Article

The Dark Secrets of Stout

Offer a beer drinker a stout and you will find that most have some idea of what to expect. Many will brace in preparation for a sensory battle with a strong, bitter, black ale. Others will become warm just thinking of the full, roasted, chocolate and molasses flavors in their imaginary pint. And a few drinkers may get a little randy, anxious for the purported aphrodisiac to kick into gear!

So how can one beer style be so many different things to beer consumers? The answer is simple — “stout” is really not a beer style. This may sound blasphemous to style gurus, but my point is that stout is just the tip of the iceberg of a whole family of beers. The fascinating history of stout, not a focus topic for this article, is well documented in Michael J. Lewis’ book “Stout” (1995, Brewers Publications). One of the earliest references to a “stout” beer was in a 1677 Egerton manuscript with “We will drink to your health both in stout and best wine.” This reference to stout as a beer grew over the ages into what we now  know as stout.

Today’s beer consumer has access to a wide variety of stouts ranging from the rather low-alcohol Irish dry stout to the heavy, luscious imperial stout. At the 2004 Great American Beer Festival, the word “stout” was used in conjunction with “coffee,” “foreign export,” “oatmeal,” “sweet,” “milk” and “bourbon barrel” to describe the large stout clan of beers. I don’t recall any oyster stouts this year! The one thing all of these beers have in common is color. Most stouts also have the same “blood type,” usually ale, although many commercially available stouts are fermented with lager yeast. Suffice it to say, not all stouts are created equally.

It’s All in the Grain!

The common denominator of stout is obviously its color. Most brewers focus on the dry Irish stout when contemplating the style. The grain of choice with this type of stout is roasted barley. Exactly why this is, I do not know, but the use of roasted barley lends certain traits to the style. Maillard reactions that occur during kilning malt are drastically reduced when barley is roasted because the necessary ingredients for the reaction — reducing sugars and free amino nitrogen from amino acids — are very low in barley. This means that roasted barley and roasted malt are quite different. Stouts brewed from roasted barley typically have a dense, white head and do not have the level of acrid, burnt, roasty flavors (many of which are Maillard reaction products) found in stouts brewed with roasted malt.

Roasted malt is a mainstay for some stouts, especially bigger ones, and imparts flavor and color attributes that are different from roasted barley. Stouts using this grain often have a darker head of foam than those brewed with roasted barley and usually have more roasted, coffee-like flavors. I have found great success using Weyermann Carafa III, a de-husked roasted malt that lacks the sharp acrid flavor of regular roasted malt. For such a broad family, it only goes to reason that more than one malt type is used for color and flavor of stouts.

Although a quick perusal of stout commentary on the web finds many sources denouncing the use of crystal malt in the style, many commercial stouts do indeed use such malts. Crystal malts lend caramel and toffee notes to beer and are a useful ingredient when sweetness and higher finish gravity are sought. Personally, I like to use crystal malt in coffee stout and imperial stout to add depth of body.

Chocolate and other “light” roasted malts can also be part of the stout brewer’s arsenal. I strive for balance in my beers and these grains fill in the middle of many stouts. A stout brewed exclusively from roasted barley or malt may lack the richness of flavor that malts such as chocolate and brown malt lend. This may be read as an attempt to morph porter and stout, yet the fact remains that many stouts have more depth of body than that obtained by using only one type of dark grain.

Whatever dark grain or combination of grains is chosen for the brew, the amount used in stout brewing hovers around 10% of the grist bill for normal gravity stouts. This percentage usually decreases in higher gravity stouts. This heavy dose of roasted grain is legendary for causing headaches during wort collection, especially when roasted barley is used. Brewers use special techniques, really just brewing tricks, to make this task easier. Brewers using infusion mash tuns often add the dark grains last so that they are top of the mash bed.

Lager brewers typically use mash mixers and lauter tuns and cannot sprinkle the dark grains on top of the mash bed because everything is mixed up in the mash mixer. Dark grains are very brittle and add a lot of fine particles to the mash, which makes wort collection troublesome. We have a mash mixer at Springfield Brewing Company and I have tried all sorts of brewing tricks to improve wort collection when using roasted grains.

One particularly effective trick is to leave the roasted grain out of the mash and to use an extract. For a while we were making our own extract from roasted barley and adding it to the mash so that the fine particles would be absent during wort collection. This worked great, but took too much time. We eventually replaced roasted barley with de-husked roasted malt and our major headaches were eliminated.

The most famous stout in the world uses a liquid extract, called Guinness Flavor Essence (GFE), to convert pale lagers and ales brewed by licensed Guinness producers around the world into Guinness Foreign Stout. GFE, reportedly a mixture of roasted barley extract and special beer, is only made in Dublin and is used by breweries in the Caribbean, Africa and Asia. According to a Guinness web site, all Export Stout was brewed in Dublin up until 1962, when licensing agreements were set up with local brewers in key markets.

Stouts are usually made from a base of pale, 2-row malt and often times include flaked barley as an adjunct grain. Based on personal experience, I do not feel that flaked barley is a “must” for a good stout. The reasons for its use on a commercial scale have more to do with economics than flavor. Flaked barley is one of those grains that has a high potential for causing aggravation during wort collection. Many of the higher gravity stouts incorporate liquid sugar adjuncts to help boost the initial gravity.

