Malting barley stands as a cornerstone in the production of beer, a beverage that has accompanied human civilization for millennia. While the utilization of adjuncts like sugars and various starch forms is undeniably beneficial, especially in the crafting of contemporary ales, these elements cannot supplant the indispensable role of malt. Malt, particularly when derived from barley, serves not just as a fundamental component in the making of beer, but should predominantly constitute the grist—the mixture of grains to be milled. The late Hofrath Lintner aptly termed it as “the soul of beer.”
Derived from a cereal grain, malting barley contributes significantly to the flavor, color, and texture of beer. Yet, despite its ubiquity, the technical processes underlying its transformation are intricate and deeply scientific. This narrative seeks to illuminate the multi-step, biochemical voyage that barley embarks upon to ultimately serve its role in beer production.
Barley (Hordeum vulgare) is selected as the malt of choice for many brewers due to its rich enzymatic content, the balance of protein and carbohydrate, and its robust nature to withstand varying environmental conditions. However, the raw barley grain is unsuitable for brewing. In its natural state, the starches are not readily fermentable by yeast and the complex proteins can result in a beer that is hazy or unstable. Thus, it is imperative to subject barley to a malting process, designed to manipulate the grain’s internal biochemical structures and prepare it for brewing.
The science of malting barley is a fascinating blend of biochemistry, engineering, and artistry. From the initiation of steeping to the final stages of roasting, each phase is a carefully calibrated, scientifically rigorous process aimed at converting raw barley grains into an optimized ingredient for brewing. While the specifics can be highly technical, involving precise temperature controls, enzymatic reactions, and timing, the overarching goal is clear: to create a substrate that is perfectly suited to the brewing process, while also offering the creative freedom for individual expression in the final product—beer. Thus, malting stands as both a science and an art, serving as a critical intersection between the natural world and human ingenuity.
1879 October 4th Johann Baptist Weyermann establishes the “Mich. Weyermann’s Malzkaffee Fabrik
Long before anyone started writing history, people were making malt, pretty much as we know it today. While we don’t know exactly when or how malt first came into being, there’s an old tale that says early Egyptians made it using a pretty clever method. They put the malt in a wicker basket and lowered it into an open well. This was their way of soaking the malt in water, which is the first step in turning it into what we recognize as malt.
Once it was soaked, they’d lift the basket up to let the grains start sprouting, or germinating. The interesting part is that they used the well as a kind of natural thermostat. If they wanted to slow down the sprouting because it was getting too hot, they’d lower the basket deeper into the well where it was cooler. To speed things up, they’d lift the basket higher where it was warmer.
To make sure the malt didn’t stick together, they’d pull the basket to the very top of the well and give it a good shake. As for drying the malt, they kept things simple. They’d spread it out on the ground and let the sun do the work. Back in those days, it seems like malt was mainly used for making drinks.
The Evolution of Floor Malting Techniques
In the historical trajectory of malt production, the limitations imposed by the availability of natural wells led maltsters to adopt man-made cisterns and natural caves for steeping grains. However, the quest for improved efficiency and control over the malting process eventually catalyzed advancements primarily in central European countries. This engendered the advent of malt houses—sophisticated structures designed to regulate temperature and humidity artificially.
In terms of architecture, the earliest malt houses were typically situated at the bottom of hills or mountains, adjacent to streams, thereby enabling the gravity-fed supply of cold water. These buildings were constructed with thick stone walls and floors made of either stone or mortar. Ventilation was minimal, limited to small windows set in the heavy walls. The barley grains were loaded into the upper part of the house and transferred to deep cisterns for the steeping phase. Subsequently, the grains were moved to a stone floor for germination.
As the germination process began and the grains generated heat, the malt was manually shoveled into a thin layer towards the front of the room to control temperature. Further cooling was carried out during the evening or nighttime, when the thin malt layer would be moved to another spot on the floor, thrown into the air, and allowed to descend as a fine shower. Moisture levels were managed using rudimentary watering cans.
The subsequent transfer of malt for kilning, or drying, involved shoveling the fully germinated malt through trapdoors into wheelbarrows. These wheelbarrows would then transport the malt to kilns equipped with tile floors and simple furnaces. Ventilation relied exclusively on natural drafts, subjecting the malting process to the vagaries of weather conditions. In this traditional system, the maltster, through refined manual techniques, personally managed all aspects of production, including temperature regulation primarily based on sensory perception.
