Brewing Modern Porter
If there’s a brewing question more ubiquitous than “what’s the difference between stout and porter?” I don’t know what it is. One thing I do know, though, is that like most any discussion of beer styles the questions shouldn’t be isolated to how one style compares to another, but how those styles have evolved over time. In a beer and brewing world that places a premium on innovation and novelty it might seem like an odd question; some might argue that beer styles as we’ve traditionally understood them don’t even exist anymore. No matter how quickly things change, though, it’s nearly always possible to see the past informing the present, and see patterns emerging in a present that seems too chaotic to define.
It’s in that spirit that we look, today, at what porter has grown into, examine the conventional modern varieties (American/robust porter, English porter, and Baltic porter), and discuss approaches to brewing porter that will enable you to leverage the classic elements of the style to create your own modern take on it.
What is a Porter?
Historically, porter was generally a descriptor for a dark beer on offer from a brewery, with “stout” being an internal (brewery-specific) differentiator of relative strength. “Stout” porters were generally stronger, on average, than “simply” or “standard” porters, but even between breweries these designators could vary and there was no systemic differentiation. In today’s beer world, any meaningful differentiation between stout and porter as broad category designations is patently invisible; we have to dig down into a sub-style to distinguish each from its stylistic cousins. Porters (and stouts, for that matter) see significant variation in body, ABV, fermentation class (ale vs. lager), and ingredient emphasis. There is one place where a distinction might exist, though: Roast character.
As a category, modern porters — and here I’m drawing on the 2015 Beer Judge Certification Program (BJCP) and 2020 Brewers Association (BA) style guides — are characterized by clear but restrained roast/dark malt flavors, a moderate level of perceived bitterness, and noticeable esters. The brown and Baltic porters are described as “smooth,” “moderate,” and “restrained” in their roast character, even when that flavor is relatively high in magnitude. Even the American (robust) porter, which comes closest to embracing a more aggressive “roasty” profile, notes that it should not be “overly acrid,” suggesting a strong roast intensity and can feature “a bit of grainy, dark malt dryness in the finish.” Style guidelines also acknowledge that porters — owing in part to this aforementioned restraint — serve as a great base for a variety of creative modern interpretations, including smoked porter and (ironically) a resurrected molasses-and-treacle-and-licorice-laced pre-Prohibition porter.
Porter is a survivor as a style thanks to its flexibility and approachability, and the wide range of ingredients. Processes available to 21st century homebrewers mean that it can be tuned to the next century as easily as it has been to prior eras. The sub-categories described in the BJCP and BA style guidelines are a good starting point for your brewing, incorporating the lessons learned from craft brewers up to the present day, while still leaving room for new interpretations and adaptations.
Recipe Considerations
There are a number of recipe considerations when designing a porter recipe, most aimed at developing dark malt flavors without yielding a beer that is too overtly “roasty.” Hops and yeast selections will also come into play, however, and a blinkered focus on the grist will leave a number of useful tools unused! We’ll be starting with a set of good “baseline” recommendations for porter recipes, and then add in some of the choices you might want to consider when moving beyond porter’s historical roots.
Grains
It’s a good idea to set yourself some guard rails in the grist. By shifting paler grains up the Lovibond scale we add a “richer” caramel character — say, 80 °Lovibond v. 40 °Lovibond crystal to add more toffee flavors — we can deemphasize roasted flavors by balancing them. At the same time, using chocolate rye adds mild cocoa dark malt flavor, but without the burnt husk and sharper roast intensity one would get from a chocolate barley malt. Likewise, specialty malts like Caramunich and Briess Special and Extra Special Roast will emphasize “dark” but not “intensely roasty” flavors, like prune, campfire, and dark treacle.
Yeast
Yeast choice plays a significant role as well. A classic “clean” ale yeast can work, but as an added buffer against an over-roasty beer an English ale yeast is worth considering: The bit of diacetyl production is both less-noticeable in presentation in a darker beer and a counterbalance against sharp roast flavors, and the berry esters add a nice complementary background flavor. Ryan Diehl of Imprint Beer Co. in Hatfield, Pennsylvania leans on Wyeast 1968 (London ESB) yeast in several of their innovative dark beers including their Imperial Milk Stout (brew it yourself with the recipe below). Brett Willis at Allagash Brewing Company in Portland, Maine notes that they’re never shy about taking advantage of the eccentricities of Belgian strains in their stouts and porters: “The Belgian Abbey-style yeast strain we use gives the beer some light hints of dried fruit, mingling with all of the roasty notes. Though it has a lightly sweet-perceiving note, it’s a dry one for sure.” Although we tend to think in terms of malt character in porter, yeast has a role to play.
