The world of dark ales owes its rich color and complex roasted flavors to a variety of highly kilned malts. Among the most common choices for achieving these characteristics are roasted barley and Carafa I. While roasted barley is a popular staple, some brewers harbor concerns that it can introduce an undesirable burnt or acrid note to their beers. Conversely, Carafa I is frequently lauded for imparting a smoother, more refined roast character, often attributed to its dehusked nature.
This ongoing debate prompts a crucial question for homebrewers: how significant are the perceived differences between these two specialty malts in a finished beer? In the accompanying video, Brülosophy contributor Will Love bravely takes on this brewing challenge, conducting an exBEERiment focused on comparing Carafa I vs. Roasted Barley in an Altbier. This detailed exploration delves into his brewing process, the meticulous sensory evaluation, and the insightful results that challenge conventional wisdom, offering valuable lessons for every homebrewer.
Understanding Dark Roasted Malts: Carafa I vs. Roasted Barley
Before diving into the experiment, it’s essential to grasp the fundamental differences and perceived qualities of the malts in question. Roasted barley is simply barley grains that have been subjected to intense kilning, resulting in a dark, often coffee-like flavor with notes of toast and chocolate. However, because its husks remain intact during roasting, it can sometimes contribute astringent or bitter notes, often described as ‘burnt’ or ‘acrid,’ especially when used in larger quantities or certain beer styles.
Carafa I, on the other hand, belongs to a family of dehusked roasted malts. This key distinction means the husks are removed prior to roasting, which significantly reduces the potential for harshness or bitterness. Consequently, Carafa I is often chosen for its ability to provide deep color and smooth, clean roasted flavors without the risk of acridity. Its flavor profile tends to lean towards softer chocolate or mild coffee notes, making it a favorite for styles where a gentler roast character is desired, like Altbiers or dark lagers.
Malt Characteristics and SRM Ratings
The experiment utilized Carafa I, coming in at approximately 320 SRM (Standard Reference Method), which indicates a very dark color. For comparison, Will also mentioned a Brises roasted malt he had on hand, rated around 400 SRM. The SRM scale is a common method for brewers to measure beer and malt color, with higher numbers indicating darker shades. Even a seemingly small difference in SRM, like between 320 and 400, can visually impact a beer, yet the crucial factor often lies in the sensory contribution beyond just color.
The primary goal was to discern if these technical differences in processing and SRM would translate into a perceptible sensory variation in the final Altbier. An Altbier, a traditional German amber ale, is an excellent candidate for this kind of experiment. It’s a clean, balanced style that doesn’t have a robust hop profile or heavy adjuncts to mask subtle malt nuances. This style allows the roast character of the specialty malts to truly shine, or betray any unwanted flavors.
Crafting the Altbier Recipe: The Brüh Club Influence
The foundation for this experiment’s Altbier recipe came from a collaborative effort within the Brüh Club, a quarterly brewing group. Members vote on various parameters, from ingredients to processes, to establish a baseline recipe for their brews. This democratic approach ensures a broad consensus, yet often encourages individual brewers to “bend the rules” slightly, leading to interesting variations. Will’s malt bill for this particular Altbier largely adhered to these voted-upon guidelines, providing a solid and representative base for the experiment.
The grist, or grain bill, for the Altbier was carefully constructed to highlight the variable malts while supporting the overall style. The dominant base malt was 10 pounds of Llano Pilsner malt, constituting a significant 85% of the total grist. This provided a clean, fermentable sugar base typical of many German-style beers. Adding depth and a touch of bready sweetness was 1 pound of Munich malt, making up about 8.5% of the grist. Caramunich malt, at 4 ounces (2% of the grist), further contributed caramel and body notes, essential for an authentic Altbier character.
Crucially, the experimental variable was 8 ounces of either Carafa I or roasted barley, each accounting for approximately 4.3% of the grist. This small, yet impactful, percentage was deemed sufficient to introduce the characteristic roast flavors and colors of these malts without overwhelming the delicate balance of the Altbier. Such precise formulation ensured that any detected differences could be directly attributed to the variable specialty malt, making the comparison robust.