Due to the natural draft system’s vulnerability to weather conditions, malting was largely a seasonal enterprise, confined to cooler months, which averaged about five months per year. This seasonal constraint significantly limited the volume of malt that could be produced, necessitating the malt house to remain closed during the warmer months.
In essence, the primitive form of floor malting was shaped by an intricate balance between human craftsmanship and environmental limitations. The maltster’s expertise was pivotal in achieving the desired malt characteristics under such rudimentary and weather-dependent conditions. The introduction of malt houses signified a critical juncture in the evolution of malting techniques, marking a transition from dependence on natural processes to an incipient form of controlled, artificial means.
Journey from Manual Labor to Mechanization
The fundamental methodology of early malt houses remained relatively constant for an extended period, though efforts to enhance production were continuous. It was not until the advent of steam power, and subsequently electrical power, that the malting process experienced a significant transformation. While there may have been isolated attempts to utilize water-driven bellows for ventilation, evidence for such innovations remains inconclusive.
The introduction of modern power sources facilitated the incorporation of ventilating fans and water pumps into pre-existing malt houses. This marked the first substantial deviation from traditional methods. As technology advanced, newer facilities were erected that took full advantage of the capabilities enabled by modern power. In these early iterations of contemporary malt houses, steel tanks replaced antiquated cisterns, larger fans were utilized for more effective ventilation, and comprehensive sprinkler systems were installed. Despite these advancements, manual labor persisted, particularly in the form of hand shoveling on old masonry floors. It was in this hybrid environment of traditional and modern practices that malt achieved its current standing in the market.
The subsequent innovation involved the adoption of the compartment system, a more modern architectural approach. In this system, soaked barley is laid out on perforated flooring, allowing for the circulation of moist, cool air that is controlled by fans. The malt is agitated by substantial mechanical turners that periodically rearrange the grains. Upon completion of the germination process, the malt is transferred to mechanical conveyors using automated shovels. The conveyors then deposit the malt in kiln houses fitted with perforated metal floors. Unlike their predecessors, these floors are sectional and can be opened to allow the malt to be transported further. Advanced kiln technology now enables moisture content to be reduced to as low as 3 percent.
Post-drying, the malt is funneled directly into hoppers situated beneath the kiln floors. These hoppers are connected to conveyors that move the finished product to facilities for cleaning and storage. The overarching objective of contemporary malt houses is not solely to maximize production within a confined space but also to significantly mitigate manual labor through automation.
Notwithstanding the extensive technological advancements, the intrinsic properties of malt have remained remarkably consistent over centuries. The only discernible alteration lies in the improved quality of barley strains that have been cultivated. Overall, the technological evolution in malt houses exemplifies the seamless integration of modern power and mechanization into a historically manual and labor-intensive process.
Weyermann's malting process diagram
Saladin Box Malting System
Drum Malting System
In the production of malt, the triad of essential phases—steeping, germination, and kilning—often garners significant attention. Yet, it is imperative to acknowledge that these foundational steps are augmented by a plethora of subsidiary processes, each synergistically contributing to the ultimate aim of generating premium-quality malt with high degrees of reproducibility and repeatability across diverse production runs. Although the particular techniques implemented may diverge based on the idiosyncrasies of individual malthouses, the cardinal objectives persist as invariant: namely, to warrant that the resultant malt conforms to rigorous quality criteria and exhibits traits that are amenable to consistent replication.
In the early days of malting, the process was considerably less mechanized than it is today. Once the grain had been soaked and germination was underway, it was moved to a concrete floor. There, it was spread to a depth of approximately six inches. Human labor played an essential role at this stage, with workers manually turning and moving the grain. This prevented the tiny rootlets from sticking together while also serving to disperse carbon dioxide, slow down the drying process, and regulate temperature.
The time it took for the grain to germinate in these early malting operations could span up to ten days, which is notably longer than the five-day period typical in modern malting facilities. Ventilation was achieved through natural means, with fresh air circulating above the grain bed. It wasn’t until the late 19th century that the concept of pneumatic malting came into play, which involved forcing air through the grain bed to aid in germination and drying.
Today, floor malting is an uncommon practice, mostly overshadowed by more efficient, automated methods. However, some malthouses still maintain this traditional technique. There is a school of thought among certain brewers and distillers that floor malting yields a malt of superior complexity and flavor. Because of this belief, you’ll often find floor-malted grain used in the production of beers that aim to preserve traditional brewing methods.
Floor malting is an ancient, labor-intensive practice that has largely given way to automated, pneumatic systems. Yet, it holds a nostalgic and, some say, qualitative appeal that keeps it alive in the world of specialty brewing.
