Testing for Diacetyl


A few weeks ago I got results back from the Alamo City Cerveza Fest.  I was looking forward to these results for a number of reasons, one being just because of all of the drama.  The other was a different set of opinions about Big Fat Phony, a beer that we infused with peaty Scotch.  And finally, I had sent in an IPA of mine that originally I wasn’t so sure of, but in the past couple of weeks before sending had really turned into something quite nice.

That I didn’t place with it wasn’t much of a surprise.  Instead, I take solace in collecting the feedback so I can focus on making better beers, more so than any desire to win a competition.  On my score sheet however was something I was pretty shocked to read.  A very noticable flaw, diacetyl.  That lovely aroma of movie theater butter popcorn.  Most folks can pick it up a mile away; and it’s detectable at very light levels, in the parts-per-billion.  And here on my score sheet, two judges pick it up.  One of them even says that it’s over-shadowing the rest of the beer.  Wow.

I was completely stunned and crushed.  I’ve been drinking this beer since it was kegged with not a hint in sight.  But that’s not always good enough.  In many cases the beer can have diacetyl precursors which once exposed to warm temperatures and oxygen can reform into diacetyl.   Strugging with this possiblility I wondered how I could find out without bottling and waiting two weeks.

It turns out that diacetyl levels are actually a really good indicators of fermentation progress.  In the fermentation process diacetyl levels increase during yeast growth phase.  Near the end of fermentation, gravity reduction has ceased, but the yeast are still working to finish up, and consume many of the by-products (such as diacetyl) that were produced earlier in fermentation.  If you can test and detect diacetyl levels (usually done via gas chromotography in a lab) then you can know for certain when the yeast are “done”.

As a homebrewer we don’t usually have access to $40,000 equipment, but we can perform a test that can help determine if diacetyl or pre-cursors are present.  I decided that I needed to use this to test if my IPA was harboring some skanky butter aroma.    The test itself is simple.


Pour two samples of the beer into glasses and cover (foil or plastic wrap).  Prepare a pot of water that one of the samples can sit in and heat up to 140F to 160F and hold for 10 to 20 minutes.  Then place the hot sample in a basin of ice water to chill it back down to the same temperature as the unheated sample.


After removing the cover of the two samples assess if either sample contains the dreaded butter aroma.  If the cold sample is affected, then trivially the hot sample will and the beer needs more time with the yeast.  If only the heated sample does, then the beer has diacetyl.

I never did detect anything in my beer… better luck next time I guess.

Sophie Amalie, a Belgian Blonde


Sophie Amalie of Brunswick-Lüneburg (24 March 1628 – 20 February 1685) was queen of Denmark

This Friday, I’ll be brewing up only my second Belgian recipe.  The first was really a sour attempt that’s still undergoing secondary fermentation.  Once it starts to develop some decent flavor I’ll be sure to post something about the experience.

I tend to have some pallet trouble with Belgian beers.  Mostly they’re too sweet for me at this point.  Every now and then I run across some great beers despite the general focus on lots of residual sweetness and low hopping rates.  I’ve even had a chance to taste the “greatest beer in the world“, Westvleteren 12.  So far over-rated that I don’t even know where to begin.


One of my best friends was able obtain some of this beer and I picked up what some say is the identical beer, St. Bernardus Abt 12.  We performed a side-by-side and while I picked up some subtle differences in carb and sweetness; it’s so close on flavor and miles away on price that everyone should just forget Westy 12 and pickup the more commonly distributed and equally good (if a strong, sweet, belgian ale is what you’re looking for) beer for far far less.

Now that you know I’m not a big fan, I do have to say there are some really great belgian beers out there.  My current favorite which was absolutely stunning to me, was  To Øl‘s Sans Frontiere.  A huge Belgian Pale or IPA beer.  It has all of the flavor characteristics of a typical Belgian beer, but it has an enormous hop nose and flavor that just brings so much more character and flavor to the beer.  And to top it off; it’s bottled with Brett yeast which gives the beer another dimension just not typically found in Belgian Pale Ales.