Hops
There are two considerations when it comes to hops: Bittering and flavor. Overall, don’t go overboard on IBUs. This is a place where you’ll want to err on the lower side of the noted IBU range for a given style and let the gravity points have a bit of additional advantage in the Bittering Unit/Gravity Unit ratio. A low-cohumulone hop variety may also be worth considering to eliminate a risk of sharper bittering character (if you believe in that sort of thing). From a flavor perspective, think Continental, even in American or English porter interpretations. The floral, herbal, and peppery notes of a Tettnanger or Hallertauer variety is often a good fit for the restrained and courteous porter style, as are the earthy, woodsy flavors of English hops. This will be all the more true as we start getting creative with elaborations on the established style sub-categories and play with gravity, smoke, and other special ingredients and flavors.
The preceding may be unfairly interpreted as an attempt to get you to make your porters boring, but nothing could be further from the truth. Porter recipes are best set up with a more subtle and balanced profile, but that should in no way nudge you in the direction of a Schwarzbier or a Continental dark lager. Complexity and amplitude are not necessarily linked: Your porter can (and should) be both interesting and restrained.
Water
In what may now seem like a broken record, we should target a balanced water profile that is neither flintily hard nor vacantly soft, and since we’re working with a lot of dark malts (which can drive acidity in the mash) a relatively high level of alkalinity is appropriate to adequately buffer the mash. Finding the appropriate balance point in your water chemistry is going to be a matter of personal adjustment. Julian Shrago, Owner and Brewmaster at Beachwood BBQ and Brewing in Long Beach, California, says they “treat water with chalk to increase residual alkalinity,” while Ryan Diehl at Imprint adds calcium chloride. Treat your water “away” from either end of the spectrum for best results. A good middle-of-the-road water profile is a good starting point.
Process Considerations
That restraint and awareness of its limitations follows porter into our discussion of brewing process. Water chemistry adjustment, mashing, and fermentation temperatures all play an important role.
Most brewers will tell you that a slightly warmer saccharification step in the mash is a good idea. In much the same way we can consider using richer-flavored crystal malts and less-austere yeast strains as tools to balance out any harsh flavors, a single-infusion mash in the 153–154 °F (67–68 °C) range will result in a slightly less-fermentable wort, giving a cushier backdrop to our traditional or innovative flavors. It’s a subtle difference, but a prospectively valuable one, especially if your maltster has misjudged the roast level on your grist and you end up with sharp flavors to balance. Selecting base malts with a less aggressive enzyme package, specifically malts in the 3–5 °L range as opposed to the 1.5–2.5 °L range, also helps; especially when coupled with hotter mashes.
Finally, just as we go a bit warm in the mash, we can aim a bit low in the fermenter. Treat your yeast on the cooler side of its stated optimum range. There are two reasons for this approach. First, with all of our efforts to guard against an overly sharp roast profile, we can end up with a beer that is all roundness and no edge. Since we’ve already selected a yeast strain that produces some balancing flavors, there’s no harm in keeping it on a shorter leash; it’s easier, in my experience, to use a more-complex yeast and get a bit of flavor out of it with a cool fermentation than a simpler yeast and whip some flavor from it through a warmer fermentation. Second, this method works because we’re not as concerned about getting a bone-dry finish in the beer — in fact, it would probably be a detriment. So low and slow is the name of the game on fermentation temperature.
These are relatively subtle considerations, though, by comparison to the technical feats required from some style families. Trust your recipe, and you can mostly follow your standard process!
Getting Creative
“Modern” isn’t synonymous with “outlandish,” of course — the porter styles described by the BA and BJCP are modern beers that are descended from centuries-older iterations — but it’s also true that porter serves as an outstanding backdrop for creative variations.
First, let’s talk gravity. While the range of ABV for the different porter styles is pretty broad, ranging from about four percent for English porter to just under ten percent for Baltic porter, there’s still room there at the higher end of the spectrum to have some fun. Perhaps the best advantage in the creation of imperial-strength porters is that in a style where you’re looking for restrained roastiness, more body and more alcohol-derived sweetness is anything but a challenge. In fact, it means that higher original gravity is itself a natural bulwark against an overly-roasty beer that might be more properly considered a stout. Imperial porter (such as Imprint’s Imperial Milk Porter) is also a more amenable base recipe than imperial stout for the addition of specialty ingredients like coffee, maple, coconut, and more since the ingredients have a cleaner background against which to be perceived. They also hold up just as well to barrel aging, if that’s your thing.
