Brewing coffee is something many of us do every day, but we may not realize how much science there is to producing a good cup of coffee. However, once you understand a few basics about brewing coffee, you can produce an excellent cup every time.

Since its discovery in Ethiopia, coffee has captured man’s attention as we have tried a variety of methods to cook and brew this plant’s fruit. Some early techniques involved pan-frying and boiling the coffee over an open flame. These methods are still used today, but the quest for the "perfect cup of coffee" has yielded a variety of other methods over the years.

Some of the most popular techniques are discussed below. We tried to give you a quick overview of each method, along with some helpful tips. This is by no means a complete discussion on brewing, but it will help you begin to explore.

 

Grinding

The first step in brewing is grinding the beans.

There is really only one appropriate time to grind—immediately before you brew.  We know that many people purchase ground coffee as a convenience, but since drinking coffee is a daily activity in most households, purchasing a grinder is an excellent investment. Remember, coffee begins to lose its flavor the minute you grind it; so the closer you grind it to brewing, the fresher your cup of coffee will be.

In general, the slower the brewing method used, the coarser you need to grind your beans. Beans which are too finely ground for the brewing method in which they are used will expose too much surface area to the heated water and produce a bitter, harsh, "over-extracted" taste. At the other extreme, an overly coarse grind will produce weak coffee.

As far as grinders are concerned, the type you purchase depends on what method of brewing you use for your coffee.  Although there are several methods you can use to grind your coffee, the two most often used are a blade mill grinder or a burr mill grinder.

Blade Mill Grinder:

These inexpensive grinders function similar to a blender, using blades to chop the beans into smaller pieces. If you primarily use automatic drip or pour-over methods, these simple grinders will work. One of the problems with blade mill grinders is they cut the coffee instead of grinding it; this produces a grind that is uneven. The paper filters used in drip brewing methods can compensate for the uneven grind to a certain degree, but a better cup of coffee would be produced with a consistent grind. This would require a more sophisticated grinder such as a burr mill grinder. Since blade mill grinders have no real “settings” to choose grind size, they are not suitable for other brewing methods that require a particularly fine or coarse grind. 

 

A Few General Thoughts on coffee brewing
No matter what method you use, there are some general rules for brewing that help ensure a quality cup of coffee.

Grind coffee immediately before brewing  (see our thoughts on grinding above – this really makes such a difference in your home coffee that it is well worth repeating here). The proper grind should be used for the brewing technique- see the specific brewing method for the type of grind to use.

Use quality water. Because the coffee is 98.85% water, the importance of water quality cannot be overstated. According to the Specialty Coffee Associations standards, water should be fresh, clean and slightly hard. Filtered or spring waters are recommended since tap water can impart undesirable flavors to coffee. Distilled water is not recommended for brewing coffee as it lacks the minerals to bind with coffee’s molecules thus producing a flat tasting beverage.

Use clean equipment. Mineral deposits and residual oils in your equipment will give your coffee a bitter flavor when brewed. To ensure your equipment is free of old coffee, clean it regularly.  We cover different cleaning tips for each kind of brewing equipment below.
 
Buy quality coffee. Since coffee is only made of coffee and water, the quality of the two ingredients is essential to the quality of the final product. When purchasing coffee, look for companies that roast to order when ordering online or look for roasting dates when purchasing in a store. Coffee is an agricultural product- so fresh is always better. Coffee should be purchased shortly after roasting and kept for a maximum of 7 days. 

Store coffee properly.  Although not technically an essential element of brewing, how coffee is stored directly affects flavor. There has been much debate among the coffee industry and consumers as to the best storage method- freezer, refrigerator or room temperature.  Although there are some slight differences in opinions, here is what the coffee industry has generally agreed upon for coffee storage. Up to a one week supply of freshly roasted whole coffee beans can be stored in an airtight canister at room temperature.  A ceramic canister with a vacuum seal is a
good choice - but avoid clear glass. Sunlight and heat are not good for your coffee.  If you end up with a larger supply of coffee then you would use in a week, you may store it in the freezer but there are some precautions you should take to ensure freshness. Put the beans in a zippered plastic storage bag, being careful to remove any extra air. Wrap the plastic storage bag in a layer of aluminum foil or saran wrap.  Only remove the coffee from the freezer, when you are ready to use it in full, do not refreeze your coffee since it will dehydrate it and hasten the flavor decay.  Do not store your coffee in the refrigerator, a place where it is likely to pick up other food odors and flavors.

Brew at the right temperature.  The ideal temperature to brew coffee regardless of the brewing method is between 195 º- 205 º. If the temperature is too low, flavor compounds will not dissolve, resulting in an under-extracted weak beverage. Too high a temperature will cause flavor changes resulting in an over-extracted bitter and astringent beverage.

 

Brewing Methods

Drip Brewing (or gravity brewing)
Overview:  Drip brewing is the method most people are familiar with and can be done with automatic or manual machines. The process for automatic or manual drip brewing involves pouring water over the ground coffee and allowing it to drip through.  Drip brew coffee can make a nice, clean cup of coffee but you need to keep a few things in mind.

• Automatic Machines:  The advantage of the automatic machines is that they do not require you to boil water in a separate container, plus, they can allow you to make coffee quickly and easily for a larger group of people. While there are a wide variety of automatic drip coffee makers available, most of them function the same way.  Coffee grounds are placed in a paper or metal filter inside a funnel, which is set over a glass or ceramic coffee pot. Cold water is poured into a separate chamber, which is then heated up to the boiling point, and directed into the funnel.