With this great beer in mind, I turned to another challenge on the homebrew.  Pro-AM brewing around Austin, Texas.  Flix Brewhouse, the first brewery/theatre combo around is holding a competition and the style focus is 18A, Belgian Blonde.

I’ve pulled together what I think would be a simple, but classic Belgian Blonde recipe, styled after one of the beers in Brew Like a Monk and described by Jolly Pumpkin’s Ron Jefferies.

I’m looking forward to brewing this beer to see if it has the same amazing character that Sans Frontiere does.  I’ll be looking at a new technique of naturally carbonating the beer in a keg with Brett yeast.

Here’s the recipe, which is much more easily shared now that I’ve found a BeerXML wordpress plugin.

Recipe Details

Batch Size Boil Time IBU SRM Est. OG Est. FG ABV
5.3 gal 90 min 27.7 IBUs 5.8 SRM 1.062 1.004 7.6 %
Actuals 1.046 1.01 4.7 %

Style Details

Name Cat. OG Range FG Range IBU SRM Carb ABV
Belgian Blond Ale 18 A 1.062 - 1.075 1.008 - 1.018 15 - 30 4 - 7 2.2 - 2.8 6 - 7.5 %


Name Amount %
Pilsner (2 Row) Bel 7.098 lbs 60
Wheat Malt, Ger 3.904 lbs 33
Chocolate Malt (Thomas Fawcett) 0.5 oz 0.26
Corn Sugar (Dextrose) 12.76 oz 6.74


Name Amount Time Use Form Alpha %
Styrian Goldings - FHBS - 20130401 1.27 oz 90 min Boil Pellet 3
Hallertauer Mittelfrueh 0.47 oz 60 min Boil Pellet 4.3
Crystal 0.17 oz 1 min Boil Pellet 3


Name Amount Time Use Type
Calcium Chloride 6.40 g 60 min Mash Water Agent
Gypsum (Calcium Sulfate) 3.40 g 60 min Mash Water Agent
Epsom Salt (MgSO4) 0.50 g 60 min Mash Water Agent


Name Lab Attenuation Temperature
Belgian Ale (WLP550) White Labs 82% 68°F - 78°F


Step Temperature Time
Saccharification 147°F 90 min
Mash Out 168°F 10 min

2013-04-12 – Initial pitch at 75F, temp lowered to about 68F.
2013-04-13 – Active and vigourus fermentation at 7AM
2013-04-14 – switched blowoff containers, bumped temp up to 70F
2013-04-15 – switched blowff containers again, bumped temp up to 72F
2013-04-23 – pulled first sample, S.G 1.008 @ 72F -> 1.010. Nice light color, a little cloudy, nice spice, a bit of sulfur in the nose. Recommendation is another one to two weeks in primary to help push FG down a few more points, and possible clean up sulfur nose. Thinking of a very light (.25 oz) dry-hop of crystal or willamette.
2013-05-05 – pulled a second sample, S.G 1.006 @ 73.4F -> 1.007. Color still very light, brilliant clarity as yeast have dropped out. Great Belgian aroma, sugar, sweet nose, lemon. Light on the spice. Sulfur all gone. Mouthfeel is thicker than expected… Looking really nice. Transferred to keg for natural carbonation to 2.4 Volumes.

Competition Drama


Today was a Good Beer Day

I’ve been working on entering beers in all of the Lone Star Circuit Brewing Competition this year.  I’ve already received results from the BlueBonnet Brewoff.  The next in the series is the Alamo City Cerveza Fest.  I initially had some trouble importing my recipes via beerXML into their competition software (which btw is Open Source, and widely used at all of the AHA competitions).  So it was odd that this worked fine for the BlueBonnet Brewoff but I was having trouble with ACCF.

A short email to their contact and we settled that it wasn’t going to work but the extra information wasn’t really needed.  And as usual, after the phone call, all of it started working just fine.

