What Happens If You Grind Coffee Too Fine?

coffee grinds

by Matt Gibson

The very first step in the process of determining how your coffee is going to taste is the way the coffee is ground and the size of the grinds you create. The most perfect beans, the ideal roast, pure filtered water and a high dollar coffee maker, can all combine to make bad coffee if the grind is mishandled. On the other hand, some mediocre beans, tap water, and a standard electric drip coffee maker can combine to make an excellent cup of coffee if the grind is well executed. 

The goal when grinding coffee is to break down the beans so that the flavor, aroma, oils, and caffeine content can be extracted when brewing. Grinding your coffee beans gives them a larger surface area, allowing your hot water to make contact with more coffee during extraction. No matter what kind of coffee you are brewing, there are a few general rules to follow when grinding coffee: 

  1. Wait until you are ready to brew your coffee to grind your beans to achieve maximum freshness. 
  2. Use a nice coffee grinder and grind your beans to the appropriate size grounds for the type of coffee you are making. 
  3. Use a clean grinder with sharp blades to grind your coffee beans. 
  4. If you are going for a fine grind, let your grinder rest for a few seconds here and there so that the blades don’t get too hot and burn your coffee grinds. The longer you use your grinder, the hotter the blades will get, so the longer, and more frequent your rests should be. 

Perfecting your coffee grinding technique can make all the difference in the quality of coffee you brew. Knowing the right size grinds for the right type of brew is essential, but it doesn’t make much difference if you struggle to get your grinds to the size you want. Investing in a good coffee grinder and learning how to use it properly is your key to perfecting your brewing technique. 

In this article, we’ll cover all the essentials of coffee grinding, from what occurs when your grind is too fine, too coarse, and just right, to what size grinds are the best for specific types of coffee. We’ll discuss the reasons why grind size matters so much and how it affects the taste of your coffee, and we’ll briefly touch on what you should look for when purchasing a coffee grinder. By the time you reach the end of this article, you should know the scoop on how to perfect your coffee grinding skills. Then it’s time to get your hands involved, and practice putting your new grinding knowledge into action. 

When Coffee Is Ground Too Fine 

When coffee is too finely ground, it gets over-extracted when brewing, which leads to a very bitter brew. Over-extracted coffee can also be hollow, or tasteless, but usually it is just plain bitter. Coffee beans that have been ground too fine for regular coffee might not be a complete waste, however, as you need a finer grind for making espresso. Turkish coffee also calls for a finer grind. 

So if you happen to have the proper equipment for making espresso or Turkish coffee, you can use your overly ground grounds to make specialty coffees instead of just tossing them in the garbage. However, make sure that the grinds are uniformly ground, no matter what type of coffee you are making. If you have an uneven grind, you will have an uneven brew, and uneven grounds make terrible coffee, no matter what form you brew it in. 

When Coffee Is Ground Too Coarse 

When coffee is ground too coarsely, it gets under-extracted during the brewing process. Under extraction can be just as bad as over extraction. Under-extracted coffee can taste sour, acidic, and even salty. Coffee beans that have been ground too coarsely may not be something you should just toss in the trash right away. Firstly, they might be saveable, as you can try re-grinding them in a different grinder to see if you can get them down to the right size. 

Alternatively, you could use your overly-coarse coffee grounds to make cold brew coffee, as long as the grounds are uniformly sized. Though your oversized grinds are not going to work in espresso or in a pour over or electric drip coffee maker, they might work in a french press, which fully submerges the grounds in hot water, and can typically handle coarse grinds, as long as the size is uniform.  

When Coffee Is Ground Just Right 

So what is the perfect size for coffee grounds? Unfortunately, there is no one particular size that is just right for all coffee types. There is a perfect size for each specific brew type, however, which means there are quite a few sizes that are just right, depending on the way you are making your coffee. So, in terms of the perfect grind, the best thing to shoot for is uniformity. 

Ideally, no matter what grind size you are shooting for, there will be little to no variation in the size of the grinds when you are done. This is harder to achieve than you might think, especially if you are using a blade based grinder. Blade-based grinders are terrible at grinding coffee beans uniformly. They also tend to get way too hot, which can burn your coffee grinds before you get a chance to brew them. 

What to Look For in a Coffee Grinder (Burr Grinders) 

For true uniformity, and less friction and heat, you need a good conical burr grinder. A burr grinder rotates your beans and uses pressure, applied equally to all of the beans in the grinder, crushing them into near perfect consistency. The burr grinder also works slowly, with no friction, which results in a precise and consistent grind that never scorches your beans in the process. With a burr grinder, every time you grind your coffee, you can get it just right.  

Why Grind Size Matters 

There is not one ground size that fits all applications when it comes to coffee grinding. Instead, there are different ground sizes that work for different types of brewing. Some brewing methods can make a good cup of coffee out of several different grind sizes, while others need a specific size to brew correctly. Below, we listed each grind size and linked them to the brewing method that is perfect for the grind. Use this chart when deciding how finely to grind your coffee beans for whatever brewing method you are wanting to use. 

Extra Fine Grounds – Extra fine grounds are really only good for Turkish coffee. Though espresso calls for fine ground coffee, there is such a thing as too fine for your espresso machine. If you’ve overdone it and ground your coffee beans into a fine powder, there is only one way to put them to use, and that’s by using the turkish brewing method. To learn how to make authentic Turkish coffee, click here.

Fine Grounds – Finely ground coffee is perfect for espresso makers, both the standard pressure machines and stovetop models. Fine grounds also work for Aeropress devices when brewing with a one minute extraction time. 

Medium-Fine Grounds – Medium-fine grounds are well suited to pour over coffee brewing using a cone-shaped device, as well as Aeropress coffee makers when brewing using a two to three minute extraction. 

Medium Grounds – Medium is the most common coffee ground size. This is the size that you typically see in pre ground roasts. Medium grounds are perfect for electric drip coffee makers, cone-shaped pour overs, Aeropress devices using greater than three minute extraction time, and siphon coffee brewing. 

Medium-Coarse Grounds – Medium-coarse is slightly bigger than what you are used to seeing in a can of pre-ground coffee. This size of grounds is perfect for Clever Dripper machines, Chemex pour over devices, and Cafe Solo coffee makers. 

Coarse Grounds – Grounds on the coarser side work well in the French press, in percolator machines, and when brewing for coffee cuppings (fancy coffee tasting parties). 

Extra Coarse Grounds – Extra coarse grounds are too big for most coffee makers, but they do work well when making cold brew coffee, as the much longer extraction time can get plenty of flavor, caffeine, and oils out of even the largest grinds of coffee. Extra coarse grounds also work for cowboy coffee, if you ever find yourself on the trail. 

Most people have a preferred brewing method, such as pour over, French press, or electric drip brewers. If you make coffee the same way pretty much every time you make it, you only need to master making one of the different grind sizes. With the right grinder and a little practice, you can get the hang of grinding your own coffee very easily, and will be able to quickly grind your beans into a uniform size grind that is perfect for your brewing style of choice. Practice makes perfect. 

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