Channelling the ghost of Sir Arthur Guinness: Brewing a Guinness Irish Stout…

Without a doubt, Guinness is one of the world’s most recognizable beers. Not only is it one of the most recognizable, it has almost, single-handedly, eradicated almost every other beer in it’s style to become what seems to be the only apparent example of a Dry Irish Stout.

Guinness’s brewing history dates back to the early days of Porter, whereby the story of Porter and Stout are inextricably linked. Stout originally referred to a stronger version of Porter. The term “Stout Porter” would have been  synonymous with the brown beers, letting the consumer know of the relative higher gravity to which it was brewed. In it’s heyday, Porter would have been brewed with mostly, if not all, brown malt. With the advent of “Black Patent Malt” in 1817, brewers then had another option for making the highly popular beer. What they found was that they were able to use a grist of mostly pale malt and enough patent malt to get the same colour. Pale malt has a much higher efficiency than brown malt does, so they could use less grain, thus lowering their production costs. When roasted barley came on the scene, brewers had yet another option to use when brewing their porters and as such, the divergence of porter and stout began.

Another wedge driven between the two beers  is the water. Most of the world’s beer styles developed because of the natural chemistry of the water with which it was first brewed. The water of Dublin is higher in bicarbonates than London, making it quite alkaline. This gives the brewers of Dublin the ability, nay, the necessity, to increase the percentage of darker, more acidic, roasted grains in order to achieve the proper pH in the mash. Something I also learned from watching a video from Brewing TV, it was illegal in England at the time to use unmalted grain for brewing. The government used to tax malt and therefore required brewers to use only malted grains. In comparison the brewers in Ireland didn’t have this restriction. Combine all these factors with a couple hundred years of brewing evolution, and you have the stout we know and love today.

The history is rather vague and we only have access to a certain amount of information, but from what I’ve researched, this makes the most sense to me.

As stated, Guinness is undoubtedly the premier maker of dry Irish Stout. It is the dream of many a homebrewer to concoct one of these magnificent brews and serve it to their friends with chest proudly upwards. Unfortunately, Guinness does not allow us to peer into the darkness so easily, as it proves to be one of the more elusive beers to brew. They understandably guard their process closely, as letting people in on their secrets could slowly chip away at their world domination.

We may never know how to exactly pull off a proper Guinness Stout, but I will attempt to shine a light into the abyss.

First thing we need to look at is the water. Dublin’s water has without a doubt a significant effect on the resulting beer. We don’t exactly know if, or how Guinness treats their water, so we will have to guess at that. A good starting point is to adjust your water to a referenced mineral breakdown of Dublin water. I will use the values from Bru’n Water which has proven to be a fantastic reference tool for calculating water adjustments. The following values are what it suggests for the Dublin profile:

  • Calcium: 120 ppm
  • Magnesium: 4 ppm
  • Sodium: 12 ppm
  • Sulphate: 55 ppm
  • Chloride: 19 ppm
  • Bicarbonate: 315 ppm

Now if you’re not at the point where you’re adjusting your water, do not despair. If you’ve been brewing good beers up until now, just go with it, I’m sure it will be fine.

NOTE: For experiment’s sake, this batch will use my existing water profile, without any adjustments, to use as a ‘baseline’. In the subsequent batches, I will add the salts to see exactly what impact they have on the resulting beer.

As for the grist, I’m going to assume they would use a premium English malt such as Maris Otter. We know roasted barley is the proper ingredient to use for that dark, roasted, bitterness that is synonymous with Guinness stout. A trick I’m going to employ is something I read in Jamil Zainasheff’s – Brewing Classic Styles. He says, the only way to get that true stout flavour and colour is to crush the roasted barley as much as possible, ideally to a fine dust in a coffee grinder. Jamil hasn’t led me astray yet, so I’ll try his suggestion. From reading Designing Great Beers by Ray Daniels, along with Radical Brewing by Randy Mosher, flaked barley is used to give Guinness that smooth, creamy mouth feel. (Another trick Guinness uses to achieve this, is by using a special tap that utilizes a CO2/nitrogen mix to produce smaller bubbles in the beer, giving it a rich creamy head and smooth texture, as opposed to the sometimes harsher pure CO2.)

Guinness is a dry stout, so you don’t want any residual sugars left when fermentation is finished. Some recipes will have crystal malt in them. Crystal malts add unfermentable sugars to the wort, which is fine for other types of stout, but it’s not what we want in a dry Irish Stout. An Irish ale yeast such as Whitelabs #WLP004, or Wyeast #1084, will ferment with a low level of esters, but you will need to control your fermentation in order for them to fully attenuate. Another trick from Jamil is to use a neutral, more attenuative strain like Whitelabs California Ale #WLP001 , Wyeast American Ale #1056, or Safale US-05 to ensure it finishes dry.

