By Mike Billy – Mid West Beer Blog
For the first time since the brewery started making bourbon barrel aged beers in 1992, Goose Island is offering refunds for the two variants that have developed “off” flavors since bottling.
Granted, the company is handling the issue exceedingly well. The refunds have been going smoothly and Goose Island is not asking for receipts or for the empty bottles to be returned.
And having one batch with off flavors in 23 years is a testament to the quality control the brewery has in place.
The 2015 Bourbon County Brand Coffee Stout I opened near the end of November tasted great. That indicates at least some off the bottles weren’t experiencing a problem. I have two more so we’ll see how those turn out, as well.
But the bottles that did have problems have been described as having “sour” flavors by reviewers on websites like Untappd.
Goose Island, however, is ruling out an infection. According to Porch Drinking, the beers are not “technically infected” because there were no bacteria detected by Goose Island’s lab testing.
On the other hand, the company’s own blog post said, “It has come to our attention that since bottling the 2015 Bourbon County Coffee and Bourbon County Barleywine, they have developed flavors that are not consistent with our expectation of how these beers should taste.”
Obviously, I’m not privy to what caused the off flavors in the Goose Island’s Bourbon County beers this year. But for off flavors to develop overtime — especially sour flavors — is usually an indication that bacteria like lactobacillus or pediococcus ended up in the beers.
To understand why, you have to understand the process of how beer is made. In short, malts are combined with hot water to create a sugary liquid called wort. After the wort is boiled, hopped, and cooled down, yeast is pitched. The yeast eats the sugar and creates CO2 and alcohol.
When bacteria is introduced, either intentionally or unintentionally through the environment, it eats the sugar and creates acidic, or sour, compounds like lactic acid. What’s more, the bacteria can eat complex sugars that brewers yeast has trouble with. So anything that is leftover from the primary fermentation with brewers yeast can be broken down by bacteria or wild yeast.
By the way, those bacteria aren’t harmful for human consumption. In fact, they are typically used when making beers that are intentionally sour, like a Flanders red or a Berliner weisse, Lactobacillus also is used in making yogurt and probiotics.
This isn’t a unique problem that Goose Island faces, either. Barrel aging a beer is a tricky skill and breweries are always battling with possible infections.
Part of the problem is the resiliency of lactobacillus and strains of wild yeast like brettanomyces. According to Mitch Steele’s IPA book, brettanomyces and bacteria can burrow up to .3 inches into the barrel’s wood, which can make those microbes more resistant to sanitation processes.
Imperial stouts and barleywines typically have a lot of complex sugars leftover after the primary fermentation. When those beers are added to the barrels the bacteria and wild yeast, if present, could make their way into the beer and cause an unwanted sour flavor or other off flavors.
When these sour flavors unexpectedly develop in a beer, brewers often call those beers “infected.” It’s not a term that is used to describe the beer as dangerous. It’s just the term to describe the presence of unwanted bacteria.
“Contaminated” is another word that is used and it is the preferred word that is taught in the Beer Judge Certification Program.
To reiterate an earlier point, Goose Island is saying their beers are not infected. An email from a company spokesperson made that clear saying, “The beer is not infected. Infected would imply a bacteria problem or cause for safety concern. It simply is off profile taste.”
I am curious to see what the brewery’s additional tests will uncover because a sour flavor, in many cases, is an indication of an infection. This case has potential to shed some light on other causes of this particular off flavor if the information is released.
If you purchased a bottle of the barleywine or coffee stout that is infected you can get a refund by calling 1-800-GOOSE-ME. The deadline to get a refund is Feb. 29.
Photo: A lactobacillus culture / Wikipedia
So it must be brettanomyces by ruling out bacteria…
I’ve seen a microscope slide of a BCBW that had lacto in it.