Another perfect marriage is porter and smoke — if anyone has doubts, I defy you to crack open a bottle of Alaskan Brewing Company Smoked Porter and argue that roast and smoke are not a perfect combination. You’re welcome. The slightly sweet flavor that smoke adds to a beer is a perfect fit for porter, and in an age when we have access to a range of smoked malts (including artisanal varieties that utilize a greater range of woods, each imparting unique flavors), the beers are far from repetitive in the way that hop-driven beers often are. Beachwood’s “Wholly Smoke” uses three distinct smoked malts to achieve its noted complex-but-drinkable profile (check out the clone recipe below). Once upon a time all porter was smoked porter (vis a vis brown malt), and it’s nice when history comes pleasantly full-circle.
Fruits, spices, and herbs add to porter just as they do to many beer styles, with one additional benefit: Porter as a style is robust enough to bear up against fruits and spices that often blow away lighter styles. Raspberry, tamarind, cinnamon, basil, fenugreek, white pepper, blood orange — all can be used liberally in a porter without running into a blank slate (like a low-gravity pale ale) or a beer that is itself strongly flavored and competing with them (like many stout varieties).
To make a long story short, there’s not much that you can’t do with a modern porter.
A Relevant Style
In an era where everything seems to be hoppy, juicy, and light, it’s something of a relief to see so many porters on the market. Far from being a seasonal beer or a relic of a stodgy North Sea brewing legacy, porter remains an integral part of the beer and brewing world. Its flexibility, its character, and even its restraint ensures that it will remain so for a long time to come.
Imprint Beer Co.’s Imperial Milk Porter clone
(5 gallons/19 L, all-grain)
OG = 1.102 FG = 1.026
IBU = 30 SRM = 60 ABV = 11.4%
Ingredients
12 lbs. (5.4 kg) American 2-row pale malt
2.5 lbs. (1.1 kg) malted oats
2.5 lbs. (1.1 kg) Weyermann Caramunich® III malt
12 oz. (0.34 kg) chocolate malt
12 oz. (0.34 kg) Briess Midnight Wheat malt
8 oz. (0.23 kg) roasted barley
1 lb. (0.45 kg) lactose
8 AAU Magnum hops (60 min.) (0.5 oz./14 g at 16% alpha acids)
Wyeast 1968 (London ESB), White Labs WLP002 (English Ale), or LalBrew London English-Style Ale yeast
2⁄3 cup corn sugar (if priming)
Step by step
Mill the grains and mix with 6 gallons (23 L) of 165 °F (74 °C) strike water to reach a mash temperature of 152 °F (67 °C). Hold this temperature for 60 minutes. Vorlauf until your runnings are clear. Sparge the grains with enough water to collect 7 gallons (26.5 L) of wort, add lactose and stir to dissolve. At this point, check the gravity of the wort in the kettle. With that volume, the SG should be 1.073. Add sugar or dried malt extract if your gravity is too low. Boil for 120 minutes, adding hops according to the ingredient list.
After the boil, turn off heat and chill the wort to slightly below fermentation temperature, about 65 °F (18 °C). Aerate the wort with pure oxygen or filtered air and pitch yeast.
Ferment at 66 °F (19 °C) for 10 days, then raise the temperature to 70 °F (21 °C) for 3–4 days. Upon completion of fermentation (check your gravity — being such a “big” beer this may take longer than expected), crash the beer to 35 °F (2 °C) for 48 hours, and bottle or keg the beer and carbonate to approximately 2.25 volumes.
Imprint Beer Co.’s Imperial Milk Porter clone
(5 gallons/19 L, partial mash)
OG = 1.102 FG = 1.026
IBU = 30 SRM = 59 ABV = 11.4%
Ingredients
8 lbs. (3.6 kg) pale liquid malt extract
2.5 lbs. (1.1 kg) malted oats
2.5 lbs. (1.1 kg) Weyermann Caramunich® III malt
12 oz. (0.34 kg) chocolate malt
12 oz. (0.34 kg) Briess Midnight Wheat malt
8 oz. (0.23 kg) roasted barley
1 lb. (0.45 kg) lactose
8 AAU Magnum hops (60 min.) (0.5 oz./14 g at 16% alpha acids)
Wyeast 1968 (London ESB), White Labs WLP002 (English Ale), or LalBrew London English-Style Ale yeast
2⁄3 cup corn sugar (if priming)
Step by step
Pulverize the malted oats as best you can. The more starch you can expose, the faster conversion will take place. Bring 1 gallon (3.8 L) of water to approximately 162 °F (72 °C) and hold there. Steep the malted oats in a fine mesh grain bags for 60 minutes. Begin heating another 1 gallon (3.8 L) to 170 °F (77 °C). Add the remaining crushed specialty grains to another grain bag. Mix both water and specialty grains in with the mashing oats. Steep an additional 15 minutes. Remove the grain bags, placing them in a colander and slowly rinse them with 2 gallons (7.6 L) of hot water. Add liquid extract and lactose while stirring, and stir until completely dissolved. Top up as necessary to obtain 6 gallons (23 L) of wort. Boil for 60 minutes, adding hops according to the ingredient list.