One elusive element of Guinness, is what people often refer to as the ‘twang’. Porters in the early days were commonly left to age up to a year or more, developing a pleasing sourness due to the likely inoculation of Brettanomyces bacteria that would have undoubtedly been present in the large wooden vats it was stored in. Brewers and pub owners would regularly mix this aged (stale) beer with younger and fresher (mild) beer. One reason would be to improve the taste of the beer, and secondly, it takes an enormous amount of space and an enormous amount of investment to store and age huge vats of beer. So if they could mix some in with a younger, less aged beer and get pleasing results, all the better for the bottom line.

Apparently this is a technique that Guinness uses to this day. We as home brewers may have a tricky time replicating this, but I’ve read about a couple different ways to emulate it. First, is to make a sour mash.  Set aside a small amount of unfermented wort from your mash (say 1/2 gallon). Add some freshly crushed grain to it and leave it out on the counter to sour. (The lactic bacteria naturally present in the  grain will get this process going) Be sure to cover it with a paper towel or cloth. It may develop a bit of ‘scum’ on the top after a few days, but you can just skim this off, and when ready, boil it for 15 mins to sterilize it. Then it can be added to your fermentor to get the desired level of sourness. The second option, which I find would probably be much easier, is to add a small amount of acid malt to the mash to give it the desired acidic twang.

NOTE: Again, I’m just going to go with Jamil’s basic dry stout recipe this time around and introduce some changes in the next batch.

I’m going to employ a double infusion mash to give me two steps. The first step will be at 122°F for a short 15 minute protein rest to allow the flaked barley to become less viscous and make it easier for sparging. Then with the second infusion, I will bring the mash up to a saccharification rest at 152°F, which should provide us with a largely fermentable wort.

Here is what I’ve come up with based on Jamil’s recipe for a dry Irish stout:nd Storage

Hoptomology’s Guiness Irish Stout Clone – All Grain

Dry Stout

Type: All Grain Brewer: Hoptomology
Equipment: 7.5 Gallon Stainless Steel Pot + 5 Gallon Coleman Cooler Mash Tun
Est Original Gravity: 1.042 SG Measured Original Gravity:
Est Final Gravity: 1.009 SG Measured Final Gravity:
Estimated Alcohol by Vol: 4.3 % Actual Alcohol by Vol:
Bitterness: 41.0 IBUs Bitterness Ratio: 0.976
Est Color: 28.8 SRM Calories: 0.0 kcal/12oz



Amt Name Type # %/IBU
5 lbs 5.3 oz Pale Malt (2 Row) UK (3.0 SRM) Grain 1 70.1 %
1 lbs 8.4 oz Barley, Flaked (1.7 SRM) Grain 2 20.0 %
12.0 oz Roasted Barley (500.0 SRM) Grain 3 9.8 %
1.748 oz Goldings, East Kent [5.00 %] – Boil 60.0 min Hop 4 41.0 IBUs
1.0 pkg Safale American (DCL/Fermentis #US-05) [1.70 oz] Yeast 5
Total Grains Used: 7 lbs 9.6 oz Total Hops Used: 1.748 oz

Mash Profile

Mash Style: Double Infusion, Medium Body
Brewhouse Efficiency: 81.00 %
Mash Steps

Name Description Step Temperature Step Time
Protein Rest Add 1.78 gal of water at 137.7 F 122.0 F 15 min
Saccharification Add 1.53 gal of water at 200.6 F 152.0 F 60 min
Mash Out Add 1.53 gal of water at 210.0 F 168.0 F 10 min
Sparging: Fly sparge with 2.49 gal water at 168.0 F to achieve 6.16 gal

Boil Profile

Boil Size: 6.16 gal Boil Time: 60 min
End of Boil Volume: 5.46 gal Estimated pre-boil gravity: 1.036 SG
Batch Size (into fermenter): 5.00 gal Measured pre-boil Gravity:
Final Bottling Volume: 4.80 gal

Fermentation Profile

Fermentation: Ale, Single Stage
Primary Fermentation: 10.00 days at 68.0 F
Secondary Fermentation: 0.00 days at 0.0 F

Carbonation and Storage

Carbonation Type: Keg Volumes of CO2: 1.8
Pressure/Weight: 4.66 PSI Age Beer for: 3.00 days
Keg/Bottling Temperature: 40.0 F Storage Temperature: 34.0 F


Taste Rating: 0.0 / 50
Taste Notes:
Other:  *** CRUSH RAOSTED BARLEY TO A FINE POWDER USING A COFFEE GRINDERDownload Recipe: Hoptomology’s Guiness Irish Stout Clone – All Grain – A little about life, a lot about beer.

Read the review here: Reviewing my Guinness Irish Stout…

Read the review to the revised version (version 1.1).



