How to Dial In Espresso with a 98mm Flat Burr Coffee Grinder: A Step-by-Step Guide
Dialing in espresso is one of the most valuable skills a home barista can learn. Even with freshly roasted beans and a capable espresso machine, the final cup quality depends heavily on how accurately your grinder is adjusted. A small change in grind size can transform an under-extracted, sour shot into a balanced espresso with greater sweetness and clarity.
A 98mm flat burr coffee grinder makes this process more predictable by producing a more consistent particle distribution and reducing grind retention. Combined with a thoughtful workflow, it allows you to fine-tune extraction with fewer adjustments and achieve repeatable results every day.
This guide explains how to dial in espresso step by step, from selecting fresh coffee beans to interpreting extraction time and taste. Whether you're new to home espresso or upgrading to a premium flat burr grinder, these techniques will help you build confidence and brew consistently better coffee.
What Does 'Dialing In Espresso' Mean?
Dialing in espresso is the process of adjusting your grinder and brewing recipe until the coffee extracts with the desired flavor, body, and balance. Rather than chasing a specific grind setting, you're finding the combination of grind size, dose, yield, and extraction time that best suits a particular coffee.
Every bag of coffee behaves differently. Factors such as origin, roast level, bean density, and freshness influence how quickly water flows through the coffee puck. This is why even experienced baristas make small adjustments whenever they open a new bag of beans.
The Four Variables You Should Control
- Dose: The amount of coffee placed in the portafilter.
- Grind Size: Determines how quickly water passes through the coffee bed.
- Yield: The amount of espresso produced in the cup.
- Extraction Time: The total brewing time from pump start to finish.
These variables work together. Changing only one factor at a time makes it much easier to understand how each adjustment influences flavor. This systematic approach is recommended by many professional trainers and organizations, including the Specialty Coffee Association (SCA).
Why a 98mm Flat Burr Grinder Makes Dialing In Easier
Not all grinders respond equally to fine adjustments. Larger flat burrs generally produce a more uniform particle distribution, making extraction easier to control. This consistency reduces the number of variables you need to manage during the dialing-in process.
A high-quality 98mm flat burr coffee grinder is designed to minimize grind retention while maintaining excellent burr alignment. The result is cleaner flavor separation, more repeatable grind settings, and fewer surprises when switching between different coffees.
More Uniform Particle Distribution
Espresso extraction depends on evenly sized coffee particles. When particle distribution becomes more consistent, water flows more uniformly through the puck, reducing channeling and producing sweeter, more balanced espresso.
Lower Retention Means Better Consistency
Coffee left inside the grinder after each use gradually becomes stale. When those old grounds mix with fresh coffee, dialing in becomes less predictable. Low-retention grinders help ensure every shot starts with freshly ground coffee, making adjustments more reliable.
More Precise Grind Adjustments
Premium flat burr grinders often feature stepless adjustment mechanisms that allow very small changes in grind size. These micro-adjustments become especially valuable when you're trying to perfect espresso recipes within just a few seconds of extraction time.
Step 1: Start with Fresh Coffee Beans
Before adjusting your grinder, make sure your coffee is suitable for dialing in. Freshly roasted beans provide more stable extraction and a richer flavor profile than coffee that has been sitting open for several weeks.
Choose Beans Within the Ideal Freshness Window
Most specialty espresso coffees perform best between seven and twenty-eight days after roasting. During this period, excess carbon dioxide has largely escaped while the aromatic compounds responsible for sweetness and complexity remain well preserved.
Store Coffee Properly
Exposure to oxygen, moisture, heat, and light accelerates coffee degradation. Store beans in an airtight container at room temperature and avoid leaving large quantities inside a grinder hopper for extended periods.
Weigh Every Dose
Consistency starts with accuracy. Using a digital scale to weigh each dose ensures that every adjustment is based on repeatable conditions. Even a difference of half a gram can noticeably change extraction time and flavor.
This is one reason many experienced home baristas pair fresh beans with a single-dose workflow. Measuring each dose individually reduces waste, simplifies recipe testing, and makes grinder adjustments far easier to evaluate.
Step 2: Set Your Initial Grind Size
Once you've prepared fresh coffee beans and weighed your dose, it's time to establish a starting point. Although every grinder is different, beginning with a proven espresso recipe allows you to make logical adjustments instead of guessing.
A common starting recipe for medium-roasted espresso is 18 grams of coffee in, 36 grams of espresso out, with a target extraction time of approximately 25–30 seconds. This recipe is not a strict rule, but it provides a reliable reference when dialing in a new coffee.
Recommended Starting Recipe
- Dose: 18g
- Yield: 36g
- Brew Ratio: 1:2
- Target Time: 25–30 seconds
- Water Temperature: 92–94°C (198–201°F)
Start with this recipe before making any adjustments. Changing multiple variables simultaneously makes it difficult to identify what actually improved or worsened the shot.
Step 3: Adjust Based on Extraction Time
Extraction time provides valuable feedback, but it should never be your only decision-making tool. Instead, use it as a guide alongside taste and visual observation. Small grind adjustments are usually enough to bring a shot back into balance.
Espresso Troubleshooting Guide
| What You Observe | Likely Cause | Recommended Adjustment |
|---|---|---|
| Shot finishes in under 20 seconds | Grind too coarse | Grind finer |
| Shot exceeds 35 seconds | Grind too fine | Grind coarser |
| Sour, thin flavor | Under-extraction | Slightly finer grind |
| Dry, bitter finish | Over-extraction | Slightly coarser grind |
Resist the temptation to make large adjustments. One small grind change followed by another test shot produces much more reliable results than dramatic changes that introduce additional variables.
