Clone Recipe: Birra Moretti

Cloning Birra Moretti involves crafting a crisp, sessionable Italian pale lager. My technique focuses on a precise Pilsner malt base with flaked maize, subtle noble hopping for 18 IBU, and a clean fermentation with Saflager W-34/70 at 12°C, including a vital diacetyl rest, to achieve its signature light body and refreshing character. Consistency in temperature and ingredient quality is paramount.

The Brewer’s Hook: Chasing the Crisp, Clean Lager Profile

When I first set out to clone a classic Italian pale lager, I made the mistake of underestimating the subtleties. My initial attempt, years ago, used an ale yeast fermented cold, thinking “cold” was “lager.” The result was an overly fruity, somewhat muddled beer that completely missed the clean, crisp mark. It was drinkable, sure, but it wasn’t the sparkling, refreshing lager I aimed for. That experience taught me an invaluable lesson: achieving a truly authentic lager profile demands not just cold fermentation, but specific lager yeast strains, meticulous temperature control, and a deep understanding of the enzymatic processes during the mash. It took several iterations, tweaking everything from mash temperature to hop timing, to finally nail that elusive balance. My journey led me to refine my process, ensuring that every batch brewed for BrewMyBeer.online embodies the true character of the style.

The Math Behind the Moretti Clone: A Manual Calculation Guide

Brewing isn’t just art; it’s applied science. To truly understand and replicate a beer, you need to dissect its components. Here, I’ll break down the mathematical underpinnings for our 20-liter (5.28-gallon) Birra Moretti clone.

Grain Bill Percentages & Yield

The foundation of any beer is its malt. For this clone, we’re aiming for a light body and a pale color, typical of an Italian pale lager. My choice of grains and their percentages are as follows:

To calculate our theoretical Original Gravity (OG), assuming 75% brewhouse efficiency:

• Pilsner Malt contribution: (3.5 kg / 0.4536 kg/lb) * 37 PPG = 285.4 gravity points
• Flaked Maize contribution: (0.5 kg / 0.4536 kg/lb) * 37 PPG = 40.8 gravity points
• Total points = 285.4 + 40.8 = 326.2 points for 1 gallon.
• For 5.28 gallons (20L), theoretical points = 326.2 / 5.28 = 61.78 points.
• Theoretical OG = 1.061.78.
• Applying 75% efficiency: 1.000 + (0.06178 * 0.75) = 1.0463. So, an OG of 1.046.

Bitterness Calculation (IBU)

Birra Moretti has a gentle bitterness. We’re aiming for 18 IBU. I use a simplified Garetz formula for homebrewing, which takes into account boil time, hop alpha acids (AA%), and wort gravity. For a 20L batch:

The IBU calculation is complex, factoring in hop utilization, which is affected by boil gravity, boil vigor, and hop form. For a 30g addition of 4.0% AA Hallertau at 60 minutes in 20L of wort with an average boil gravity of 1.035, my brewing software predicts around 18 IBU. This is a crucial detail often overlooked in simpler recipes.

ABV Calculation

Once you have your OG and FG, calculating ABV is straightforward:

ABV = (OG – FG) * 131.25

For our target: (1.046 – 1.009) * 131.25 = 0.037 * 131.25 = 4.85625. So, approximately 4.85% ABV.

Step-by-Step Execution: Brewing Your Moretti Clone

Precision and hygiene are non-negotiable. Follow these steps meticulously for a successful brew.

1. Water Treatment & Mashing (Total Time: 90 min)

1. Gather Water: Begin with 15 liters of strike water for a 20L batch, reserving 15-18 liters for sparging. Aim for a water profile with low alkalinity and moderate calcium (e.g., Ca: 50 ppm, Mg: 10 ppm, Na: 20 ppm, SO4: 50 ppm, Cl: 80 ppm). I often start with reverse osmosis water and add brewing salts.
2. Heat Strike Water: Heat your strike water to 71°C (160°F) to achieve our target mash temperature after grain addition.
3. Dough In: Slowly add your milled grains (3.5 kg Pilsner Malt, 0.5 kg Flaked Maize) to the strike water, stirring vigorously to prevent dough balls. Ensure the mash temperature stabilizes at 65°C (149°F). This single-infusion rest optimizes beta-amylase activity for a fermentable wort, crucial for the dry finish of a lager.
4. Mash Rest: Maintain 65°C (149°F) for 60 minutes. Insulate your mash tun well.
5. Mash Out: After 60 minutes, slowly raise the mash temperature to 76°C (168°F) using direct heat or by adding boiling water. Hold for 10 minutes. This halts enzymatic activity and reduces wort viscosity for better lautering.