20 Responses to Channelling the ghost of Sir Arthur Guinness: Brewing a Guinness Irish Stout…

  1. I’ll be curious to see your results. I did Jamil’s recipe last year, but used Wyeast 1084 and Fredericton water. I wasn’t super-happy with the results, but the FG came in too high (I believe it was 1.013), so it wasn’t really much of a DRY Dry Stout.

    Hope yours turns out better!

    • That’s too bad. First time I’ve brewed a dry stout, so who knows what will happen. I’m sure I’ll have to get into the water adjustment and some acid malt with it. My neighbor is getting me some beer gas (CO2/N) which I’ll try on it as well. I’ll let you know how it goes….

  2. Sounds like a fun experiment. Can’t wait to hear the results!
    Are you just going to use a really thick mash for the Protein rest? What do you figure the mash thickness will be for Saccharification?

    I’d be tempted to lower your Sacc temp even lower. 149F maybe?

    • Cheers Craig,
      I’m a little concerned though. I switched over from using Irish Moss to Whirlfloc tabs, and for my last 2 batches using the tabs, it’s like somebody sucked the life out of my beer! very strange, but left them very empty and stole the hops. I’m not sure if I did something else that would have messed it up, but hopefully it didn’t do that to the stout. I’m curious to add some acid malt (I’ve never used it before) and adjust the water in the next batch. My buddy is also getting me a can of beer gas (CO2/N) so I’ll play with that as well. Just watched an episode of “Mega Factories” and it was profiling the immensity of the Guinness brewery, do a search and give it a watch if you’re interested (google videos / youtube)
      You may be right on the lower mash temp, I think I did that to hit the final gravity to get me 4.3%, which I think is what Guinness draught in the can is. I’ll see where I end up and adjust for the next batch.
      Was my first time doing a double infusion, so hopefully it was ok. Mash was 0.9qt/lb for the protein rest and came up to 1.7qt/lb for the sacc. rest.
      Not 100% why the protein rest, because I’ve read that the beta-glucan rest is more between 98 -113F.
      From “How to Brew” he states: “The typical Protein Rest at 120 – 130°F is used to break up proteins which might otherwise cause chill haze and can improve the head retention. This rest should only be used when using moderately-modified malts, or when using fully modified malts with a large proportion (>25%) of unmalted grain, e.g. flaked barley, wheat, rye, or oatmeal.”
      You have much experience with using a protein rest? I want to make a belgian wit soon, and Randy Mosher swears it’s the only way to get a true wit character out of the grain….

  3. While I have never used a protein rest, I would certainly consider one if using unmalted grain over 20%. In this case, I think it’s appropriate for both the dry Stout and the Wit.

    For stepping the mash, the method you’ve described seems easiest, plus you will be left with a fairly lose mash which will (apparently) leave you with a more fermentable wort. The alternative would be to mash at your standard qt/lb, do your protein rest, draw some of the mash runnings, heat, add back to the mash to bring up to sacc temps. I like the first, seems easier and more to the point.

    I have never used so much unmalted grain in a recipe so I have no idea how this will attenuate. I have fermented an oatmeal stout with with US-05, it finished attenuation at 72%. I mashed hot, around the 154F range.

    Regarding Whirfloc, I have never brewed without it, so maybe I am missing something and don’t even know it? I have read numerous articles which claim beers brewed with almost all the cold-break removed, are perceived to have less character and body. Cold break is also a yeast nutrient. Whirlfloc fluffs the cold break, if you rack wort from the BK to primary as clear as possible, maybe you’re not getting ENOUGH cold break into the fermenter? Another thing I have noticed with Whirfloc, it makes whirlpooling (to get trub and hop gunk to cone in the centre of the BK) almost impossible. The cold break is too fluffy to join the centre pile.

    All that said, I would even use whirfloc in a stout.

  4. Damn, that should have read:

    “I wouldn’t even use Whirfloc in a stout”

  5. Sorry for the spam, when I use whirlfoc, I add it with 5 minutes left in the boil. I brew about 26L, so I only use 1/2 a whirfloc tab.

    I read a post from the manufacture of Whirfloc on an UK brewboard, they were surprised it was being used by homebrewers. The “Whir” part of the name refers to it’s intended use in commercial breweries during the whirlpool phase, post boil. 1 tab is enough for 20 gallons of beer. Adding it at 15 minutes left in the boil will denature the product and render it virtually useless. I think I may even cut my usage down to a 1/4 tab.

