You’re Grinding Your Coffee Wrong

What's in a coffee grind? A lot, actually. How you grind your coffee beans is essential to creating a perfect cup of coffee. When mixing ingredients for baking a cake or cookies, the consistency of the batter is incredibly important to the final product. The same logic applies to brewing coffee. Ensuring you have the best grinds for your choice of brewing method is integral to the coffee-making process. 

Of “Coarse” Coffee Grounds Can Be Too Fine!

What happens if the coffee grounds I have are too fine or too coarse for my brewing method, and does it really matter if I have the best grinds intended for my brewing method? What factors go into determining if you need coarse coffee grounds or a finer espresso grind for your coffee beans?

• Contact time
• Extraction rate
• Surface area

Determine Coffee Grind Size Based on Contact Time

This is quite simply the amount of time the coffee grounds are in contact with water during the brewing process. The level of how fine or coarse coffee grounds should be directly relates to the brewing time. An easy rule of thumb for determining the best grind is, the shorter the contact time, the finer the grind.

For example, cold brew coffee can take up to 24 hours to brew, requiring coarse coffee grounds. On the other hand, an espresso grind, named explicitly for making espressos, is a fine grind since it is a relatively quick brewing process.

When most people think of coffee, they typically think of something they can make in a matter of minutes at their home or pick up quickly at their local coffee shop. Brewing methods that you make at home in a pot or using a single-serve machine will typically require a medium grind, as will most chain coffee shops.

What is Coffee Extraction?

The best way to think about extraction is to view it as everything the water takes from the coffee grounds during the brewing process. A longer brewing time means the coffee grounds' flavor and aroma will be in the extraction process for longer. Coarse coffee grounds can withstand an elongated brewing process, while an espresso grind would be too fine to hold up during the cold brew process.

Do you love math? If so, you are probably wondering if there is a formula for determining the extraction rate. You are in luck; you can determine the extraction rate using the formula below:

Extraction Yield % = Brewed Coffee (g) x TDS (%) / Dose (g) 

Extraction Rate in Fine Vs. Coarse Coffee Grounds

An espresso grind is a fine grind and is significantly smaller than a medium or coarse grind. If you were to use coffee beans that have been subjected to the espresso grind during a single-serve or French press brewing process, the coffee grounds would over-extract.

What is over-extraction? Over extraction is when the coffee grounds have been exposed to heated water for too long, resulting in a bitter cup of coffee. Once the coffee grounds have exceeded their intended and recommended extraction time, the natural flavors of the coffee beans are no longer present. Instead, they are surpassed by a bitter flavor and aroma.

On the flip side, if you were to use coarse coffee grounds to make espresso, you would end up with a very weak espresso shot. Since the extraction process for espresso is so much quicker, it does not allow enough time to fully extract the flavors from a coarse ground coffee.

You can think of it in terms of popping popcorn. Kernels that have not been exposed to enough heat either barely pop or do not pop at all. A weak, under-flavored espresso is the exact opposite of what we want.

The Surface Area of Ground Coffee Beans

By increasing the surface area of coffee, you make it significantly more accessible for the water to dissolve the coffee grounds. The finer the grind, the more surface area you create. This is why finer options like espresso grinds work for quicker brewing processes.

The larger the surface area of the coffee grounds, the shorter the required extraction rate. This makes determining the best grinds for your preferred brewing method a little easier to figure out.

5 Types of Coffee Grinds

There are five primary levels of grinding coffee. They range from extra fine to coarsely ground coffee beans. We now know the science behind coffee grounds, but let's get into how we can use that information in our daily coffee routine.

• Extra-Finely Ground Coffee Beans
• Finely Ground Coffee Beans
• Medium Ground Coffee Beans
• Medium-Coarsely Ground Coffee Beans
• Coarsely Ground Coffee Beans 

Extra-Fine Coffee Grounds

The size and consistency of extra-finely ground coffee beans are similar to powdered sugar. This type of grind has a high-speed extraction rate and is only used for two main types of coffee:

• Turkish coffee
• Arabic coffee

Turkish Coffee

This unfiltered process makes for a highly caffeinated cup of coffee. You must use a very small pot with a long handle called a cezve to make Turkish coffee. Traditionally cezve pots were made out of brass or copper. However, more recently, cezve pots have been made from stainless steel, aluminum, or ceramics.

Arabic Coffee

As the name implies, this coffee brewing style was developed and is widely used in Arab countries. The extra-fine coffee grounds are most often mixed with cardamom for a bit of extra flavor.

Arabic coffee is a cultural staple steeped in tradition. It is typically served in a finely adorned cup known as a finjan during family gatherings or when guests come over. 

Finely Ground Coffee/Espresso Grind

Where are my espresso lovers? For a good reason, the fine grind is also known as the espresso grind since it is the necessary and best grind consistency for brewing espresso. The grind size is similar to table salt, and it is easy to find in pre-ground bags at your local grocery store or coffee shop. 

