Reusable coffee capsules offer more control, better coffee, and far less waste than disposable pods. However, they also require a bit more understanding than simply pressing a button. Most negative experiences with reusable capsules are not caused by the capsule itself, but by small, correctable mistakes in preparation, grind size, filling, or brewing technique.

This guide is intentionally detailed. It is designed to help you avoid frustration, improve taste, protect your coffee machine, and get consistently excellent results from your reusable MyCoffeestar capsules.

Mistake #1: Using the Wrong Grind Size (The Most Common Problem)

Grind size is the single most important factor when using reusable coffee capsules, and it is also the source of most user frustration. Unlike disposable aluminum capsules, reusable capsules give you control over extraction — but that also means responsibility.

When water flows through coffee, it needs the right balance of resistance. Too much resistance blocks the flow, too little resistance lets the water rush through without extracting enough flavor. Grind size controls exactly this balance.

When the grind is too fine

If the coffee is ground too fine, the particles pack very tightly together. Water struggles to pass through the coffee bed, pressure builds up, and the machine may stop the brewing process early as a safety measure. In many cases, only a few drops of coffee come out, or the cup is noticeably underfilled. Sometimes, fine particles are forced through the capsule and end up in the cup.

This situation is often mistaken for a machine defect, but in practice it is almost always grind-related.

The solution is simple but requires small adjustments. Grind the coffee slightly coarser, avoid compressing it too much, and allow the water to flow naturally. Even a small change in grind size can dramatically improve extraction.

When the grind is too coarse

If the grind is too coarse, the opposite problem occurs. Water flows through the coffee bed too quickly and does not have enough contact time to extract sweetness, body, and aroma. The result is a cup of coffee that tastes watery, sour, and thin, with little structure or mouthfeel.

In this case, the solution is to gradually grind finer. Adjust in small steps and taste after each change. The goal is a steady, even flow — not too fast and not too slow.

Best practice: two grind sizes

In everyday use, it makes sense to work with two grind sizes. For espresso and short coffees, a slightly finer grind works best. For longer coffees or lungos, a slightly coarser grind allows enough water to pass through without over-extracting the coffee. This approach gives you much more consistency and control.

Mistake #2: Using Pre-Ground Coffee

Pre-ground coffee can work with reusable capsules, but it comes with certain limitations. The main challenge is that the grind size is fixed. This means you cannot easily adapt it to different machines, coffee styles, or personal taste preferences.

If the grind is slightly too fine, water flow can be restricted. If it is slightly too coarse, the coffee may taste thin or sour. With pre-ground coffee, your ability to correct this is limited.

That said, high-quality, well-balanced pre-ground coffee can deliver very good results, especially when it is specifically designed for espresso or capsule use. The most important factor is consistency and freshness.

Whenever possible, store pre-ground coffee airtight and use it within a short time after opening to preserve aroma and flavor.

Mistake #3: Not Grinding Fresh

Freshness plays a much bigger role in reusable capsules than many people expect. Coffee contains hundreds of volatile aroma compounds that evaporate quickly once the beans are ground. Even high-quality coffee can taste dull and lifeless if it has been ground hours or days before brewing.

When coffee is not ground fresh, extraction becomes less predictable. Crema is weaker, aromas are muted, and the cup often lacks depth.

Grinding only the amount you need, directly before brewing, ensures maximum aroma, better extraction, and a more balanced cup. This is one of the simplest changes with the biggest impact.

Mistake #4: Overfilling the Capsule

Overfilling is a common mistake, especially when users try to compensate for weak coffee. Adding too much coffee reduces the space inside the capsule that water needs to move and expand during extraction.

When the capsule is overfilled, water flow becomes restricted, pressure increases, and the machine may stop the brewing process early. Even if coffee comes out, extraction is often uneven.

The correct approach is to fill the capsule to the recommended level and leave enough space for the coffee to bloom and expand. More coffee does not automatically mean stronger coffee — proper extraction does.

Mistake #7: Ignoring Coffee Dose Consistency

Changing the amount of coffee between brews leads to inconsistent results.

Solution:

  • Use a scale or consistent scoop
  • Repeat the same dose

Mistake #8: Skipping Regular Capsule Cleaning

Old oils and residues negatively affect taste.

Solution:

  • Rinse after each use
  • Deep clean regularly

Mistake #9: Expecting Identical Results to Disposable Pods

Reusable capsules offer more control but require adjustment.

Mindset shift:

  • Think of it as manual brewing, not automation

Mistake #10: Blaming the Capsule Instead of Adjusting Variables

Most issues are caused by grind size, dose, or compression.

Solution: Change one variable at a time.

Why a Coffee Grinder Is the Best Investment

A grinder allows:

  • Precise grind control
  • Fresh coffee
  • Better taste

Espresso vs. Lungo: Understanding the Difference in Reusable Capsules

One of the most common sources of confusion when using reusable capsules is the difference between espresso and lungo. While both are brewed with the same machine, they require different settings and expectations.

Espresso is brewed with a smaller amount of water and a shorter extraction time. To work well in reusable capsules, espresso typically benefits from a slightly finer grind, which creates enough resistance for proper extraction and a full-bodied result.

Lungo, on the other hand, uses significantly more water. If the grind is too fine, the machine may struggle to push the larger water volume through the capsule. For this reason, lungo generally requires a slightly coarser grind to maintain a steady flow without overloading the system.

Using the same grind size for both espresso and lungo often leads to compromise. Espresso may taste acceptable, but lungo can become bitter, overly strong, or cause the machine to stop early. Alternatively, a grind optimized for lungo may result in under-extracted espresso.

For best results, we recommend thinking of espresso and lungo as two distinct brewing styles. Adjusting the grind size accordingly leads to better taste, more reliable extraction, and a much more enjoyable coffee experience overall.

Final Thoughts

Reusable capsules reward patience and understanding. Once dialed in, they consistently outperform disposable pods in taste, sustainability, and cost.

Small adjustments make a big difference.

MyCoffeestar reusable capsules are designed to work perfectly — when the fundamentals are right.