2. Lautering & Sparge (Total Time: 60-90 min)

1. Recirculation (Vorlauf): Gently draw off wort from your mash tun and return it to the top of the grain bed until the wort runs clear. This sets the grain bed as a filter.
2. First Runnings: Begin collecting your first runnings into your boil kettle.
3. Sparging: Once the grain bed is exposed, slowly add your pre-heated sparge water (77°C / 170°F) evenly over the grain bed, ensuring the grains are always covered. Collect until you have approximately 25 liters (6.6 gallons) of pre-boil wort. My target pre-boil gravity is usually around 1.038-1.040.

3. Boil (Total Time: 90 min)

1. Bring to Boil: Vigorously bring your wort to a rolling boil. Skim off any hot break material that forms.
2. Hop Addition (60 min): Once boiling, add 30g Hallertau Mittelfruh (4.0% AA) for your bittering addition.
3. Boil for 90 Minutes: Maintain a strong, rolling boil for the entire duration. This ensures good hot break formation, sterilizes the wort, and drives off unwanted volatile compounds.
4. Whirlfloc/Klarspül Addition (10 min): At 10 minutes remaining in the boil, add a fining agent like 1/2 tsp Irish Moss or a Whirlfloc tablet for improved clarity.
5. Flameout: After 90 minutes, turn off the heat.

4. Chilling & Fermentation (Total Time: 4-6 Weeks)

1. Rapid Chilling: Immediately chill your wort using an immersion chiller, plate chiller, or counterflow chiller down to 10°C (50°F). Rapid chilling helps prevent chill haze and minimizes the risk of infection.
2. Sanitize: Thoroughly sanitize your fermenter, airlock, and any equipment that will contact the cooled wort.
3. Transfer & Aerate: Transfer the chilled wort to your sanitized fermenter. Aerate vigorously by shaking the fermenter or using an oxygenation stone for 60 seconds. Proper oxygen levels are crucial for healthy yeast propagation.
4. Pitch Yeast: Pitch 2 packets (22g) of Saflager W-34/70 dry yeast, rehydrated according to manufacturer instructions, or an appropriate liquid lager yeast starter (2-liter starter for optimal cell count).
5. Primary Fermentation: Ferment at 12°C (54°F) for 7-10 days, or until gravity drops to approximately 1.012 SG. Use a fermentation chamber or temperature controller for precise control.
6. Diacetyl Rest: Once fermentation slows and gravity approaches target FG, raise the temperature to 18°C (64°F) for 2-3 days. This allows the yeast to reabsorb diacetyl (a buttery off-flavor).
7. Lagering: After the diacetyl rest, crash cool the beer to 2°C (36°F) and lager for 2-4 weeks. This cold conditioning phase is critical for clarifying the beer and mellowing flavors.

5. Packaging (Total Time: 2-3 Weeks)

Whether you keg or bottle, careful preparation is key.

1. Sanitize: Ensure all packaging equipment (kegs, bottles, tubing, caps) is meticulously cleaned and sanitized.
2. Transfer: Carefully transfer the lagered beer, minimizing oxygen exposure, to your keg or bottling bucket.
3. Carbonation:
   • Kegging: Force carbonate to 2.5-2.7 volumes of CO2. I typically set my regulator to 12-15 PSI at 2°C (36°F) and let it condition for 5-7 days.
   • Bottling: Prime with 120g Dextrose (Corn Sugar) dissolved in 250ml of boiling water, cooled, and gently mixed into the bottling bucket. This will yield approximately 2.5 volumes of CO2. Bottle condition at room temperature for 2-3 weeks, then transfer to cold storage.

Troubleshooting: What Can Go Wrong and How to Fix It

Even with experience, brewing can throw curveballs. Here are common issues and my go-to solutions.

