Smoked beers tend to elicit strong reactions from beer drinkers. The first time most people try one, they either say, “It tastes like a campfire. Yuck” or, “It tastes like a campfire — awesome!” The first smoked beer I ever had was an Aecht Schlenkerla Rauchbier Märzen. I was in graduate school, relaxing at a bar with some friends. The place had a huge beer list and I was determined to try at least one new beer every time we went there. I remember being blown away by the almost bacon-like smoke character in the beer. I had just started brewing not long before, so one of my friends asked, “How did they do that?” At that point, I had no idea. None of my homebrew books mentioned smoked beers. At that time, I guessed that the brewers either stored the beer in wooden barrels or bubbled smoke through it.
As it turns out, I was way off. Brewing a smoked beer requires no special steps or equipment, just a special ingredient — smoked malt. Smoked malt is simply malt that has been dried in the presence of smoke. There are commercially-produced smoked malts and you can also smoke your own malt at home.
You can make a smoked version of any beer you like, but commercial examples come from a few select styles. Two breweries in Bamberg, Germany — Schlenkerla and Spezial — have produced smoked German lagers and ales for centuries. These include Märzens, bocks, doppelbocks and weizenbocks. American microbreweries have also experimented with smoked beers, with porter being the most commonly smoked style. Although smoked beers are relatively uncommon, smoked foods are not and we can learn much from examining them.
Smoke and Food
Smoke has many component molecules, and its interaction with food has been extensively studied. Common smoked foods include fish (especially salmon), ham and bacon, sausages, cheeses, chipotle (smoked jalapeño) peppers and many others — including, of course, smoked malt used in the brewing of smoked beers and in the production of whiskey.
Smoke contains a variety of compounds that retard spoilage, including formaldehyde, acetic acid (the acid in vinegar) and various phenolic compounds. Some of these phenolics also have anti-oxidant properties. The anti-oxidant properties of smoke were a big reason it was used on fish before refrigeration. The anti-oxidants kept the fats and oils on the surface of the fish from going rancid. (Rancidification is the decomposition of fats or oils.) This — usually in combination with salting or drying — allowed fish to be stored for weeks. The pH of smoke is also very low, usually under 2.5, which makes it hostile to microorganisms.
These days, food is smoked primarily for the flavor contribution of the smoke. When wood is burned, smoke can smell of caramel, bread, fruits, flowers, vanilla, clove and many other things. It also, of course, has a smoky pungency to it. The character of the smoke depends largely on what kind of wood is being burned and under what conditions. Many of the phenolic compounds in smoke are quite reactive and thus smoke flavors can diminish in foods, sometimes in a matter of weeks.
For all the wonderful properties of smoke, it does have the potential to cause health problems. Burning wood gives off polycyclic aromatic hydrocarbons (or PAHs). Many of these compounds have been found to be carcinogenic. Commercially produced smoked malt is made under conditions to minimize PAH content and in the sidebar on smoking malt, I’ll explain how to reduce your risk. PAHs are found in many foods — most especially foods grilled over wood — and you can never completely eliminate your exposure to them.
What’s in Wood
Wood is composed of three major materials, cellulose, hemicellulose and lignin. Cellulose is a linear chain of glucose molecules, similar to starch, but bonded together in such a way as to be indigestible by animals. (Termites can digest the cellulose in wood due to bacteria in their guts that can degrade cellulose.) A typical chain of cellulose contains 7,000 to 15,000 sugar subunits.
Hemicellulose is similar to cellulose, but is composed of many different types of sugars beside glucose. These include xylose, and lesser amounts of mannose, galactose and arabinose. Hemicellulose usually contains around 200 sugar subunits in a branching configuration.
When cellulose or hemicellulose is burned, it gives off many compounds, including furans (which smell sweet, bready and floral), lactones (which smell like coconut or peach) acetaldehyde (green apple), acetic acid (vinegar) and diacetyl (buttery).
Lignin is a class of molecule composed of many rings of carbon atoms. The more lignin in wood, the hotter it burns. The phenolics in smoke come from the decomposition of lignin. These include guaiacol (which smells smoky or spicy), vanillin (the main aromatic compound in vanilla), phenol (pungent), isoeugenol (sweet or clove-like) and syringol (spicy, sausage-like).
One of the minor components of wood is protein, so smoke can also contain Maillard products, those “browning products” formed by the interaction of sugar and amino acids under heat. If you are an advanced homebrewer, you probably recognized many of the compounds mentioned above. If not, though, don’t worry, the point is that smoke contains a large number of molecules that can confer flavors or aromas to smoked malt.
If you’re going to brew a smoked beer at home, you first need to find a source of smoked malt. There are two commonly-available commercial smoked malts available to North American homebrewers , Weyermann rauchmalz (smoked malt) and peat-smoked malt. Peated malt is available from maltsters Hugh Baird, Thomas Fawcett and Simpsons.
Weyermann rauchmalz is a pale, base malt (1.7–2.8 °L), smoked over beechwood. Beech is native to Europe and North America and is used frequently as firewood because it burns steadily and cleanly. (Beech is also the wood that Anheuser-Busch uses to age Budweiser on. In their conditioning tanks, it serves as a place for the yeast to settle.) Rauchmalz has a fairly mild smoke character and can be used for up to 100% of the grist.
Peat-smoked malts are also light in color — generally 2–3 °L — but have a much more intense smoke character. Peat is partially-decomposed organic matter (mostly mosses and lichens) that forms in acidic wetlands called bogs. In many countries, it is dried and burned as fuel and its smoke has a very distinctive aroma. For awhile in North American homebrewing, it was practically de rigueur to add peat-smoked malt to Scottish-style ales. These days, the pendulum has swung the other way and this practice is avoided as it never was a traditional commercial practice.