The Other Ingredients

Roasted grains not only add color and flavor to stout, they lower the pH of the mash. Although pH reduction is not necessarily a bad thing in brewing, roasted grains push the pH below 5.2 when low carbonate brewing water is used. Historically, stout and porter flourished around Dublin and London, respectively. Both cities have similar water chemistry with a calcium concentration around 100 mg/L and about 150 mg/L of carbonate. This type of water works great because the carbonate helps balance the acidity of the roasted grains and brings the mash pH back into the 5.2 to 5.4 range.

Water chemistry is a huge topic unto itself and adding salts to local water to mimic Dublin water can be very difficult. The recipes I give on page 41 take the easy way out and I suggest an addition of baking soda (sodium bicarbonate) to help balance the acidity of the roasted grains.

Most stouts have medium to high bittering levels but minimal hop aroma. In fact, many commercially brewed stouts only use bittering hops in the form of pellets or liquid extracts. American craft brewers, of course, do things a bit differently and many of our  stouts are very hoppy from a generous dose of aroma hops in the kettle. My personal preference mandates late hopping with a variety lending earthy, piney notes. I like using varieties such as East Kent Goldings, Cascade and Centennial for certain styles of stout.

A wide range of yeast strains are used for stout fermentation. Dry stouts typically are fermented using a strain that ferments dry. Highly attenuative yeast can also be used for sweet stouts because the carbohydrates lending sweetness are typically unfermentable. Some stouts contain perceptible levels of diacetyl and this aroma note is mainly due to yeast strain and fermentation method. If you like diacetyl in your stout, choose an appropriate yeast strain and minimize warm conditioning following fermentation. Surprisingly, many commercially available stouts are fermented with lager yeast. Many of the licensed Guinness breweries use their lager strains for stout. Dragon Stout from Jamaica and Kirin Stout from Japan also use lager yeast.

So, whether you’re brewing a dry Irish, American microbrew-style or imperial stout, you’ve got many brewing options to consider.

Dry Irish Stout
(5 gallons/19 L, all-grain)
OG = 1.040  FG = 1.008
IBU = 35  SRM = ~38  ABV = 4.1%

Ingredients

7.5 lbs. (3.4 kg) 2-row pale malt (preferably Maris Otter)
12 oz. (0.34 kg) roasted barley (400–500 °L)
2.0 oz. (57 kg) chocolate malt (300–400 °L)
1/2 tsp. baking soda (added to mash)
1 tsp. Irish moss
9.25 AAU Perle hops (bittering) (1.2 oz./33 g of 8% alpha acid)
Wyeast 1084 or White Labs WLP004
3/4 cup corn sugar (for bottling)

Step by Step

Bring 9 quarts (9 L) of water to 166 °F  (74 °C) and mix in the malts and baking soda. The temperature should fall between 154–156 °F (68–69 °C). Hold mash for 60 minutes before sparging. Recirculate the wort until clear and then run off wort to the kettle. Once the top of the grain bed is covered by an inch of wort, begin sparging with 176 °F (80 °C) water. Collect 6 gallons (23 L) of wort. Bring wort to a boil, add hops and boil for 60 minutes. Add Irish moss 5 minutes before the end of boil. Cool wort to 70 °F (21 °C), aerate, pitch yeast and ferment at 70 °F (21 °C). Rack after 10 days and a second time in another 14 days. Then prime, bottle and hold 7 days before drinking.

This is the classic stout to serve on mixed gas using a stout faucet. If this method is desired, skip the priming and bottling step and use the technique detailed on page 33.

Extract with grains option: An extract version of this beer can be made by substituting the pale malt for 6.0 lbs. (2.7 kg) of light liquid malt extract or 4.25 lbs. (1.9 kg) of light dry malt extract.

Microbrew-Style Stout
(5 gallons/19L, extract w/grains)
OG = 1.080  FG = 1.016
IBU = 70  SRM = 75  ABV = 8.3%

Ingredients

3.33 lbs. (1.5 kg) Breiss Light dried malt extract
6.0 lbs. (2.7 kg) Coopers Light liquid malt extract
8.0 oz. (0.23 kg) dark crystal malt (130–150 °L)
6.0 oz. (0.17 kg) medium crystal malt (45–55 °L)
6.0 oz. (0.17 kg) roasted barley (400–500 °L)
6.0 oz. (0.17 kg) chocolate malt (300–400 °L)
16 oz. (0.45 kg) Weyermann Carafa III
dehusked roasted malt (450–500 °L)
1 tsp. Irish moss
18.3 AAU Nugget hops (60 min) (1.5 oz./yy g of 15% alpha acid)
6 AAU Cascade hops (20 min) (1 oz./28 g of 6% alpha acid)
8 AAU Centennial hops (5 min) (1 oz./28 g of 8% alpha acid)
Wyeast 1056 or White Labs WLP001
3/4 cup corn sugar (for bottling)

Step by Step

Place crushed grains in a nylon steeping bag and heat 105 fl. oz. (3.1 L) of water to 162 °F (72 °F). Steep grains in this water for 45 minutes. The temperature should be around 150 °F (66 °C) for the duration of the steep.

