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Thursday, September 08, 2011

BrewDog's Ghost Deer--Too Strong to be True?

Somehow I missed the latest gonzo marketing blitz from the lads at BrewDog. (That may be a downside of always keeping the volume at 11.) In July, they announced another super-strong beer called Ghost Deer that came with all the unusual bells and whistles we associate with BrewDog:
Ghost Deer is a 28% fermented beer, the strongest ever fermented beer.... After fermentation it is aged for 6 months in some amazing whisky, bourbon, rum and sherry barrels. There is only one Ghost Deer head and this beer will only ever be available on draft, served in a stemmed glass, direct from the mouth of the deer himself.
That business about the deer is of course literal--it pours from the mouth of a taxidermied deer head. The release was accompanied by one of the brewery's famous videos, which tells the tale of the ghost deer and manages to advance the brand brilliantly.

All well and good. But here's the thing: 28%?? Can this be? If BrewDog has managed to ferment a beer to that level, it would be a towering achievement. They report using three yeast strains to get there, but I've never heard of any yeast that comes close to tolerating that level of alcohol (White Labs and Wyeast strains top out at 18%). Beer has complex sugars that yeasts have a hard time digesting at final gravity, so even if you found a yeast strain that could go that high, I don't see how it could munch through the maltotriose to get down to that level. It seems to me that if BrewDog managed to create a beer of 28% strength entirely from fermentation, it would represent a radical advancement--one far more impressive than taxidermied deer heads.

Any sciencey types out there willing to shed some light on this? Is BrewDog polishing the apple here, or is it really possible to tease 28% alcohol out of the hardest-working fungi in the beer world?


  1. Surely the multiple barrel ageing significantly contributes to the strength...

  2. The 2009 batch of Samuel Adams Utopias was 27.0%. To my knowledge Utopias is not iced and is entirely barrel aged.

    I also believe that earlier batches of Dogfish Head 120 Minute were 20.0% or 21.0%

  3. Bill "too cynical for his own good" Schneller3:01 PM, September 08, 2011

    Generally, gimmicky high alcohol beers like this have to be brewed in stages. You don't brew a base beer with enough sugar to make a 28% beer. You brew one to 10-14% or so, and then keep gradually feeding it until you reach the desired, ridiculous level of alcohol that let's you claim it as a new world record and a mile stone of brewing innovation. 28% beer? Whatever.... But I guess it's beer that's meant to be collected, not consumed.

  4. You didn't miss it. You just misread the non-American date format. It was announced yesterday, the seventh of the ninth, two thousand and eleven, or 07/09/2011, per the blog header.

    And I'm with anonymous. I smell grogging.

  5. Aye, what Bill said. Many of the stronger Belgian brewers incrementally feed beet sugar to their beers during the fermentation process.

    DFH uses many small sugar additions over several days in 120 Minute. I believe Jamil's clone recipe for 10 gallons included 33lbs of grain and 22lbs of corn sugar, added in 12oz increments, twice a day.

    FYI, white Labs Super High Gravity Ale Yeast (WLP099) is listed as able to ferment up to 25% alcohol

    Beer and Coding

  6. Excellent: hive mind to the rescue. It's nice to know that if I ever have a beery question, someone smarter than me will sort it out. Including, thanks to the Beer Nut, the business about dates.

  7. @Anon - As I think I've posted here before, the effects that barrel-aging spirits have on strength are complicated and due to a number of factors. As these yahoos brew in Scotland, I would expect (although who knows) that if they age their beers in something akin to a scotch whisky dunnage warehouse, the spirit should actually get weaker. This is due to the cooler climes in Scotland causing a relatively low evaporation rate for water, but higher for the more volatile alcohol. In Kentucky, where they make bourbon and it is warmer year-round, spirits actually become STRONGER in the barrel as the rate of evaporation of water is higher. There are a number of other factors like the specific warehouse a barrel is stored in, or even where in that warehouse it is. If you want more reading on the subject, I can't recommend Michael Jackson's "Whiskey" highly enough.

  8. The other question is: what does stressing yeast up to that ABV do to flavour?

    Im guessing bad things.


  9. Mark, if this beer is anything like their Tactical Nuclear Penguin or Sink the Bismark, then they are in no way concerned about flavor, both were just horrible in my opinion.

  10. @Paul: I think anon's point was that aging beer in a barrel previously used for strong spirits is likely to increase the strength of the beer, an effect The Beer Nut appropriately referred to as 'grogging'.

  11. Indeed! I always wondered about this. Presumably the barrels are empty and dry, can they still contribute alcoholic content from remaining spirit in the barrel? OR are we referring to surreptitious addition of stronger spirits? I think that there were rumors of addition of grain alcohol to the extra-strong batch of WWS back in the day...