 (significant)
Eric Pierce 4 12 5 42% 0.368 (NOT significant)
Sean Shanahan 3 8 3 38% 0.532 (NOT significant)
Eric Stonfer 4 11 5 45% 0.289 (NOT significant)

Tasting Panels Qualitative Data

IGOR Beer Thoughts Experiment Thoughts
Ryan Casey

Crazy good beer. I found that the BrewTan beer was a bit "brighter" and had a little fresher flavor. I was able to tell the beers apart on 2 out of 3 "blind" triangle tests, but unfortunately my tasters didn't do as well.

I will NEVER EVER brew without BrewTan B again!!! I'm amazed at what this does to the flavor and color of my beer. Even with the Zymatic I can produce beers that are far clearer and lighter than I ever could. I even use it when I brew on my Pico!
Dan Chisholm
I bottled some from each batch to do future tastings in a month or so to see if Oxidation plays any roll or a change in results.
Not sure if I have a grasp on this yet. I think the future tasting will be interesting to see if the non-BrewTan batch will have Oxidation off flavors.
Michael Drzewianowski I had 15 people taste the two beers over a 2 weeks period.  These were mainly done as one-offs at a birthday party and during the holidays so there was not much “group” think going into the results.  Only 3 commented on preferring the non-brewtan beer better and mainly that was because the bitterness was more pronounced and it had a slightly lighter mouthfeel.  The others chose the Brewtan beer for its slightly softer hop profile, better aroma and more rounded mouthfeel.  I also chose the Brewtan beer and could easily pick it out of a triangle test based on aroma alone, it was that different.  
Tim Hayes The beers were poured in clear 5 oz cups. I used clear because the color was exactly the same. You could not pick out the different beer by visual inspection. 1 sample of the brewtan and 2 samples of the non-brewtan beer were poured. Sample 1 (non-brewtan) received 1 vote, sample 2 (brewtan) received 2 votes, and sample 3 (non-brewtan) received 3 votes. The tasters were not given any information about the beer experiment nor the style of beer. All they were told was that two of the three beers were the same and to pick out the unique beer. I was expecting a greater difference between the two beers going into the experiment. Even trying them side by side from the keg, I could not pick out much of a difference between the two beers. I would like to do brew again with the remaining BrewTan I have. I am going to try different styles to see if the style of beer benefits more from using BrewTan.
Jason Mundy Everyone seemed confident in this tasting. More so than those in the past. I liked the BrewTan-B in the beer. Will continue to use it for my german lagers if available. Not sure if it really helps with reducing oxygen in the beer.
Eric Pierce

Both batches had a bitter, kind of metallic mouth feel. Initial samples had an lingering astringent aftertaste. After about a month in the kegs, refrigerated the whole time, the aftertaste has dissipated. It's an ok beer but definitely not my best. A step backwards from my last pilsner.

I did the triangle test myself where someone scrambled cups (same color, numbered on the bottom) and I was able to discern the different one based on the non-BrewTanB beer having slightly less of the aftertaste.

The difference between the batches was not striking. Definitely something different happening with the cold break. 

The recipe I used was a deviation of my last pilsner where the intent of the changes was to amp up both malt and hop character. I clearly over did it in the hop department. One of the three hops I used was suspect with regard to age and oxidation so instead of avoiding it, I just counted them with lower alpha. Bad move. Even with my corrections, BeerSmith told me I was pushing it.

It is possible that the flaws in my recipe and process that led to extra bitterness, yeast stress, and too much hot break slurry masked some of the benefits that BrewTanB offered.

Sean Shanahan The BrewTan-B samples had a much thicker head when poured from the tap and a smoother overall taste between the malt and hop bitterness. It came across as a creamier ale with less noticeable tannin astringency. The non-BrewTan batch had a harsher hop bitterness bite with less head retention and a stronger, more noticeable astringency. Overall I was really impressed with the BrewTan-B in rounding out the flavor into a more blended ale as well as the huge difference in protein clumps from such a small addition. I'm curious if the irish moss is necessary at all. I still have some of the provided sample left and will use it in a future batch with out the irish moss to see what happens.
Eric Stonfer Crisp german pilsner, slight sulfur notes, pale straw color My brewing methodology already makes heavy use of LODO techniques, and already precludes the use of copper (which likely would reduce Fenton reactions). Next time I might run them through my PicoBrew instead just to see if I could see a difference there.

Subjective Responses

As we noted above, the different beers couldn't be successful differentated blindly. But what did the panelists think when asked for their comments? (Keep in mind - these are all different recipes so impacts might be different)


  • More Overall Rounded Flavor (APA, Citra Wheat)
  • More Blended and Less Harsh (CDA - Roast impact perhaps?)
  • Less Bitter, Better Hop Aroma (CDA, Citra Wheat and Pils)
  • Clearer looking
  • Better head (CDA)


  • Slightly thinner, less estery (Dunkel)

When asked about the beer, many of our IGORs felt they couldn't reliably tell the difference. Sean Shanahan actually went and redid his tasting panels though because the first time through he had 100% identification rates due to the BrewTan-B pouring with a stronger head. He discarded the results and ran more panels after first pouring the beer in to growlers and letting things settle. 

From a brewing point of view, there was an interesting piece of data from several of the IGORs who noted wort darkening in the mash in the BrewTan batches. But I think the gem of all the responses - which while not technically useful is really damn funny - comes from Jason Mundy who notes that he...

Tasted the BrewTan-B and wort slurry. Wow... was that puckering. There needs to be a BrewTan-B challenge on Youtube.


Well, the BrewTan didn't show quite the results we were expecting when tested against fresh beer when presented in a blind trial. There's further results that we need to see because there's a visual impact that many of the brewers saw and we need to explore aging impacts as that's one of the place BrewTan is supposed to really shine. Maybe for the future test we torture the IGORs and make them brew the same beer. (or not, we love you guys!)

But like we said earlier - it is interesting that despite the lack of significance in this trial, most of the IGORs saw value in using the additive. Denny swears by it too.  And keep in mind that we didn't test one of the things that Brewtan B is supposedly best at...extending the "shelf life" of your beer.  We hope to undertake that experiment, too.

This is certainly prompted by that second photo from Mike and his comments about his Citra Wheat 4 months later.

Brewtan B - 4 months later… huge clarity difference and more importantly a huge difference in aroma and taste. The Brewtan version still has a good amount of aroma and has a nice crisp taste where the non-brewtan version has zero aroma and a flat taste and also showing some signs of oxidation.

That sounds encouraging and we'll definitely be following up there.

So we know we got something wrong here - let us know in the comments below or email us at [email protected].

DrGMG's picture
Any more results of aged

Any more results of aged beers? where can I buy it? The only place I've seen it sells it for $7/ounce, plus shipping...