    • Interesting. True enough, I probably didn’t even need it in the stout. I think I actually used 1/2 tab in the other 2 brews that went strange, maybe it pulled out too much. (?) I’ll make sure I use no more than 1/4 tab, and I also read about adding at 5 mins, so I’ve been following that. I use a counterflow chiller, so I end up with plenty cold break in the carboy, so that part should be fine. It was of different quality than the flaked irish moss, and considerably more clear. I’ll have to mess with it some more to see what’s up.
      Good idea on pulling some runnings and heating it up to add back for your second rest, but yeah, just going thick and adding more water to bring it up seems much easier, and as you say, you end up with a thinner mash and hopefully a more fermenatble wort.
      We’ll see how it goes, lots up in the air with this one. To be honest, because of all this, I’m not expecting much from it, more of a test run, then I can adjust it for round two.
      Will let you know.
      Thanks for your input!

  6. I just watched the mega factories vid. Part 3 on Youtube. The brewer states that the Guiness Factory is blessed with soft water… uh, what?!?!?

    • I know eh? WTF?!
      My guess is that they’re trying to throw people off the trail as they’re so secretive about their process. Like the “Secret Room” where they have their “Secret Ingredient”.
      I’m guessing it’s the soured wort.
      I doubt you could brew such a dark beer with soft water unless you treat it heavily, and that would add cost to production.
      But that’s just my guess…

  7. I brewed an English Dark Mild yesterday, 1037OG, 25IBU, S04 yeast. Mashed @ 156F while I went to work. Mashed-out 8hrs later, sparged & boiled (65min) as normal. We shall see how this attenuates, hopefully not too dry.

    Anyways, 1/4 tab Whirfloc @ 5min, chill and then whirlpool. Left to sit for 30 minutes. I managed 24L (~6gal) into the fermenter which is about 2 -3 litres more than I normally get. Wort was clear into the pail. I did get a small trub cone in the centre of my boil kettle. This recipe was low on hops, will try again for a planned APA.

    • wow, an 8 hour mash!
      I’ve only done a few milds and they all under attenuated (Seems to be happening a lot to me lately) so they were quite watery. Let me know how it turns out.
      Tasted the stout yesterday. Very nice balance of flavours, but I can’t help but think that the whirlfloc stripped a bit out. Still needs to finish, was at 1.015, so I mixed up the yeast a bit.hopefully tat will bring it down the lat few points, but was very good, not Guinness, but a good dry stout. I’m looking forward to adjusting the water and especially adding the acid malt…

  8. When a yeast under-attenuates, it would leave the beer with more (unused) sugars and thus increase body. With my Mild, I am hoping for a 65-70% attenuation leaving enough sugar to give body to such a light beer (3.35 ABV). My concern is that a long mash generally leads to a more fermentable beer and thus I will achieve attenuation beyond my desired 70%.

    In the case of a dry stout, I would likely want the max attenuation a particular yeast strain can provide. Given proper mash and fermentation variables, US05 should it high 70’s to low 80’s. What are you at now with 1015? How much lower do you want to go?

    • True. I guess I’m focusing too much on the ABV and finding when it under attenuates, it tastes thin, perhaps it’s another issue I’m having.
      It seems to be happening a lot lately. I bought some yeast nutrient to try out to see if that helps. I added it to my last batch of porter and it exploded in fury. The yeast was very happy about it. lol

      Yeah, it’s at 1.015 right now. I’ll check again tonight when I get home. It’s been 11 days now which is usually enough. Beersmith estimates it to go to 1.009. It doesn’t taste sweet at all, actually quite nice. I figured it would go more with the US-05. Am I missing something?

      It did cross my mind, not mashing out and leaving it overnight, because as you say, as the temp drops, it will give you a more fermentable beer….

  9. “Yeah, it’s at 1.015 right now. I’ll check again tonight when I get home. It’s been 11 days now which is usually enough.”
    Sounds pretty similar to what happened with my Dry Stout… high FG, but the beer itself didn’t taste too sweet or anything. I think I was actually kind of pleased with the flavor, just wish it came out a bit drier.
    Maybe I’ll try to send one of the last few to you, so you can compare…

    • Yeah, funny. Any ideas why the FG ended up high? Mine tastes good as well, just thought it would go lower because of the estimate of 1.009 in beersmith.
      If you have any left, that would be great!
      I have 4 beers on the go right now, when they’re bottled up, I’ll send some out to you to try…

      • Does Beersmith take into account mash variables as well as extract potential when estimating attenuation? I was under the impression it only looked at the yeast strain and plugged in an “average” number.

        Case and point, my US05 American Stout finished at 1018 or 72%. Using so much unmalted grain in a recipe, I don’t think you can expect full attenuation.

        • Come to think about it, it was PacMan yeast I used in the stout, which is suppose to attenuate even higher!

        • Good point. I’m guessing it just looks at the yeast strain and plugs in an average number. Regardless of what the malt bill is, it usually puts US-05 around 1.008-1.010.
          Maybe 1.015 is where it will be for this batch. I haven’t had the chance to check it the last 3 days, but I’ll see where it’s at tonight and probably rack it. I’m anxious to get some poured!

  10. Pingback: Reviewing my Guinness Irish Stout… | Hoptomology

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