After the boil, turn off heat and chill the wort to slightly below fermentation temperature, about 65 °F (18 °C). Aerate the wort with pure oxygen or filtered air and pitch yeast.
Ferment at 66 °F (19 °C) for 10 days, then raise the temperature to 70 °F (21 °C) for 3–4 days. Upon completion of fermentation (check your gravity — being such a “big” beer this may take longer than expected), crash the beer to 35 °F (2 °C) for 48 hours, and bottle or keg the beer and carbonate to approximately 2.25 volumes.
Tips for success:
Imprint Brewer and Co-Founder Ryan Diehl notes that in the interest of palate “mellowness,” you should target about 200 ppm of chloride, adjusting as necessary with calcium chloride. Between the water chemistry and the use of lactose, this recipe allows for a chocolate-forward expression without being overly roasty. Ryan also says that this recipe sells well on its own, but also serves as a fantastic base for their coconut porter, maple porter, and coffee porters. If pursuing those options, he advises leaving out the lactose.
Beachwood Brewing Co.’s Wholly Smoke Robust Smoked Porter clone
(5 gallons/19 L, all-grain)
OG = 1.071 FG = 1.016
IBU = 36 SRM = 48 ABV = 7.2%
Wholly Smoke incorporates a blend of smoked malts to create a rich and complex smoky robust porter. Due to the high percentage of smoked malts this beer is not easily replicated using malt extract.
Ingredients
4.8 lbs. (2.2 kg) Weyermann rauchmalt
4.5 lbs. (2 kg) Maris Otter pale ale malt
1.25 lbs. (0.57 kg) Briess cherrywood smoked malt
1 lb. (0.45 kg) Weyermann oak smoked wheat malt
1 lb. (0.45 kg) crystal malt (45 °L)
1 lb. (0.45 kg) crystal malt (77 or 80 °L)
12 oz. (0.34 kg) chocolate malt
12 oz. (0.34 kg) black patent malt
8 AAU Magnum hops (60 min.) (0.5 oz./14 g at 16% alpha acids)
2.5 AAU East Kent Golding hops (20 min.) (0.5 oz./14 g at 5% alpha acids)
White Labs WLP001 (California Ale), Wyeast 1056 (American Ale), or SafAle US-05 yeast
2⁄3 cup corn sugar (if priming)
Step by step
Mill the grains and mix with 4.4 gallons (16.6 L) of 165 °F (74 °C) strike water to reach a mash temperature of 153 °F (67 °C). Hold this temperature for 60 minutes. Vorlauf until your runnings are clear. Sparge the grains with 2.9 gallons (10.9 L) and top up as necessary to obtain 6 gallons (23 L) of wort. Boil for 90 minutes, adding hops according to the ingredient list.
After the boil, turn off heat and chill the wort to slightly below fermentation temperature, about 65 °F (18 °C). Aerate the wort with pure oxygen or filtered air and pitch yeast.
Ferment at 67 °F (19 °C) for 10 days, then raise the temperature to 70 °F (21 °C) for 3–4 days. Crash the beer to 35 °F (2 °C) for 48 hours and then bottle or keg the beer and carbonate to approximately 2.25 volumes.
Tips for success:
Owner and Brewmaster Julian Shrago notes that this beer is the very definition of a “modern” porter, as it owes its signature flavor to cherrywood smoked malt, a product that was largely unavailable ten years ago. Owing to the high proportion of smoked base malt in this beer, extract versions aren’t advisable, but for those who are all-grain brewers there’s not much to get you into trouble here! The grist is doing most of the hard work, and your additions and fermentation are pretty straightforward.
If you find that the mild roast complexity is getting lost in the smoky background, consider replacing half of the black patent and chocolate malt with the equivalent amount of pale chocolate — you’ll get more flavors out of the more lightly-kilned chocolate malt.
