Brewing Sweet Stout with Lactose
Unlike many beer styles sweet stout has a quite specific origin, and for the better part of the 20th century only one version from one English brewer almost completely dominated the market for this type of beer. That beer, Mackeson Stout, although still around, declined in popularity and the style might have disappeared completely, as did porter in Britain at one time. But, then of course, along came American craft brewers with their desire to give new life to old established styles and to take them to extremes (as with double IPAs, imperial stouts and so on). With so few commercial versions available to them, many of these brewers brewed sweet stout in just the way they thought it should be, paying no attention of brewing to a formal style. So as a modern beer sweet stout is quite an elusive style, I can talk about it in this column without worrying about style guidelines too much.
But first a little history. Milk stout, as it was then known, was first brewed in 1907 by Mackeson’s Brewery in Kent, England. The name, of course, came from the fact that lactose is a sugar derived from milk. Since this sugar is not fermented by yeast this is something of a sweet brew (but see later under the discussion of the effect of lactose on beer’s flavor). So it seems to be an oddity that this brew originated in Kent, the great English hop growing county. But brewers at the time were in the habit of pushing their beers as being healthful and even as a good tonic for whatever might ail the drinker. Stouts in particular were being pushed as “good for you,” so one based on “milk” fitted nicely into that scenario. In fact, if I remember correctly, Mackeson used the milk connection to promote the beer as suitable for nursing mothers.
Mackeson’s Brewery passed through the hands of a couple of small breweries before being bought out by Whitbread in 1925. This company soon promoted it on a national basis, and although other brewers produced their own version of milk stout, Whitbread pretty much pushed them all to being niche beers. In fact, Whitbread, one of England’s biggest brewers, was producing some 560,000 barrels of Mackeson by 1960, which represented somewhat above half of their total production. By that time the authorities had banned the use of the word milk in the name of these beers, on the grounds that it was misleading to consumers. After that, sweet or cream stout production fell away as British consumers moved more and more towards drinking pale beer and lagers. Whitbread too fell away and sold out its brewing interests in 2001 to Interbrew, now Anheuser-Busch InBev, who still brew Mackeson Stout on a much smaller scale.
Sweet stout has enjoyed something of a small revival in this country with versions being brewed by a number of craft brewers. Whitbread’s Mackeson was a low-alcohol beer at 3% ABV, but many of the new U.S. versions are considerably stronger. I am, in fact, drinking a version from Keegan Ales in Kingston, New York as I write this (the sort of multi-tasking I like best). It is actually contract-brewed in Stratford, Connecticut (where I live) and weighs in at 6.7% ABV, very high for the style but a very satisfying drink. Other U.S. versions are often less alcoholic, although Southern Tier Brewing Co. in Lakewood, New York brews an imperial milk stout at 9.6% ABV called Crème Brûlée. As I said, it is an elusive style!
What Makes a Sweet Stout?
I think I have made it clear that I do not want to give formal style guidelines for this beer. Nevertheless, if it is to be regarded as a beer separate from all others we have to talk about what sort of characteristics it should have. It is going to have some sweetness, but lactose is much less sweet, weight for weight, than sugars such as sucrose or glucose. In fact, I like to think of lactose as giving the beer a lot of fullness on the palate rather than just sweetness. It helps to balance the sweetness with some roast character, which is best achieved by the use of some chocolate malt at around 0.25 lb. (113 g) in 5 gallons (19 L). But many brewers prefer black malt or roasted barley to give the beer a slightly harsh note and balance the sweetness; in general, limit the amounts of these to about 11⁄2 oz. (43 g) per 5 gallons (19 L) so as not to overdo the harshness (but see the recipe on page 75 for a contradiction!). For my money, a combination of chocolate and de-bittered (de-husked) black malt works well here. As to other malts, brown malt can usefully be employed in place of chocolate, and adding in higher colored caramel malts, Victory® malt, or Special B will all give this beer a little more complexity. But you can also make a very simple version starting with only a dark malt extract and lactose. This would give you something similar to the original Mackeson Stout, but could be easily improved by using some chocolate or black malt grains and steeping them before adding to the extract.
