Dialing In Your Brew: Adjusting Grind Size for Perfect Coffee Strength

Question: How can I adjust my grind size if my coffee is consistently coming out too weak or too strong?

The quest for the perfect cup of coffee often involves a delicate dance of variables, but one of the most fundamental adjustments a home barista can make is to the grind size. When your coffee consistently tastes too weak or too strong, altering your grinder’s setting is likely the most effective solution.

Understanding Extraction and Grind Size

The strength of your coffee is directly related to how much soluble material has been extracted from the coffee grounds into the water. Finer grinds have a larger surface area exposed to water, allowing for faster and more efficient extraction. Conversely, coarser grinds have less surface area, leading to slower and less complete extraction. This relationship is central to achieving a balanced flavor profile.

When Your Coffee is Too Weak

A weak, watery, or underdeveloped cup of coffee is a classic sign of under-extraction. This means that not enough of the desirable flavor compounds have been dissolved from the coffee grounds into the water. When this is the case, the most logical adjustment is to grind your coffee finer [5]. A finer grind increases the contact time between the water and the coffee particles, allowing for a more thorough extraction of solubles and a fuller-bodied, more flavorful brew.

When Your Coffee is Too Strong

On the other hand, if your coffee tastes overwhelmingly bitter, harsh, or astringent, it’s likely suffering from over-extraction. This occurs when too many compounds, including undesirable bitter ones, have been leached into the water. To combat this, you should grind your coffee coarser [5]. A coarser grind will reduce the surface area and slow down the extraction process, preventing the over-extraction of bitter elements and leading to a smoother, more balanced taste. The goal is to extract the desirable sweetness and aromatics without pulling out the excessive bitterness [4].

Beyond Grind Size: Other Influences

While grind size is paramount, it’s important to acknowledge that other factors can influence extraction and perceived strength. For espresso, for instance, flow rate is noted as having a significant influence on the total mass of components extracted [5]. Similarly, water temperature and the coffee-to-water ratio play crucial roles [3, 5]. However, for most brewing methods where the primary variable to control is strength, grind size remains the most accessible and impactful adjustment. The type of coffee beans used, whether Arabica or Robusta, can also contribute to the final flavor profile, with Arabica beans often offering more complex aromatic notes [4].

A Note on Consistency

Achieving consistent results requires precision. Ensure your grinder produces a uniform particle size for each setting. Uneven grinds can lead to a mix of under- and over-extracted coffee within the same brew, resulting in an unbalanced and unpredictable cup. Regularly cleaning your grinder can also prevent old coffee oils from affecting the flavor of your fresh grounds.

In conclusion, when faced with a coffee that’s consistently too weak or too strong, your grinder is your most powerful tool. By understanding the relationship between particle size and extraction, you can confidently adjust your grind to unlock the full potential of your coffee beans and consistently achieve a delicious, well-balanced brew.

References

[1] — Ernesto Illy, Luciano Navarini — Neglected Food Bubbles: The Espresso Coffee Foam. — 2011-Sep — https://pubmed.ncbi.nlm.nih.gov/21892345/ [2] — Magdalena Zdanowicz, Marta Rokosa, Magdalena Pieczykolan, Adrian Krzysztof Antosik, Katarzyna Skórczewska — Biocomposites Based on Wheat Flour with Urea-Based Eutectic Plasticizer and Spent Coffee Grounds: Preparation, Physicochemical Characterization, and Study of Their Influence on Plant Growth. — 2024-Mar-06 — https://pubmed.ncbi.nlm.nih.gov/38473683/ [3] — Katarína Poláková, Alica Bobková, Alžbeta Demianová, Marek Bobko, Judita Lidiková, Lukáš Jurčaga, Ľubomír Belej, Andrea Mesárošová, Melina Korčok, Tomáš Tóth — Quality Attributes and Sensory Acceptance of Different Botanical Coffee Co-Products. — 2023-Jul-11 — https://pubmed.ncbi.nlm.nih.gov/37509767/ [4] — Rongsuo Hu, Fei Xu, Liyan Zhao, Wenjiang Dong, Xingyuan Xiao, Xiao Chen — Comparative Evaluation of Flavor and Sensory Quality of Coffee Pulp Wines. — 2024-Jun-27 — https://pubmed.ncbi.nlm.nih.gov/38999011/ [5] — Benedikt K L Schmieder, Verena B Pannusch, Lara Vannieuwenhuyse, Heiko Briesen, Mirjana Minceva — Influence of Flow Rate, Particle Size, and Temperature on Espresso Extraction Kinetics. — 2023-Jul-28 — https://pubmed.ncbi.nlm.nih.gov/37569140/ [6] — Ewa Olechno, Anna Puścion-Jakubik, Katarzyna Socha, Małgorzata Elżbieta Zujko — Coffee Brews: Are They a Source of Macroelements in Human Nutrition? — 2021-Jun-09 — https://pubmed.ncbi.nlm.nih.gov/34207680/