Did you ever have a cup of coffee in the morning that was bitter or sour? Odds are it wasn’t the beans that were bad, but rather grind size. The grind size affects rate at which water can extracts the flavor out of the bean. Right and it will be complex and sweet. Wrong and it’s going to be harsh and unpleasant.
As you can see on chart, the grind size that’s appropriate depends on what brew method we’re using. Why? Grind size affects surface area. More surface area mean more flavor extraction in less time. That’s why espresso employs a fine grind, it spends only twenty seconds in contact with water. But if you pour your espresso into a French press using that fine grind, the water’s going to hang out there for four minutes. The coffee will be over-extracted, making it bitter and harsh. Grind size isn’t just about texture… It’s a way of managing time.
How to Choose the Right Grind Size for Your Coffee
For pour-overs, you’ll want a grind about the size of table salt. A medium-fine grind. It should take two or three minutes for water to make its way through filter. The grounds will be large enough to avoid uneven water flow while also revealing fruit notes and acidity. Taste your brew: if you find yourself with sour-tasting coffee that’s drained too fast, your grind is too coarse. If it takes forever to drain and you’re left with dry-tasting coffee, the grind’s too fine. One setting won’t work every time; adjust to match each batch of bean.
For cold brew, you want an extra coarse grind that looks like cracked pepper or even sea salt. Why? Because if grounds are too small they’ll be over extracted during longer brewing period (twelve (twenty-four hours)). With cold water and slow extraction, it’s all about time. A fine grind will result in bitterness as it sits and soaks for such a long period of time. The bigger particles stays together and create a smooth concentrate with hints of vanilla and chocolate.
Second is the grinder. The grinder is just as important as its size setting. Chopping (blade) grinders cut bean unevenly, resulting in some small particles (dust) and larger ones. When brewed, this mixture extract too slowly for some particles but too quickly than others, muddying the flavor. Crushing (burr) grinders evenly grind the bean between two adult-sized sofa, resulting in equal particles. Equal particles will be extracted equally, resulting in a cleaner tasting cup. If you’re looking for consistency, go with a burr grinder.
Quality matters too. Within half an hour after being ground, coffee begin to lose its aromatic compounds. When left on store shelves, pre-ground coffee will continue to oxidize and lose flavor over time (months). Keeping these volatile oils intact requires that you grind just prior to brewing. To further delay oxidation, keep whole beans in a cool, dry place based off your kitchen cabinet, away from sunlight (an opaque, airtight container works best). Avoid freezing unless you are portioning the beans tightly, as they’ll get damaged by condensation once warmed.
The speed of extraction also vary by roast level. The denser the roast (light), the longer it takes to extract. The more brittle and porous the roast (dark), the quicker it extracts. So if you go from a light roast to a dark roast, go up one grind size to counteract this change. Use chart recommendations as a starting point for grind size, but dial in according to your taste buds. You’ll notice something is wrong long before you can taste it. Listen to your nose! And make the ideal cup one even particle at a time.
You should of tried different roast levels too. Actualy, you could of used a moddern grinder. It makes the coffee more comfortablly delicious.