The Saladin box stands as a seminal innovation in the field of malting, dating back to the late 19th century. Before delving into its complexities, let’s understand what malting is: it’s a process where grains are made to germinate and then dried in kilns to halt the germination. This prepares the grains for brewing, an essential part of making beer and other alcoholic beverages.
Simply, a Saladin box is a big, rectangular container fitted with rotating screws that help mix and move grains around while they’re germinating. Before this invention, workers had to laboriously shovel and rake the grains by hand every eight hours to keep them from clumping together. The rotating screws, known as augers, took on this exhausting task, making the whole process much easier and less time-consuming.
Why is it important to move grains around during germination? There are three key reasons. First, the rotation prevents the tiny roots that sprout from the grains, known as rootlets, from tangling and forming clumps. Second, this movement releases carbon dioxide, a gas that can be harmful to the grain in large quantities. Finally, it helps maintain a consistent temperature throughout the grain bed, which is vital for successful germination.
The Saladin box also paved the way for something known as pneumatic malting. This is a fancy term for a process where cool air is blown through the germinating grains. This does two things: it removes carbon dioxide and replaces it with fresh oxygen. As a result, grains germinate more quickly and efficiently.
Once the grains have finished germinating, they become what is known as ‘green malt.’ This green malt is then transferred to kilns where it’s dried to become the finished malt, ready for brewing.
The Saladin box revolutionized malting in several ways. It made the process far more efficient by automating what used to be manual labor. It allowed for more grains to be processed at once, as the automated system meant grains could be stacked deeper in the container, utilizing space more efficiently. Thus, the Saladin box has not only simplified the life of maltsters but has also made the malting process more efficient, a development that has had a lasting impact on the brewing industry.
Traditional malting techniques have relied on floor malting, wherein grains are spread out on large floors and allowed to germinate. Though romanticized for its age-old methodology, floor malting is labor-intensive and lacks the precision offered by more modern techniques. Drum malting, a mechanized alternative, came into existence to mitigate these shortcomings.
The drum malting process uses a rotating drum, similar to a large cylinder, to hold and turn the grains during the malting process. As the drum rotates, it ensures even exposure to moisture and heat, allowing for a more consistent product. One of the immediate advantages of drum malting is the uniformity it provides, making the process highly controllable and scalable. The cylindrical structure is divided into compartments, allowing for the separate stages of soaking, germination, and drying to occur in a single vessel. This self-contained nature of the drum reduces the risk of contamination, a serious concern in brewing science.
Drum malting is particularly efficient when it comes to energy consumption. Unlike traditional methods that require separate vessels and transfers, the drum malting system centralizes the operations, cutting down on energy costs. Additionally, the automation allows for greater control over the parameters of the process, such as temperature and humidity, ensuring a higher-quality product. These technical advantages have made drum malting increasingly popular, especially for larger brewing operations that require high volumes of consistent, quality malt.
However, the transition from traditional methods to drum malting is not merely a straightforward substitution; it is a complex process that necessitates an in-depth understanding of the nuances of each step involved. For instance, the speed at which the drum rotates must be meticulously calibrated to ensure that the grains are neither underturned, which would result in uneven germination, nor over-turned, which could lead to mechanical damage. Such precise control over the mechanical aspects of the process is pivotal in determining the quality of the final malt.
Furthermore, while drum malting offers a plethora of advantages, it is not devoid of challenges. One significant limitation is the capital cost of setting up the drum malting system. The intricate machinery and control systems required make it a substantial initial investment. Additionally, the complexity of the machinery demands a skilled workforce to operate and maintain it, making the process less accessible for smaller brewing operations.
The humanization of drum malting arises from the delicate balance between automation and craftsmanship. While the mechanical components offer precision and scalability, the expertise of the brewer remains indispensable. The brewer’s role shifts from manual labor to that of a knowledgeable overseer who understands not just the mechanics but also the biochemistry involved in malting. In this capacity, the brewer fine-tunes the parameters, adjusts variables as needed, and ensures the end product meets the desired quality standards.
Although the malting process might seem antiquated to some, technological advancements have significantly improved its efficiency and precision. One of the most impactful innovations in this area is the implementation of pneumatic systems. While the term “pneumatic” often conjures images of complex machinery, its role in modern malting procedures can be remarkably straightforward yet effective.