This is not a beer about hops, and they are generally used only for bittering (although I wouldn’t discourage you from using some aroma hops through a late boil addition). And the bittering should not be overdone or it will spoil the balance of the beer. I would recommend targeting 15–35 IBU, depending on the alcohol level and the malt selection used. Go for the lower end of the range if you have used a combination of, say, black malt and roasted barley and the beer is at 3–4% ABV Stronger versions and milder malts will allow you to go to the higher end of the IBU range. Almost any variety will do, although I like lower alpha acid types such as Mt. Hood, or more traditionally East Kent Goldings.
The biggest question is how strong you are going to make the beer. I like to go for 4–5%, which still keeps it in the session range but is a little more satisfying to drink. than Mackeson at 3%. Of course, there is nothing to stop you from making your beer at, say, 6–7% ABV.
You will notice that I have talked in terms only of ABV, which is because original gravity (OG) does not have the same meaning with this type of beer as it does others.
This is because the lactose will increase the OG but its contribution to FG is the same, as it is unfermentable. It is generally added at the rate of 1–3% of the wort, so that in 5 gallons (19 L) that means 1–1.5 lbs. (0.45–0.68 kg). Now, 1 lb. in 5 gallons (0.45 kg in 19 L) is about 2.2% of total wort extract (assuming an OG of 1.045) and 1% of sugar is close to 1.004 specific gravity (SG), so 2.2% will add just under 1.009 to the beer’s OG and FG. That means that if the beer had an OG of 1.045, its fermentable OG is 1.036, so that it will finish with about 3.4–3.6% ABV If you wanted, say, 5% ABV you would need to get around 1.050 from fermen-table extract, but the OG you would measure on the finished wort would be 1.059 with 1 lb. lactose added. Do note that I have used some approximations here in order to keep things simple and clear.
As to what yeast to use, almost any of the standard British ale strains can be used, as can California Ale if you want to emphasize the sugar flavor. I prefer White Labs WLP013 (London Ale) or Wyeast 1028 (London Ale) as these give some fruitiness to the beers and help the malt flavors to come through, which I find nicely balances the palate fullness from the lactose.
Here is a sweet stout recipe I like, and another is available at https://byo.com/story3213 to show just how versatile this beer can be.
Sweet Stout I
(5 gallons/19 L, all-grain)
OG = 1.064 FG = 1.014
IBU = 25 SRM = 28 ABV = 6.8%
Ingredients
10 lbs. (4.5 kg) 2-row pale malt
0.5 lb. (0.23 kg) caramel malt (80 °L)
0.5 lb. (0.23 kg) Crisp chocolate malt
4 oz. (113 g) Briess Blackprinz® malt
1.25 lbs. (0.57 kg) lactose sugar
6.75 AAU East Kent Goldings hop pellets (90 min.)
(1.5 oz./43 g at 4.5% alpha acids)
White Labs WLP013 (London Ale) or Wyeast 1028 (London Ale) yeast
3/4 cup corn sugar (if priming)
Step by Step
Mash grains at 152–154 °F (67–68 °C) with 14 qts. (13 L) water and let rest 1 hour. Run off and sparge with hot water at 160–170 °F (71–77 °C) to collect around 6 gallons (23 L) of wort. Once at a boil, add hops and boil for 90 minutes. Turn off heat and add lactose, stirring well to dissolve. Rack from trub, cool to 65–70 °F (18–21 °C) and pitch yeast, preferably as a 1 qt. (1 L) starter. Ferment at same temperature for 5–7 days before racking to secondary. Leave for 1–3 weeks before bottling or kegging in the usual manner.
Extract with grains option:
Replace all the 2-row pale malt with 6.6 lbs. (3 kg) golden liquid malt extract (LME). Steep the crushed grains in 2 gallons (7.6 L) water at 160 °F (71 °C) for 20 minutes. Rinse with 2 qts. (2 L) hot water and top off to 6 gallons (23 L). Once at a boil, turn off the heat and stir in the LME. The remainder of this recipe is the same as the all-grain version.
Tip:
If you keg this beer and have the appropriate equipment you can serve it with mixed nitrogen/carbon dioxide gas. In any case, it is a very pleasant drink, not complex perhaps, but with enough body and hint of roast so it tastes very full and chewy but not cloyingly sweet. As an elusive style, you can consider the above recipe and the additional Sweet Stout II recipe online as merely stepping-stones to formulating your own unique sweet stout.