I submitted three entries into the competition, Big Fat Phony (my favorite category 23 beer, but I hadn’t received any results yet, so these results will be quite interesting), Kuroppoi as a 5C Dopplebock (again before I had the BlueBonnet results which suggested submitting this as a 5B Traditional Block) and since I had run out of my favorite Momosuppai Peach Berliner Weiss, I substituted in one of my latest IPAs, Oops I mixed my Grains with Calpyso and Citra hops.

After viewing the results from BlueBonnet, I really wanted to see what I had submitted for ACCF.  Logging back into their competition software proved difficult.  The system had said that my password (which I store in Lastpass) was incorrect and then the kicker, while attempting to reset the password I was informed that my email address wasn’t in the system.  Oh boy.

After an email to the coordinator the real saga began.  After about three or four days of getting assurances that the webmaster was “on it”, I get an update with new login information.   I logged in to find *nothing* in the system.  None of my contact info and more shocking, none of my beer entries.  A short email back about this small minor detail and I get a response:

“Please call us as soon as possible about your entries”

I called 15 minutes later, on Sunday.  They were blunt and to the point.

“We’ve lost your entries.”

Somehow they must have been missed at the pickup point at Austin Homebrew Supply.  Or they fell off the dock at Branchline Brewing, the designated drop-off location for the ACCF.  Later that night I planned my approach.  I’d stop by AHS on Monday looking for the beers at the store.  In case they weren’t there, ACCF had said they would still let me submit three beers, but I would need to drive them down to San Antonio.

Some good could come from this as I had other beers ready, and I could replace the Big Fat Phony, which seemed too challenging for the judges in BlueBonnet brewoff.  I needed one last detail from ACCF, including where I needed to drop by beers off.

In their response, I received some grand news.  They had found my beers, and they had been judged with the rest of them.  It turned out there was some additional confusion and delay among the ACCF team, but at least for me, all is right now.

I’ll be waiting till April 20th, when the results will be posted.  Here’s hoping for no more beer competition drama.

Bluebonnet 2013 Results

Momosuppai, a sour-worted Berliner Weisse with Peaches

Momosuppai, a sour-worted Berliner Weisse with Peaches

The Texas BlueBonnet Brewoff 2013 was held in Dallas, TX March 20-23.  On Sunday night, the results were announced, even tweeted via the Austin Zealots homebrew clubs’ newly announced twitter account, AustinZealotsTX.

I had entered three beers into this competition, Big Fat Phony in category 23 Specialty Beer, Momosuppai in category 20 Fruit Beer, and Kuroppoi in category 5C Dopplebock, even though I have seven beers available.  Unfortunately, the American Homebrewers Association (AHA) rules restrict what one can enter.  For example, the rules prevent a homebrewer from submitting multiple beers to the same sub-category.  While this isn’t in general that bad, it does affect some brewers that are brewing beers don’t yet have official sub-categories.  Rye IPAs and India Black Ale (or Black IPA, or Cascadian Dark Ale) are common beers but aren’t yet recognized by the BJCP.  There is a catch-all category for these beers, 23, Specialty Beer.  I happened to have three beers that would only fit in 23 only (Black Hop Day, Fly Ralcon and Big Fat Phony).  I had to pick the best of these for category 23. I chose my favorite, Big Fat Phony.

As the results came in, I was checking to see which categories I had entered.  And while it was little disappointing, I wasn’t totally surprised that I claimed none of the medals in the categories I entered.

Later that week I got back my score sheets.  One of my biggest fears around Big Fat Phony happened.  The scores for BFF were just too low to be real (average around 20 / 50) and the sheet was marked up with “off” flavors.  Band-aide, medicinal, iodine, “you might have an infection”… If you’ve seen my post on Scotching a Beer, then you know that Big Fat Phony was scotched with an Islay Whiskey, which is known for its, wait for it… peaty flavor which is commonly referred to as “medicinal”.  So, I don’t think Big Fat Phony got a fair shake, but that’s entirely my fault for submitting an experimental beer.

The other two beers did reasonably well.  Kuroppoi scored an average of 34 points, but not enough to move on to the second round.  One judge commented that the beer didn’t have quite the “rich, malty” character that 5C requires and that I should instead just submit it as a 5B, Traditional Bock.  That’s decent feedback.