But why do you need your coffee to have the espresso grind when making espresso? It all comes down to the speed of the espresso brewing style. The brewing time for making an espresso is very short. The water is almost immediately pulled through the coffee grounds, so you need the flavor to be extracted as quickly as possible.

Espresso is known for having a strong flavor that people crave when they pour an espresso, and the espresso grind is what guarantees the most robust flavor is produced. Coarse coffee grounds would not be able to replicate the strength of flavor that the espresso grind creates, based on their size and extraction requirements. 

Medium Ground Coffee Beans

This grinding style is the most popular in pre-ground bags and at restaurants and coffee shops that focus on quantity and consistency. Medium ground coffee beans are similar in size to sand or sea salt.

When shopping at your local grocery store for pre-ground coffee beans, this will

be the most common and available option in every brand. For a good reason, since this medium grind, as opposed to the espresso grind or more coarse coffee grounds, has the most diversity regarding the type of brewing methods it works for.

The preferred brewing methods for medium ground coffee beans are drip brewers, single-serve brewing machines, vacuum brewers, and stovetop brewers. Medium ground coffee beans are so versatile that they are recommended for drip brewing, the oldest and cheapest ways to brew coffee; In addition, they are the best grind choice for one of the newer and more widespread ways to brew coffee: the single-serve Keurig machine.

Medium-Coarse Ground Coffee

Coffee beans that are medium-coarse ground have a slightly chunky consistency, similar to rough sand. As the name suggests, this grind level gives coffee beans a consistency between medium and coarse coffee grounds.

This particular coffee grind is not as widely used as the espresso grind or the medium grind, but it serves the purpose as the best grind for several coffee brewing styles. The most popular coffee brewing method that calls for medium-coarse coffee grounds is the Chemex method.

The Chemex method was invented in 1941 by the chemist Dr. Peter Schlumbohm. The Chemex method is a pour-over brewing style that involves using a non-porous glass coffee maker that does not retain or absorb chemical residue or odors. The design and structure of the Chemex method are based on glass lab equipment.

Coarse Coffee Grounds

Coarse coffee grounds resemble kosher salt. This consistency of coffee grounds will contain large, even chunks. French press and cold brew are ideal for when you have coarse coffee grounds. The extended water saturation time period allows for the coffee beans to fully absorb the water, whether it is hot during the French press brewing or cold during the cold brew process. 

The coffee grounds are steeped in water with cold brew coffee for up to 24 hours. Larger, more coarse coffee grounds are the best grind option for this method, as it allows for the gradual extraction of flavor and aromas. If you were to use an espresso grind, for example, the extraction process would happen too quickly; therefore, the remaining time the coffee grounds spent in the water would lead to a very bitter-tasting cup of coffee. Bitter is not better, so make sure you use the best grind of coffee when making French press or cold brew coffee.

Has Your Coffee Gone Bad?

Believe it or not, your coffee can go bad. And it might be sooner than you think. Just as important as having the best grind for your brewing method is keeping your coffee super fresh for as long as possible. Both are important to start your morning off on the right foot. There are two crucial factors in maintaining the freshness of your coffee once you have brought it home.

• Time
• Temperature

How Long Does Ground Coffee Last?

Whether you buy pre-ground coffee beans, grind at home, or have your local store grind for you, once the coffee has been ground, it begins to lose its freshness. The good news is that there is no difference in longevity between an espresso grind or coarse coffee grounds, so don’t worry about this factor when deciding on your best grind options.

It is best to drink it within one to two weeks of grinding to ensure you capture the freshest and most high-quality taste out of your coffee beans. Keep this in mind when purchasing pre-ground coffee; buying in bulk can be appealing but will not guarantee a high-quality coffee experience past the two-week mark.

What is the Best Temperature for Storing Coffee?

There are two schools of thought on where to store your coffee grounds. Some coffee drinkers believe that storing coffee grounds in the freezer is the best way to keep them fresh. However, most coffee connoisseurs agree that coffee grounds are best kept on your countertop at room temperature. Keeping them stored in an airtight container free from dampness is the best way to ensure they last the full two weeks.

So, where did the idea of placing the coffee in the freezer originate from? Freezing coffee is in reference to whole coffee beans that have not been ground yet. The risk of freezer burn is real, so there are a few steps to help ensure this does not happen to your precious coffee beans.

Coffee beans can be stored for up to a month in the freezer if properly taken care of. If you have the option to put them in a deep freezer, this is preferred since it gets opened significantly less than a standard kitchen freezer. The constant opening and closing of a freezer does not allow for a consistent temperature and can heighten the likelihood of freezer burn.

If you have a large batch of coffee beans, dividing the coffee beans into smaller portions can help guarantee freshness. Please ensure that the smaller portions are kept in airtight containers. 

The Best Grind is A Brew-tiful Thing

You have high-quality coffee beans from your favorite roaster, and now you have the knowledge to ensure they are ground to perfection based on your favorite brewing method. The daily grind might be overwhelming, but finding the best grind for you, whether it’s espresso grind or coarse ground coffee, doesn't have to be. Let's raise a mug to the perfect grind every time.