The Brew Day: Precision and Process for the Carafa I vs. Roasted Barley Experiment
Executing a side-by-side brewing experiment demands meticulous planning and execution to ensure that the only significant variable is the one being tested. Will found that integrating the variable early in the brew day, specifically by preparing two separate grists (one with Carafa I, one with roasted barley), simplified the overall process. This method ensures that apart from the specialty malt, all other parameters—water, temperature, timing, and hop additions—remain identical for both batches.
The mash, a critical stage for enzymatic conversion of starches into fermentable sugars, was consistently held at 152°F (66.7°C) for 60 minutes. This temperature typically produces a balanced fermentability, contributing to a medium-bodied beer. Will opted for a no-sparge method, where the wort is simply drained from the mash tun without an additional rinse of hot water. This technique can simplify the brew day and often results in a richer, more concentrated wort, though it may yield slightly lower efficiency.
Once the mash was complete and the wort separated, the boiling phase commenced. The hop schedule was identical for both batches, designed to provide both bitterness and noble hop aromatics characteristic of an Altbier. The bittering addition comprised 15 grams of Magnum hops at 60 minutes, providing a clean, firm bitterness. For aroma and flavor, 55 grams of Tettnanger hops were added at 30 minutes, followed by another 55 grams at 5 minutes, contributing traditional spicy and floral notes.
Leveraging Modern Brewing Technology: Refractometers and Glycol Rigs
Modern homebrewing has been significantly enhanced by advanced equipment, exemplified by Will’s use of a digital refractometer. This device allows for precise gravity readings with just a few drops of wort, minimizing sample waste compared to traditional hydrometers. It’s particularly convenient during the brew day, providing quick and accurate measurements of sugar concentration, which helps brewers track their efficiency and ensure their wort is on target before fermentation.
Furthermore, Will utilized a state-of-the-art glycol rig setup with Delta Ferment Tanks, particularly the new tri-clamp varieties. This system provides superior temperature control during fermentation. After cooling the wort to approximately 80°F (26.7°C) with a chiller, the glycol rig swiftly brings the wort down to the desired pitching temperature and maintains it throughout the fermentation cycle. This precision temperature control is paramount for producing clean, consistent beers, especially for styles like Altbier where off-flavors from temperature fluctuations would be easily noticeable.
After four days of primary fermentation, the temperature was raised to 68°F (20°C) for another four days, a common practice for diacetyl rest or ensuring complete fermentation. Unsurprisingly, both batches achieved the same final gravity of 1.011. This consistency underscores that the 8 ounces of highly kilned specialty malts contribute negligible fermentable sugars, primarily influencing color and flavor rather than fermentability. Achieving identical gravities validated the consistency of the brewing process, assuring that any perceived differences would be due to the Carafa I vs. Roasted Barley variable.
The Sensory Showdown: Triangle Testing the Dark Malts
The true test of the Carafa I vs. Roasted Barley experiment lay in sensory evaluation. While visually both beers appeared strikingly similar, with only a very subtle difference in darkness sometimes perceivable under specific lighting, the critical question was whether tasters could detect a difference in flavor or aroma. The primary method for this was a triangle test, a standard sensory evaluation technique designed to determine if a perceptible difference exists between two samples.
In a triangle test, participants receive three samples, two of which are identical and one that is different. The task is to identify the unique sample. This method minimizes bias and forces tasters to focus on subtle differences. Will himself undertook an initial series of triangle tests, scoring 3 out of 6 correct identifications, a 50% accuracy rate. While he perceived “a touch more roastiness” in one sample, his overall score was insufficient to demonstrate a reliable ability to distinguish between the two beers.