Some maltsters make peat-smoked malt with different levels of smoke character. In general, peat-smoked malt should be used in very small quantities, perhaps up to 5% maximum for the lightly-peated versions. The primary customer for peat-smoked malts is distilleries.
The big question many homebrewers will have is, of course, how much smoked malt to add when brewing a smoked beer. As it turns out, it’s hard to give a firm answer. For one thing, the strength of smoked malt varies. Even if the maltster imparted exactly the same amount of smoke character to each batch — which is doubtful — smokiness declines over time. And, when using home-smoked malt, your results can vary wildly. If you were brewing a series of smoked beers, you could easily use the first as a gauge of the intensity of the smoke in the malt. However, for most homebrewers, their smoked beer is going to be a standalone brew. So, with that in mind, here is a rough guideline for smoked malt additions.
When brewing with peat-smoked malt, restraint is the watchword. With this malt, it is unlikely that you would ever want to exceed 5% of the total grist. In fact, unless you really like gobs of smoke, with a pungent “peaty” character, you’d be better off keeping this to 1% or below.
When brewing with the milder rauchmalz, even a small amount will give a hint of smoke. Using from 1 to 5% rauchmalz will yield a beer with smoky highlights that accentuate the other flavors in the beer. At around 25% rauchmalz, the beer will have a definite smoky character that stands out, but doesn’t dominate the beer’s flavor and aroma. This is a nice level for smoked porters, if you want both the smoke and dark grains to be on near equal footing. At around 50% rauchmalz, you will have a distinctively smoky beer. The smoke will not completely overpower the other flavors in the beer, but it will be the dominant one. At this level, the smoke intensity will be similar to that of the beers produced by Schlenkerla Brewery. From there, you can scale the smoke malt all the way to 100% of the grist. I’ve made beers with around 98% rauchmalz (and just a little CaraMunich®) and they have been smoky, but not over-the-top for a smoked beer lover.
When brewing a smoked beer, you need to ensure that you eliminate any form of chlorine from your brewing liquor. Otherwise, the phenols in smoke will react with the chlorine (including chloramines) and produce off flavors. One sure way to eliminate all forms of chlorine in your brewing water is to treat it with a potassium metabisulfite. To do this, add one Campden tablet — available at any home winemaking shop — to every 20 gallons (76 L) of water and let it sit overnight, loosely covered. The Campden tablet will dissolve and produce SO2 gas that will react with the chlorine, neutralizing it. This will happen very quickly. The overnight stand is simply to let the gas diffuse out of the water. (If you’re pressed for time, you can skip that last part.)
Smoked beers can have a moderate amount of hop bitterness, but smoke seems to clash with hop flavor or aroma. Most smoked beer recipes are either malt-focused or get all their hop character from an early addition of hops. On the other hand, you might find a combination of wood, hop variety and other ingredients that mesh well. Feel free to experiment, if you know the risks.
Yeast and Fermentation
Every commercial smoked beer I’ve ever tasted has been made with a “clean” strain of yeast. Lager yeasts for the Märzen-style beers and ale yeasts with a restrained amount of fruitiness for the porters and other ales. To preserve as much of the smoke character as possible, it would be wise to ferment the beer at the low end of the recommended temperature range. Be sure to pitch an adequate amount of yeast, however. There are smoked wheat beers, and the clove-like aspects of a German hefe-weizen strain could mix well with the smoke — and, if you’re feeling adventurous, maybe a smoked Belgian? The possibilities are only limited to what you can think up sitting around the campfire.
Smoke on the Lager
(5 gallons/19 L, all-grain)
OG = 1.057 FG = 1.014
IBU = 30 SRM = 14 ABV = 5.5%
9.5 lbs. (4.3 kg) Weyermann rauchmalz
2.0 lbs. (0.91 kg) Weyermann Munich
Type I malt (~6 °L)
0.5 lbs. (0.23 kg) Weyermann
CaraMunich® III malt (~60 °L)
8 AAU Magnum hops (60 mins)
(0.57 oz./16 g of 14% alpha acids)
Wyeast 2206 (Bavarian Lager) or
White Labs WLP820
(3 qts./3 L yeast starter)
Step by Step
Ferment yeast starter at room temperature, then transfer to lagering fridge at beginning of brewday. Treat brewing water with one Campden tablet the night before brewday. For wort production, use a single decoction mash. In your kettle, mash in to 131 °F (55 °C) with 17 qts. (16 L) of water. Pull first decoction, roughly the thickest one-third of the mash, and place it in a large kitchen pot. Heat decoction to 158 °F (70 °C) and hold for 5 minutes, then bring decoction to a boil. Boil decoction for 20 minutes, stirring constantly. Return decoction to main mash and add heat, if needed, to bring temperature to 152 °F (67 °C). Hold for 45 minutes. Heat mash to 168 °F (76 °C), then transfer to lauter tun. (Try to minimize any splashing when you transfer it from the kettle to lauter tun.) Let grain bed set up for 5 minutes before you begin recirculating and running off the wort. Keep sparge water heated so that the top of grain bed remains at 165–168 °F (74–76 °C) while you collect your wort. Collect 6.5 gallons (25 L) and boil for 90 minutes, expecting to yield 5.0 gallons (19 L) of wort after boil. Cool wort to 54 °F (12 °C) and transfer to fermenter. Aerate well, pitch chilled yeast from starter and let ferment at 54 °F (12 °C) until rate of fermentation slows greatly (usually after 10–14 days). Let temperature rise to 60 °F (16 °C) to finish off fermentation. Lager beer for 4–6 weeks, then keg.