How Different Roast Levels Affect Dialing In Espresso
Roast level has a significant influence on espresso extraction, which means there is no universal grind setting that works for every coffee. Beans roasted to different levels vary in density, solubility, and carbon dioxide content, requiring different approaches when dialing in. Understanding these differences allows you to make faster, more accurate grinder adjustments.
Light Roast Espresso
Light roasted coffees are generally denser and less soluble than darker roasts. Water passes through them less efficiently, so they often require a finer grind and slightly longer extraction to fully develop sweetness and complexity.
Expect brighter acidity, floral aromas, and pronounced fruit notes. If your shot tastes sharp, grassy, or overly sour, it may be under-extracted. Grinding slightly finer usually produces a more balanced cup.
Medium Roast Espresso
Medium roasts are typically the easiest coffees to dial in because they offer a balance between sweetness, acidity, and body. Most traditional espresso recipes—such as an 18g dose with a 1:2 brew ratio—perform well with medium roasted beans.
Small grind adjustments are usually enough to optimize flavor. When everything is working correctly, expect caramel sweetness, balanced acidity, and a smooth, syrupy mouthfeel.
Dark Roast Espresso
Dark roasted beans are more soluble because they have undergone greater structural breakdown during roasting. They usually require a slightly coarser grind and often extract faster than lighter coffees.
Grinding too fine can easily lead to over-extraction, creating excessive bitterness and dryness. If the finish feels harsh or smoky, try making a slightly coarser adjustment while maintaining the same brew ratio.
Quick Reference Guide
| Roast Level | Recommended Grind | Flavor Goal |
|---|---|---|
| Light Roast | Slightly Finer | Sweetness, clarity, balanced acidity |
| Medium Roast | Medium | Balance, sweetness, body |
| Dark Roast | Slightly Coarser | Chocolate notes, smooth finish, reduced bitterness |
Regardless of roast level, make only one adjustment at a time and evaluate the flavor before changing another variable. A consistent grinder with low retention allows these small changes to produce more predictable results, making the dialing-in process faster and easier.
Taste Before You Adjust Again
Numbers provide consistency, but taste determines success. Two espresso shots with nearly identical extraction times can still taste very different depending on bean origin, roast level, and burr geometry.
Evaluate Sweetness First
A well-dialed espresso should present natural sweetness before bitterness. If sweetness is missing, the shot often needs further adjustment even if the extraction time appears correct.
Look for Balance
Acidity should be bright but pleasant, bitterness should support the finish rather than dominate it, and body should feel smooth instead of harsh or watery. Developing these tasting habits is often more valuable than chasing exact numbers.
The Specialty Coffee Association emphasizes sensory evaluation alongside brewing parameters because flavor ultimately determines whether an espresso recipe is successful.
Common Dialing-In Mistakes
Changing Multiple Variables at Once
Adjusting dose, grind size, yield, and temperature simultaneously makes it impossible to identify which change affected the result. Modify one variable at a time.
Using Old Coffee Beans
Coffee that has lost freshness produces inconsistent extractions regardless of grinder quality. Always begin with recently roasted beans whenever possible.
Ignoring Grinder Cleanliness
Retained coffee oils and old grounds influence flavor and reduce consistency. Regular cleaning keeps burr performance stable and preserves cup quality.
Skipping Distribution
Uneven grounds increase the likelihood of channeling. Simple distribution techniques such as WDT can significantly improve extraction uniformity before tamping.
Build a Repeatable Home Espresso Workflow
Dialing in becomes much easier when every step follows the same routine. Consistency removes unnecessary variables and allows your grinder adjustments to produce predictable results.
- Store beans in an airtight container.
- Weigh each coffee dose accurately.
- Grind immediately before brewing.
- Distribute grounds evenly using WDT if needed.
- Tamp consistently with level pressure.
- Record extraction time and yield.
- Taste the espresso before making further adjustments.
If you're looking for a balanced upgrade that combines excellent grind consistency with low retention, an 80mm flat burr coffee grinder is an excellent option for many home baristas. Those seeking maximum grinding speed and commercial-level consistency may prefer a 120mm flat burr coffee grinder, especially for high-volume espresso preparation.
Final Thoughts
Learning to dial in espresso is a skill that improves with practice rather than expensive equipment alone. By controlling one variable at a time, using fresh coffee, and evaluating flavor carefully, you can achieve remarkably consistent results at home.
A well-designed 98mm flat burr grinder makes this process easier by delivering consistent particle distribution, low grind retention, and precise grind adjustments. Combined with a repeatable workflow, it allows you to spend less time troubleshooting and more time enjoying balanced, flavorful espresso.
Frequently Asked Questions
How long should an espresso shot take?
Most espresso recipes target approximately 25–30 seconds, although the ideal extraction time depends on the coffee and desired flavor profile.
Should I adjust grind size every day?
Yes. Changes in coffee freshness, humidity, and bean origin often require small daily grind adjustments to maintain consistent espresso quality.
Why is my espresso still sour after dialing in?
Sour espresso usually indicates under-extraction. Try grinding slightly finer or extending extraction while keeping other variables consistent.
Does a 98mm flat burr grinder improve espresso consistency?
In many cases, yes. Larger flat burrs generally produce more uniform particle distribution and lower retention, making espresso easier to dial in consistently.