Pneumatic systems operate on the principle of compressed air to move and control materials. The system comprises an air compressor, valves, and actuators connected through a series of pipes. The air compressor provides the energy required to mobilize the barley grains or activate machinery for various tasks like transferring, aerating, and drying the grains. Valves and actuators serve as the “hands and fingers” of the system, managing the flow and direction of the grains and air throughout the malting process.
Pneumatic systems humanize the intricate world of malting? To begin, let’s focus on the efficiency they offer. Time is a scarce commodity, particularly in industries that demand high throughput. Pneumatic systems expedite the malting process by automating several key activities, from grain handling to aeration. This efficiency does not merely translate into a faster production cycle; it also enables brewers to focus on the nuances that make each malt—and by extension, each beer—unique. By alleviating the workload, pneumatics free up human expertise for the pursuit of quality and innovation.
Secondly, pneumatics offer enhanced reliability and precision. Unlike manual operations, which are prone to inconsistencies, pneumatic systems follow a pre-set program to ensure uniformity in the malting process. This level of reliability is crucial for achieving consistent quality in the final product. Any deviations in the malting procedure, such as temperature or moisture inconsistencies, can have far-reaching implications on the beer’s taste and aroma. Through automated controls, pneumatic systems minimize the risk of such inconsistencies, making it easier for brewers to produce high-quality malt.
Thirdly, the integration of pneumatic systems results in better safety measures. Manual handling of grains and machinery can be risky and labor-intensive, posing challenges to both worker safety and well-being. Compressed air systems can be equipped with sophisticated sensors and safety features that mitigate risks such as mechanical failure or fire hazards, thereby ensuring a safer work environment.
Despite their numerous advantages, it’s worth acknowledging the initial investment cost associated with implementing pneumatic systems. Another point of consideration is the environmental impact. Compressed air systems consume energy, and their environmental footprint is contingent on the source of that energy. Nonetheless, advancements in energy-efficient compressors and renewable energy sources are steadily mitigating this concern.
Steeping is a vital initial stage in malt production, a key ingredient for brewing beer. The process starts with raw barley seeds, which have been dried to around 12% moisture to be safely stored. These seeds are first cleaned to remove any unwanted particles like small rocks, broken pieces, and other contaminants. The cleaned barley is then placed in a water tank and soaked for several hours. This soaking period is what we call “steeping.”
The main goal of steeping is to kickstart the barley seeds’ natural growing processes. In simpler terms, it “wakes up” the seed. To do so, the seed’s moisture content needs to reach about 30–35%. This gets the seed ready to grow, or as scientists would say, activates the enzymes and starts germination. It’s a bit like the seed taking its first breath and starting its life journey, a process that involves turning sugar into energy, carbon dioxide, and water. To ensure this chemical transformation takes place smoothly, the steeping process alternates with periods where the barley is left to rest in the open air. These “air rests” serve to provide the seeds with fresh oxygen and help remove any excess carbon dioxide and heat. If we didn’t do this, the seeds would essentially “drown” because they wouldn’t get the oxygen they need.
Steeping also serves another practical purpose: it cleans the barley. The soaking water helps to remove any leftover bacteria and dust from the seeds. By the end of the steeping phase, the moisture content of the barley will have risen to around 44–48%, making it ready for the next steps in the malting process.
In terms of specifics, steeping isn’t a one-size-fits-all operation. The length of time the barley is soaked in water, and the duration of air rests, can vary depending on the kind of malt you’re aiming to produce and the characteristics of the barley itself. Generally, the process involves two or three rounds of steeping, each lasting around four hours. The water temperature is usually maintained between 55–64 degrees Fahrenheit. Similarly, air rests typically last around 20 hours. By the end of the entire steeping process, you’ll notice that most of the seeds develop a small white spot at the base. This spot, known as the achit, signifies that the seed’s root is ready to break through its outer layer, indicating the successful completion of the steeping stage.
Weyermann's Germination Box
In the process of making malt for beer, one key step is letting the soaked grains sprout. This step is known as germination. To understand why germination is so crucial, it’s essential to know that a grain seed has all the elements to grow a new plant. Before the seedling can perform photosynthesis to make its own sugar, it has to tap into its stored starch.
To convert this stored starch into energy-giving sugar, the seed produces special proteins called enzymes, specifically amylases. These enzymes break down the complex starches into simpler sugars that the seed can use for growth. Another important aspect during this step is breaking down the seed’s outer cell walls so that these enzymes can more easily access the starch. All these changes that happen in the grain during germination are grouped under the term “modification.”