• Cloudiness (Chill Haze/Yeast in Suspension): If your beer isn’t brilliantly clear after lagering, it’s often chill haze (protein-polyphenol complexes) or yeast. My first line of defense is ensuring I’ve hit all chilling and lagering temperatures correctly. If it persists, adding a fining agent like gelatin (1/2 tsp dissolved in 120ml warm water, added cold to the fermenter for 2-3 days) can work wonders. Filtering is an option, but I generally prefer traditional methods for homebrewing.
• Diacetyl (Buttery Flavor): This is the bane of many lager brewers. If you detect a butterscotch or movie popcorn aroma/flavor, it means your diacetyl rest wasn’t long enough or warm enough. My advice: never skip the diacetyl rest, and always taste a sample before cold crashing. If it’s already in the finished beer, unfortunately, it’s very difficult to remove completely, but extended cold conditioning can sometimes help it fade. This is why I stress precise temperature control, particularly during the diacetyl rest, at BrewMyBeer.online.
• Acetaldehyde (Green Apple/Pumpkin Flavor): This indicates incomplete fermentation, often due to pitching insufficient yeast or fermenting too cold too quickly. Ensure you pitch enough healthy yeast and maintain primary fermentation temperature until FG is stable. If detected, warming the beer slightly for a few extra days (even post-diacetyl rest) can sometimes give the yeast a chance to clean it up.
• Low Efficiency: If your OG is consistently below target, your mash efficiency needs attention. Common culprits include a coarse crush, improper mash temperature (too high or too low for optimal enzyme activity), incorrect pH (aim for 5.2-5.4 pH during mash), or poor sparging technique (too fast, or uneven water distribution). I always check my grain crush and ensure my mash pH is within range using pH strips or a meter.
• Lack of Head Retention: A thin, quickly dissipating head can be frustrating. Factors include inadequate protein levels (too much adjunct), fatty acids from poor sanitation, or excessive alcohol. Ensure you haven’t over-sparged (extracting tannins) and that your glassware is scrupulously clean (no residual oils). A small percentage of CaraPils or similar dextrin malt (100-200g) can be added to the grain bill in future batches to boost head retention if it’s a persistent issue, though not strictly traditional for this clone.

Sensory Analysis: The Birra Moretti Clone Experience

After weeks of patient brewing and lagering, here’s what you should expect from your meticulously crafted clone.

• Appearance: Pouring a glass, you should be greeted with a brilliant, clear golden straw color, reminiscent of sunshine. A persistent, rocky white head forms, leaving delicate lacing on the glass as it recedes. Turbidity is a cardinal sin for this style; it should be strikingly transparent.
• Aroma: The nose is subtle and inviting. Expect a clean, bready-to-cracker-like malt character from the Pilsner malt, gently supported by a faint whisper of noble hop spiciness or floral notes (from the Hallertau). There should be absolutely no fruity esters, diacetyl, or solventy alcohol notes—just pure fermentation cleanliness.
• Mouthfeel: This beer is designed to be highly refreshing. It boasts a light body, a crisp texture, and lively carbonation (2.5-2.7 volumes CO2) that tingles on the tongue. It finishes dry, encouraging another sip, without any cloying sweetness or heavy mouthfeel.
• Flavor: The flavor mirrors the aroma with a harmonious balance. A gentle, sweet maltiness leads, quickly transitioning to a mild, balanced bitterness that cleanses the palate. The absence of distracting flavors allows the subtle breadiness and faint noble hop character to shine through. The finish is remarkably clean, dry, and invigorating, making it a perfect session beer.

Why use flaked maize in this clone?

Flaked maize (corn) serves several critical purposes in replicating the authentic character of an Italian pale lager like Birra Moretti. Firstly, it lightens the body significantly, contributing to the beer’s crisp and refreshing mouthfeel without diluting flavor. Secondly, it helps achieve that brilliant pale straw color, as it contains no melanoidins. Thirdly, it dries out the beer, enhancing fermentability, which is crucial for the very low final gravity typical of this style. Finally, historically, adjuncts like corn were often used in European lagers to make them more accessible and palatable as everyday thirst quenchers.

Is a diacetyl rest truly necessary for a clean lager?

Absolutely, yes. A diacetyl rest is not merely optional; it is a fundamental step for producing a truly clean lager. During the initial, colder phase of lager fermentation, yeast produces a precursor to diacetyl. If the beer is crash-cooled too soon, the yeast can’t clean up these compounds, leading to an unmistakable buttery or butterscotch off-flavor (diacetyl). By raising the temperature to 18°C (64°F) for 2-3 days, you encourage the yeast to become active again, reabsorbing these precursors and converting them into flavor-neutral compounds. Skipping this step is a common mistake I see among novice lager brewers, and it inevitably leads to a less refined beer.

What’s the optimal carbonation level for a Birra Moretti clone?

For a crisp, refreshing Italian pale lager, I find an optimal carbonation level to be between 2.5 and 2.7 volumes of CO2. This range provides a lively effervescence that enhances the beer’s crispness and light body without being overly fizzy. Below this, the beer can feel flat and heavy; above it, it might become too carbonic, masking the subtle malt and hop notes. Achieving this precisely requires either a well-calibrated CO2 regulator and temperature control for kegging or accurate priming sugar calculations for bottling.