Combine 1.7 gallons (6.4 L) of water and dried malt extract (DME) with “grain tea“ and heat to a boil. (To save time, heat water and DME while steeping the grains.) Boil wort for 60 minutes, adding Nugget hops at the beginning of the boil. With 20 minutes left in the boil, add the Cascade hops. With 15 minutes left, stir in the liquid malt extract (LME) and add Irish moss. Stir in LME thoroughly to prevent extract from sinking in kettle and scorching to the bottom. Add Centennial with hops with 5 minutes left in the boil.

After boil, cool wort down to 70 °F (21 °C), aerate, pitch yeast and ferment at 70 °F (21 °C). Rack after about 14 days and a second time in another 21 days. Then prime, bottle and hold for at least 14 days before drinking. This beer can be consumed young or can be laid down for aging.

All grain option: An all-grain version of this beer can be made by substituting 14.25 lbs. (6.5 L) of 2-row pale malt for the liquid and dried malt extracts.

Murphy’s Stout clone
(5 gallons/19 L, extract w/ grains)
OG = 1.038  FG = 1.007
IBU = 36  SRM = 41  ABV = 4.0%

Ingredients

2.66 lbs. (1.2 kg) Muntons Light liquid malt extract (LME)
0.66 lbs. (0.3 kg) Muntons Light dried malt extract (DME)
1.0 lb. (0.45 kg) 2-row pale ale malt.
2.0 oz.  (57 g) crystal malt (90 °L)
3.0 oz.  (85 g) chocolate malt
10 oz. (0.28 kg) roasted barley (500 °L)
12 oz. (0.34 kg) cane sugar
9.33 AAU Willamette hops (60 mins)
(1.9 oz./53 g of 5% alpha acids)
0.25 oz. (7.1 g) East Kent Goldings (EKG) hops (15 mins)
White Labs WLP005 (Dry English Ale) yeast (1 qt./1 L yeast starter)
2/3 cup corn sugar (for priming)

Step by Step

Steep all crushed grains at 150 °F (66 °C) in 1.35 gallons (5.1 L) of water for 45 minutes. Add 1.2 gallons (4.5 L) of water and DME to “grain tea” and bring to a boil. Add Willamette hops and boil for 60 minutes. Add LME, sugar and EKG hops for final 15 minutes of the boil. Cool wort, siphon to fermenter, aerate and pitch yeast. Ferment at 70 °F (21 °C). Bottle with corn sugar.

All-grain option

Replace first three ingredients with 5 lbs. 12 oz. (2.6 kg) 2-row pale ale malt. (Option: Treat water with CaCO3 to reach 150 ppm CO32+.) Combine pale and crystal malt with 2.1 gallons (8.0 L) of water at 161 °F (71 °C). Stir dark grains into the top half of the grain bed and the mash should settle in to a temperature of 150 °F (66 °C). Mash for 60 minutes. Boil 90 minutes, adding hops at times indicated in the recipe. Add sugar for final 15 minutes of boil. Ferment at 70 °F (21 °C). Keg (and perhaps push with nitrogen) or bottle.

Guinness Foreign Extra Stout clone
(5 gallons/19 L, all-grain)
OG = 1.078  FG = 1.019
IBU = 40  SRM = 43  ABV = 7.5%

Ingredients

13 lbs. (5.9 kg) 2-row pale ale malt
2 lbs. 2 oz. (0.96 kg) flaked barley
1.0 lb. (0.45 kg) roasted barley (500 °L)
11.33 AAU Challenger hops  (60 mins)
(1.6 oz./46 g of 7% alpha acids)
Wyeast 1084 (Irish Ale) or White Labs WLP004 (Irish Ale) yeast
(2 qt./2 L starter plus 0.5 qt/500 mL mini-starter)
2/3 cup corn sugar (for priming)

Step by Step

Brew pale base beer  Mash flaked barley and 11 lbs. (5.0 kg) of pale malt for 60 minutes at 152 °F (67 °C) in 4.1 gallons (15 L) of water. Collect about 6 gallons (23 L) of wort and boil hard for 90 minutes, adding hops with 60 minutes left in boil. Shoot for a yield around 4 gallons (15 L). (Your SG should be around 1.093.) Cool wort, siphon to fermenter, aerate and pitch yeast from big starter. Ferment at 68 °F (20 °C).

Make stout coloring extract Mash  roasted barley and 2.0 lbs. (0.91 kg) of pale malt at 152 °F (67 °C) in 80 oz. (2.4 L) of water. Stir in CaCO3 until pH value is between 5.2 and 5.4. Mash for 45–60 minutes. Collect 1.5 gallons (5.7 L) of wort. Boil for 30 minutes to reduce volume to 1 gallon (3.8 L). Cool wort, siphon to 1 gallon (3.8 L) jug, aerate and pitch yeast. Ferment at 68–72 °F (20–22 °C).  Make stout  Combine beers in keg or bottling bucket.      — Chris Colby