Getting this modification just right is crucial for making good malt and, by extension, good beer. Too much modification means the seed uses up the sugar, leaving less for the beer-making process. Traditional ways of germinating involve spreading the soaked grains on a floor and manually turning them over with rakes. But modern methods use machines and special containers like Saladin boxes to automate this turning, allowing for a deeper pile of grains.
During the germination, it’s vital to ensure that the grains are exposed to oxygen while allowing the carbon dioxide and heat to escape. The grains are usually kept at a temperature between 64–72°F and are germinated for around four days. Water content in the grain, usually aimed to be around 40%, is essential to kickstart the process. The water activates the seed’s hormones, which travel to specific layers within the grain to regulate the production of the needed enzymes.
The sprouting grain produces a shoot known as the acrospire. The length to which this shoot grows is a simple way to gauge the progress of germination. For lighter malts used in pilsners and pale beers, the acrospire is usually allowed to grow to about two-thirds or three-quarters of the grain’s length. For darker malts, it can grow longer.
Interestingly, the plant hormones controlling this process belong to a family known as gibberellins. Some producers expedite the germination by spraying the grain with a synthetic form of these hormones, called gibberellic acid (GA). However, most malt producers avoid using GA, and its use is even considered a violation of the German beer purity law, known as the Reinheitsgebot.
Germination is not just a simple sprouting process; it’s a carefully regulated series of biochemical events. Getting it right is crucial for making malt that will ultimately become part of the beer’s flavor, aroma, and body.
Kilning is the process where we halt the germination of malt by drying it. The way you dry the malt can greatly affect its flavor, making this an essential step in malt production. Before it is dried, malt is referred to as ‘green malt.’
To dry malt, hot air is pushed through a pile of it in a machine known as a kiln. The specifics of this procedure can differ depending on what type of malt the maltster is aiming to create. For what’s known as ‘base malt,’ the drying process has three main phases.
In the first phase, known as ‘free-drying,’ the kiln blows air heated to around 50°C (122°F) to remove water from the surface of the grains quickly. As the air moves through the grain, it cools down and becomes more humid, eventually emerging from the kiln filled with moisture. This stage continues until the inner temperature of the grains also reaches around 50°C. At that point, the air starts to get hotter because it has already evaporated most of the easily removable water.
The second phase is called ‘diffusion drying.’ Here, the focus is on removing the moisture that is still inside the grain kernels. The moisture content of the grain drops to about 10-15%. During this stage, the airflow is reduced, and the air’s temperature is raised to between 65 and 75°C. It’s essential to be cautious at this phase because malt enzymes can break down due to the moist conditions and the elevated temperatures. The air leaving the kiln at this point is pretty dry and can be used to dry another batch of malt.
In the third and final phase, known as ‘curing,’ the temperature is bumped up again, this time to between 80 and 110°C. This temperature depends on whether you want the malt to be pale or dark. By the end of this stage, the moisture content is down to about 4%.
Throughout all these stages, the kilning process is carefully controlled to keep important enzymes like amylase active. These enzymes are crucial for the brewer during the next step, known as the ‘mashing process.’ The whole drying process takes about two days to complete.
Once the malt is dried, the stalks, which have become brittle from the heat, are mechanically removed. The malt then undergoes a cooling phase, after which it is cleaned by passing it through a sieve. It is then stored for at least three weeks before it’s ready for brewing. This storage period is not just a waiting game; it actually helps to even out the moisture levels in the malt and stabilizes its flavor, ensuring that it performs better in subsequent brewing steps.
After the processes of kilning or roasting have been completed, it is imperative to cool the malt to a temperature ideally no higher than 20 degrees Celsius (68 degrees Fahrenheit). Failure to achieve this cooling milestone has several negative implications. First, residual heat in the stored malt will perpetuate color alterations and enzymatic breakdown, thereby altering the malt’s intended properties. Second, in the case of special malts or roasted barley that originate from roasting drums, immediate placement in a cooling chamber with strong ventilation is standard practice. This not only mitigates further unintended color changes but also minimizes the potential risk of combustion.
In the post-kilning stage of malt production, it is essential to undergo a deculming process to remove rootlets, dust, and broken corns from the malt. This procedure is not merely a preparatory step but is imperative for optimizing the quality of the final malt product. The rootlets and dust are not only hygroscopic—meaning they easily absorb moisture from the atmosphere—but are also rich in soluble nitrogenous substances, bitter compounds, sulfur dioxide, and/or nitrosamines. Their presence can detrimentally affect the overall flavor and quality of the brewed beer. Thus, they are systematically eliminated through methods of agitation, sieving, and aspiration.
