I was recently in Dublin, Ireland as a sponsor of the European Beer Bloggers Conference and had the opportunity to go on an excursion to Guinness’ St. James Gate Brewery. Besides getting to see Guinness’ brand-spanking-new brewhouse, we went on a personal tour led by Master Brewer Fergal Murray, had a beautifully paired beer dinner, and ultimately had the opportunity to sit down with Fergal and a handful of Guinness brewer/engineers for a Q&A session. Of course, being in a room of all the top European beer bloggers you can be assured that no punches were pulled in the questions for this elite crew. Unfortunately, I was ill-equipped to record the questions or answers, but I did retain a handful of key responses for the topics that I often hear homebrewers chattering about. Here they are in no particular order:
— Reuben Gray (@TaleOfAle) June 27, 2014
Key finding #1 – Guinness does use a sour blend for their stout
No ratios or processes were described, but the brewers did cop to the fact that part of the key feature of Gunniess Stout was a sharp acidity contributed by lactic acid. A simple fact of brewing history is that almost every beer before the late 1800’s was populated with all sorts of non-saccharomyces organisms; since Guinness has been brewing for such a large span of history it’s to be expected that a bit of that “infected” character is a part of the recipe. My hypothesis, however, is that Guinness uses food-grade lactic acid instead of a separate sour mash (or other souring operation).
Perhaps you’ve seen this quote around: “…they have a series of huge oaken tuns dating back to the days before Arthur Guinness bought the brewery, which they still use as fermentors for a fraction of the beer. The tuns have an endemic population of Brettanomyces, lactic acid bacteria and Lord knows what else, and beer fermented in it sours emphatically. They pasteurize this and blend small quantities of it with beer fermented in more modern vessels.” (confession: I don’t know the attribution of this quote, but I’ve seen it repeated extensively), but I don’t think there’s much of a chance of anything other than saccharomyces being in the new brewhouse. Also, consider the volumes at which Guinness churns out their beers: it would be difficult to consistently produce the kind of character they’re looking for from their latent cultures.
Key finding #2 – Guinness mashes their roasted grains separately
The process the brewers described sounded very similar to the popular “cold steep” method many homebrewers employ for roasted grains: a separate mash (hot or cold, I don’t know) is used to extract the color and roastiness out of the roasted barley, which is then blended in to the separately-mashed base wort. This makes sense, as a pint of Guinness has very little astringency as compared to it’s high SRM.
Corollary: this blows away that the idea that water super-high in carbonates (e.g. Dublin water) is required to make a world-class stout. That was probably true in the days before water chemistry was well understood and when all the grains were mashed together, but I’d wager they use R/O or highly processed water and add the salts they want for their base mash now.
Key finding #3 – Guinness brews high-gravity
Maybe this one isn’t so much a revelation, as lots of big breweries do this, but Guinness actually brews most of their stuff to a high gravity (~1.070) then dilutes it down to lower ABV depending on what they’re packaging. This also gives them the benefit of churning more beer out from the same amount of fermentor space. I can’t recall if I heard this at the Q&A or if I heard it from elsewhere, but I believe the Foreign Extra Stout is essentially just the undiluted product that Guinness Draught is made from.
So there you have it, some juicy facts from a fun excursion. Aside: if a Beer Blogger’s Conference is happening near you (the US conference is in San Diego for 2014) and you have even an inkling of attending, I really do recommend checking it out. As a “Citizen Beer Blogger,” i.e. non-sponsor or industry pro, the price is the bonkers low and the weekend is packed full of great activities. In the mean time, check out the photostream of the EBBC14.
— The Church Cafe Bar (@thechurch_ie) June 28, 2014