Blind Taster Results and Statistical Significance
To further validate the findings, 20 blind tasters participated in the experiment. Each was served one sample of the Carafa I Altbier and two samples of the roasted barley Altbier, presented in different colored cups to ensure true blindness. For the results to achieve statistical significance, meaning the difference was unlikely due to chance, 11 out of the 20 tasters would need to accurately identify the unique sample. However, only 7 tasters managed to do so.
This result, falling short of the required 11, clearly indicates that the participants could not reliably distinguish between the Altbier brewed with Carafa I and the one brewed with roasted barley. This finding is significant for homebrewers, as it suggests that in a recipe like this Altbier, the choice between these two dark malts might be less critical than commonly assumed, especially concerning concerns about “burnt” notes from roasted barley.
Flavor Perceptions and the Absence of Acridity in Roasted Barley
Will’s personal tasting notes for both beers described a “subtle nutty roast character” with “no hint of coffee, dark chocolate.” This description is crucial, as often the primary concern with roasted barley is the potential for acrid, ashy, or smoky notes. These undesirable flavors are frequently associated with the husks of roasted malts, and are a main reason brewers might opt for dehusked varieties like Carafa I.
The fact that even the roasted barley version did not exhibit these acrid qualities in this particular Altbier recipe is a powerful testament. It suggests that, in appropriate concentrations (4.3% of the grist in this case), and within the context of a well-designed malt bill, roasted barley can contribute desirable roast flavors without the feared harshness. This observation opens up flexibility for brewers who may have previously avoided roasted barley in certain styles due to apprehension.
The discussion around acridity naturally extends to other highly roasted malts, such as Black Patent malt, which is notoriously potent and often contributes strong coffee and burnt notes. Will mentioned that Brülosophy has previously shown Black Patent also to be non-significant in some other experiments, suggesting that the perception of these malts might be more nuanced than widely believed. The key often lies in careful formulation and understanding how different malts interact within the broader recipe.
Competition Validation and Practical Takeaways
Adding another layer of validation to the Carafa I vs. Roasted Barley experiment, the Altbier (specifically the roasted barley version) received a bronze medal in the Hot and Humid competition in Florida. A bronze medal signifies that the beer was a good representation of the Altbier style, exhibiting commendable quality and adherence to style guidelines. This external, unbiased evaluation further reinforces the notion that the roasted barley did not introduce any off-flavors detrimental to the beer’s quality or style fidelity.
The combined evidence from Will’s personal assessment, the blind tasters’ inability to differentiate, and the competition medal points to a clear practical takeaway for homebrewers. For an Altbier recipe of this type and with these proportions, Carafa I and roasted barley are largely interchangeable. This offers significant flexibility in ingredient selection. If a brewer has one on hand, or if one is more readily available or cheaper, they can confidently use either in their next Altbier recipe without significant impact on the final sensory experience.
Your Altbier exBEERiment: Malt Comparisons and Brewing Questions
What are Carafa I and Roasted Barley?
Carafa I and Roasted Barley are types of dark roasted malts used in homebrewing. They are added to beer recipes to contribute deep color and specific roasted flavors.
What is the main difference between Carafa I and Roasted Barley malts?
The key difference is that Carafa I has its husks removed before roasting, which is often said to result in a smoother roast flavor. Roasted barley is roasted with its husks intact.
Why do brewers use these dark malts in their beer recipes?
Brewers use these malts primarily to give dark beers their rich color and to impart complex roasted flavors, which can include notes of coffee, chocolate, or toast.
What was the main conclusion of the experiment comparing Carafa I and Roasted Barley in an Altbier?
The experiment found that blind tasters could not reliably distinguish between the Altbier brewed with Carafa I and the one brewed with roasted barley. This suggests the flavor differences were not easily perceptible in this specific recipe.
What does this experiment mean for homebrewers choosing between these two malts?
For an Altbier recipe with similar proportions, homebrewers can likely use either Carafa I or roasted barley interchangeably. It suggests that concerns about roasted barley causing ‘burnt’ flavors might be less critical than often assumed at moderate concentrations.