The timing of deculming is pivotal. Ideally, it should occur immediately after the malt has been removed from the kiln to facilitate cooling and to prevent the rootlets from acquiring moisture from the air. Once rootlets absorb moisture, they become less brittle, making them harder to break and separate. In this phase, the aspirating airstream collects the separated rootlets and dust for removal.
Before the malt is shipped out from the storage facility, additional measures may be taken to ensure its quality. A secondary screening and aspiration can be employed to eliminate any remaining broken corns, separated husks, and other contaminants. While less common, some malt may be subjected to destoning or polishing, the latter being essentially a cosmetic procedure that removes lingering dust and mold spores by passage between vegetable-fiber brushes.
Deculming can be achieved through various methods. Although it is technically possible to remove the most dense, under-modified malt corns through a shaking table, in smaller, artisanal brewing setups, this method is seldom used in practice due to its time-consuming nature. Mechanical deculmers are frequently employed in large-scale brewing operations, where they function to efficiently separate the barley grains from their stalks. Overall, these post-kilning processes are meticulously conducted to ensure that the malt meets the rigorous standards necessary for producing high-quality beer.
Brewing beer is both an art and a science, featuring multiple steps that each bring something special to the end product. Within these steps, the treatment of barley malt stands out as a pivotal moment. Whether the malt is smoked, roasted, or toasted, each process plays a critical role in defining what the beer will ultimately become. The choices made here can lead to a variety of results, from a light, crisp ale to a dark, robust stout.
In essence, the transformation of barley malt is not just a minor, forgettable step in beer production. Rather, it’s a defining stage that influences the very character of the beer, affecting its flavor, aroma, and how it feels in your mouth. So the next time you enjoy a glass of beer, consider the craft and science behind it, especially the crucial role played by the treatment of barley malt.
Roasting or Toasting
The terminology “roasting” and “toasting” often seem interchangeable, but they denote distinct heat treatment methods. Roasting involves high temperatures and a longer period, resulting in a darker color and a more intense flavor profile. Think of it as analogous to the dark roast in coffee, which is strong and robust. Toasting, on the other hand, employs lower temperatures for a shorter time, leading to a subtler flavor and lighter color. This could be likened to a light roast in coffee, which is more aromatic and milder.
Roasting typically involves temperatures ranging from 350°F to 450°F and can last for 15 to 45 minutes. The high heat catalyzes the Maillard reaction, a chemical interaction between amino acids and reducing sugars. This reaction is responsible for the brown hue and the complex flavors that often have undertones of caramel, chocolate, or even burnt nuances. Dark beers like stouts and porters frequently incorporate roasted malts.
Toasting is generally conducted at temperatures around 250°F to 350°F, lasting anywhere between 10 and 30 minutes. The lower temperature doesn’t induce the Maillard reaction to the same extent as roasting, which means that the flavors and colors are lighter. Toasted malts are commonly used in ales, ambers, and brown beers.
The complexities of roasting and toasting extend beyond just temperature and time. The moisture content in the malt, the size of the grain, and even the mineral composition of the water used can affect the end result. Advances in technology have also led to more consistent and controllable heating techniques, such as convection roasting, which circulates hot air for an even roast, and drum roasting, where the grains are tumbled in a rotating drum, akin to how coffee beans are often roasted.
What is fascinating is how these variations can result in a remarkably broad spectrum of beer types. From the light, floral notes of a pale ale to the smoky, full-bodied richness of a stout, it is the carefully calibrated roasting and toasting process that provides the foundational flavors.
In the malting process, grains that have undergone germination are subjected to further drying and curing on a perforated wooden surface. This floor is heated by smoke emanating from an oasting fireplace, conveyed through specialized channels. The typical temperature maintained for this procedure is approximately 55°C (131°F). Such malt is commonly referred to as Smoked Malt and is a principal ingredient in the crafting of smoked ales or lagers. However, it should be noted that the primary application of smoked malt is in the production of whisky, particularly in the genre of Scotch whisky.
Numerous traditional Scottish distilleries, some of which still engage in in-house malting, depend on malt that has been dried and cured in ovens fueled by peat. Peat imparts a characteristic smoky flavor but also renders the malt exceptionally acrid. Consequently, its application in brewing beer is notably limited. When peated malt is incorporated into the brewing process, it is not used as a base malt. Rather, it is sparingly added to the grist, the mixture of grains used in brewing, in such minimal quantities as to impart only a subtle flavor profile to the resultant brew.