Grind your Costa Rican coffee medium-fine for AeroPress, about the texture of table salt. That is the starting point both the National Coffee Association and AeroPress itself suggest for this brewer, and it works especially well for Costa Rican beans.
Costa Rican coffee is often bright, clean, and acidic, with citrus and sweet notes, according to Atlas Coffee Club’s guide to the origin. A grind that is too fine can push those flavors toward bitterness and harshness. A grind that is too coarse can taste thin and sour.
The Short Answer: Medium-Fine
Set your grinder to medium-fine, meaning slightly finer than drip coffee and quite a bit coarser than espresso. The National Coffee Association’s AeroPress brewing guide treats this as the standard setting for the method.
A helpful physical check: the grounds should feel like table salt between your fingers. Pressing should take steady effort, but you should not have to force the plunger down.
A burr grinder makes this consistency much easier to hit than a blade grinder. A blade grinder chops beans into uneven pieces, so some particles extract more than others no matter what setting you aim for.
- Key Specifications:
- Burr type: conical or flat steel/ceramic burrs
- Setting: medium-fine, roughly 10 to 20 clicks from fully closed on most hand grinders
- Consistency: uniform particles, minimal dust
If you need a reliable option, the Baratza Encore ESP grinder covers everything from AeroPress-fine to French press-coarse. The Timemore C3 Max hand grinder does the same job for less money.
Why Origin Matters Less Than Roast Level
Here is the part most guides skip: your bag’s roast level usually matters more than the fact that the beans came from Costa Rica. Costa Rica grows dense, high-altitude arabica, and its coffee institute classifies top lots as Strictly Hard Bean grown above roughly 1,200 meters.
Dense beans resist extraction, so roast level becomes the practical dial. Light roasts are hardest to extract and often need a finer setting. Darker roasts extract easily and usually need a coarser one.
A washed Costa Rican light roast may taste sour at a grind that tastes perfect for a darker honey-processed lot from the same country. So taste first, then adjust the grinder based on the cup in front of you rather than the flag on the bag.
Your Starting Recipe
Use the table below to set up a standard AeroPress brew before you start adjusting anything.
| Parameter | Starting Point |
| Grind size | Medium-fine (table salt texture) |
| Coffee dose | 15 to 18 g |
| Water | 250 to 300 g |
| Ratio | 1:14 to 1:17 coffee to water |
| Total brew time | About 2 minutes |
Grind a little finer for light-roast Costa Rican beans if the cup seems weak. Grind a little coarser for medium and dark roasts if the cup tastes bitter or dry.
An inexpensive scale removes most of the guesswork here. The 0.1 g digital brewing scale category has solid options under twenty dollars.
Troubleshooting by Taste
A sour or weak cup can indicate under-extraction, which often means the grind is too coarse for the roast. Grind finer or let the brew sit a little longer.
A bitter, hollow, or muddy cup can indicate over-extraction, which often means the grind is too fine. Grind coarser or shorten the brew time.
Change one variable at a time. If you move the grind, the dose, and the temperature together, you will not know which change fixed the cup.
This adjustment pattern is the same skill you would use for grinding Costa Rican coffee for drip brewers, just applied to a shorter immersion brew.
How Grind Interacts With Water Temperature
Water temperature affects extraction alongside grind size, so it deserves one quick note even though grind is the main lever. Lighter roasts generally benefit from hotter water and finer grounds because both increase extraction.
Darker roasts extract faster, so cooler water and a coarser setting tend to keep them from tasting harsh. For a deeper look at the ratio side of this equation for other methods, our page on espresso grinding for Costa Rican beans covers the pressure-based extreme of the same spectrum.
When to Use a Coarser Setting
Some Costa Rican bags, especially natural or anaerobic lots, carry heavy fruit and fermented sweetness. Those flavors can turn sharp and boozy when the grind extracts too aggressively.
If your natural-process Costa Rican tastes boozy or sharply bitter at medium-fine, step one setting coarser. Washed and honey lots, which are the majority of what Costa Rica exports, usually behave well at the baseline medium-fine setting.
The One-Sentence Rule
Start at medium-fine with 15 to 18 g of coffee and about 2 minutes of contact time, then drift finer for light roasts and coarser for dark ones. Trust your palate over any fixed number, because no two grinders mark their dials the same way.
If you also brew these beans cold, the settings change completely, and our guide to Costa Rican cold brew grind size walks through that method separately.
Brew your first cup at medium-fine, table salt texture, with 15 g of coffee to every 225 g of water. Then taste it, and make one small grind adjustment in whatever direction the cup tells you.