As an espresso enthusiast, brewing an under-extracted espresso can be a frustrating experience, but there are ways to fix it. Here’s a refined guide based on my personal journey.

Understanding Under-Extraction

Under-extraction happens when water flows too quickly through the grounds, leading to sour, thin, and weak espresso. It’s important to tweak multiple factors to correct it, and I’ll walk you through the steps that worked for me.

Fine-Tune the Grind Size

The grind size directly affects how water interacts with the coffee. If the grind is too coarse, the water will flow through quickly, leading to under-extraction. In my case, adjusting the grinder to a finer setting made a significant difference. A finer grind increases the surface area of the coffee, allowing the water to extract more flavors.

Pro Tip: Make small adjustments to your grinder, moving one notch finer at a time until the espresso reaches a rich, balanced flavor.

Adjust Your Brew Ratio

A standard espresso brew ratio is typically 1:2, meaning 18 grams of coffee yields around 36 grams of espresso. When I noticed my espresso tasted under-extracted, tweaking this ratio helped. Adding a little more coffee or reducing the amount of water made a big difference.

My Advice: Using a scale to measure your coffee and water ensures consistency, which is crucial for getting a balanced shot every time.

Optimize Water Temperature

Espresso requires water between 195°F and 205°F (90°C to 96°C) for optimal extraction. I found that when my machine brewed at a cooler temperature, the espresso tasted sour. Giving the machine extra time to fully warm up improved the flavor significantly. If your machine has adjustable temperature controls, try raising it slightly for better extraction.

Fine-Tune Tamping Pressure

When I first started, I didn’t realize how important consistent tamping pressure was. If you tamp too lightly, the water will flow too fast, causing under-extraction. Aim for around 30 pounds of pressure to ensure the coffee is evenly compressed, allowing the water to pass through at the right rate.

Pro Tip: Practice tamping on a scale to get a feel for the correct pressure. This ensures you’re tamping evenly every time.

Adjust the Shot Time

Shot timing is critical in getting a balanced espresso. Ideally, a shot should pull between 25 and 30 seconds. When my shots were pulling too quickly, I adjusted by grinding finer and increasing the coffee dose, which slowed down the extraction. Keeping a close eye on the timer has helped me achieve consistently better results.

Use Fresh Coffee Beans

I learned the hard way that stale beans lead to poor extraction. Freshly roasted beans—ideally within two weeks of roasting—contain more oils and soluble compounds that contribute to better flavor extraction. Now, I make sure to use only fresh beans, and the difference in taste is remarkable.

Conclusion: Achieving the Perfect Shot

Fixing under-extracted espresso is all about fine-tuning key factors like grind size, brew ratio, water temperature, tamping pressure, and shot timing. Through small adjustments and regular practice, I’ve learned how to consistently pull rich, balanced espresso shots that rival my favorite café. With patience and attention to detail, you’ll master the process too—happy brewing!