The best of the group was Momosuppai, a Fruit Beer, which was a Berliner Weiss with Peach puree.   This was my first attempt at a sour-worting and Berliner Weiss which came out really well.  It could have used a few more days to increase the sour intensity, but it was still very nice.  This beer scored an average of 36.5, and made its way to the second round, and re-scored at a 26.5.

After asking around, this lower score during second round is typical, but there is also a lot of randomness too as some members reported having a lower score in the first round, only to see a higher score in the second.

I’m still learning things from competitions and it’s fun making sure the brewing schedule works for whatever is needed for the next competition.

Off-schedule brew for competition

This year, I’ve been trying to enter at least one beer in each of the Lone Star Circuit homebrew competitions.  I entered three into the Bluebonnet Brew-off and another three into the Alamo City Cerveza Fest, but the next one, the Celtic Brewoff caught me by surprise since it has a restricted/modified list of BJCP categories.

This meant that even though I have close to 8 beers on-tap in my garage, I didn’t have anything that I could submit. I happened to have an older beer that had been aging over at my friends house available, so I ended registering one of my favorite brews, Makkuro Kurotsuki, an Russian Imperial Stout (Category 13F). But I wanted one more.

I dug through my list of recipes in Beersmith and found a lighter and easier (meaning faster) beer that had been a big hit in the past. Ed’s Best Bitter.

Ed's Best Bitter fermenting at 68F

Ed’s Best Bitter fermenting at 68F

Now that I had my recipe selected, it was time to brew. I normally brew twice a month on a Friday night. I invite a bunch of my friends, some who help out and others who come to enjoy the show and drink some homebrew. However, I couldn’t wait if I wanted this beer to be done in time for the competition.

So I did a complete brew, from grain to fermentor including the cleanup in about 4.5 hours. Starting at 8PM when the kids go to bed, my head hit the pillow at 12:30.

Not bad without any help.

The brew session went as expected. Targeting a mash pH at room temp (25C) of 5.5, I ended up with 5.4 @ 23C. Pre-boil gravity was a few points low (1.033 instead of 1.035) and subsequently, O.G was as well, 1.045 instead of 1.048. But that works out OK since the style is meant to be lighter in alcohol.

Here’s the recipe

Recipe Details

Batch Size Boil Time IBU SRM Est. OG Est. FG ABV
5 gal 60 min 27.8 IBUs 9.2 SRM 1.048 1.013 4.5 %
Actuals 1.046 1.01 4.7 %

Style Details

Name Cat. OG Range FG Range IBU SRM Carb ABV
Special/Best/Premium Bitter 8 B 1.04 - 1.048 1.008 - 1.012 25 - 40 5 - 16 0.8 - 2.1 3.8 - 4.6 %


Name Amount %
ESB Pale Malt (Gambrinus) 8.25 lbs 91.03
Crystal, Medium (Simpsons) 13 oz 8.97


Name Amount Time Use Form Alpha %
Goldings, East Kent 1 oz 60 min Boil Pellet 5
Fuggles 1 oz 15 min Boil Pellet 4.5
Goldings, East Kent 1 oz 0 min Boil Pellet 5


Name Amount Time Use Type
Calcium Chloride 5.40 g 60 min Mash Water Agent
Gypsum (Calcium Sulfate) 3.10 g 60 min Mash Water Agent
Epsom Salt (MgSO4) 0.40 g 60 min Mash Water Agent


Name Lab Attenuation Temperature
London ESB Ale (1968) Wyeast Labs 69% 64°F - 72°F


Step Temperature Time
Saccharification 152°F 75 min
Mash Out 168°F 10 min


Bru'n Water calculates a mash pH of 5.5
Did a 1L starter of 1968 24 hours before pitch.

2013-03-24 — Measured gravity after 4 days, 1.016 with activity still going, hoping to hit 1.011 or 12 by Wed, 2013-03-27.
2013-03-26 — Measured gravity after 5 days, 1.012, start cold crash
2013-03-27 — Racked 5 gallons into keg, force carbing to ~2 volumes of Co2.