 

• Manual Drip Brewing Methods: A time honored tradition, manual drip coffeemakers are still preferred by many over automatic drip coffeemakers, because of the greater control you maintain over the extraction. Manual drip brewing methods involve heating the water separately then pouring the water, using the proper technique, over the roasted, ground coffee beans contained in a filter. Water seeps through the coffee, absorbing its oils and essences then passes through the bottom of the filter. The used coffee grounds are retained in the filter with the liquid falling (dripping) into a collecting vessel such as a carafe or pot. There are several types of manual drip brewing machines on the market; some of the more popular ones are the Chemex brewer, the Bodum Kona Drip coffee brewer and the Melitta Style filter cone.

 

Grind: Typically, coffee used for drip brewing methods (either automatic or manual) should be ground to a medium grind and will have a consistency similar to granulated sugar. You can use a simple blade mill grinder for drip brewing since the filters involved in the process tend to cover up grind inconsistencies, which might have otherwise effected the coffee taste.

Method or Tips:

• Automatic Methods – Since there are so many machines on the market, you will want to follow the instructions for brewing that come with your particular model.  However, there are few things to keep in mind regarding automatic drip brewing that will help you make an excellent cup of coffee.

• Most automatic coffee makers brew at a temperature lower than the Specialty Coffee Association recommendation of 195º- 205ºF. This can cause the coffee to be under-extracted (weak). Look for a machine that specifically brews at the recommended temperature.
• The coffee industry’s recommendation for amount of coffee usage is 2 tbsp per 6 ounces of water.
• Invest in quality paper filters or a permanent gold filter, since cheaper paper filters can both leave a paper residue taste on your coffee and filter out essential oils important to the flavor of the coffee.
• Coffee produced in this method should be consumed immediately and not kept warm on the hot plate provided with the machine.  Brewed coffee is considered an “unstable” substance -meaning the molecular makeup (and flavor) of the beverage begins to change almost immediately after brewing.  Reheating makes it bitter. 
• Look for a machine that meets the coffee industry standard for drip brewing of  4-6 minutes brew time.
• Clean your equipment after every use, plus periodically clean the machine from scale build-up and coffee residues. There are many cleaning products on the market such as Cleancaf that you can run through your machine to remove the build ups. 

• Manual Drip Methods:  As we mentioned above, there are several manual drip machines on the market and each has its own specificinstructions on usage, but here are some general tips on using this method.

• Grind 2 tablespoons of coffee for every 6 ounces of water on a medium grind setting and place into cone filter.
• Boil water on the stove or in an electric kettle until the water reaches approximately 200 º F. When the water stops boiling, allow it to sit for 1 minute so that it will not scorch the coffee. Then pour a small amount of water over the coffee grounds- just enough to wet them without having them float. This is important because it allows the grounds to "bloom," so the desirable coffee elements can be released.
• After this first wetting, simply pour the remainder of the water, soaking the grounds. Once the desired amount of coffee is brewed, dispose of the spent grounds by lifting the filter out of the coffee maker. It’s as simple as that.
• Keep in mind: If the water stalls completely in the grounds; your grind is too fine. If it pours through too fast, and the resulting coffee is weak; then the grind is too coarse. For best results, the water should drip through your coffee for approximately 3 minutes.
• Cleaning this equipment is particularly easy since most of the brewers are dishwasher safe. Check your specific equipment for instructions.

Steep brewing or French pressed coffee
Overview:  Our personal preferred method of brewing, French press, makes a good full-body coffee that tends to be a bit more flavorful than gravity brewed coffee. A cafetière (or French press) is a tall, narrow cylinder with a plunger that includes a metal or nylon mesh filter. Coffee is placed in the cylinder and boiling water is poured in. The coffee and hot water are left in the cylinder for a few minutes (typically 4 minutes) and the plunger is pushed down leaving the filter immediately above the grounds, allowing the coffee to be poured out while the
filter retains the grounds. Since the coffee is steeped then pressed down, water is forced through the grounds, which helps better extract the solubles and oils. The resulting coffee is a bit “muddier” then drip-brewed coffee but less bitter.  The flavor tends to be richer and smoother as well.

Grind: A coarse, even grind is needed. This is best produced using a burr grinder.  

Method:

• Grind your coffee a few notches coarser than filter drip.
• Pull the lid and plunger out of the glass beaker. For every 4 to 5 oz. of water, measure 1 tablespoon freshly ground coffee into the beaker.  You may want to play with this measurement since some people prefer 1.5 tablespoons instead. You can work that out as you get to know your French press.
• Boil water on the stove or in an electric kettle to 200 ºF.  Once boiled, turn off the water and allow it to cool for a minute before pouring.  Pour the water slowly into the carafe, making sure to cover all the grounds to avoid creating a dry patch of grounds in the middle. Don't overfill the press. The water/coffee needs to be just at, or a little below the bottom of the beaker spout.
• Pick up the plunger by the knob so that the lid is down against the screen. Place it lightly on top of the press so that it keeps the heat in, but do not start to push down.
• After 1 minute remove the lid and briefly, stir the coffee with a spoon, replace the top and wait 3 more minutes.
• Hold the lid in place with one hand; carefully start to push the plunger forcing the grounds to the bottom.
• Pushing steadily, the plunger should reach the bottom in 20-30 seconds or less. There should be a small amount of resistance when you plunge. However, if it is too difficult to plunge then your grind is too fine.

Tips:

• When shopping for a French press, purchase one that has a durable cylinder and filter.  Also, keep in mind that you will be cleaning the filter regularly- so look for one that has pieces you can take apart or is one solid plastic piece.
• When cleaning your French press, if you have a filter with multiple parts, make sure to unscrew the filter so that any coffee residue is cleaned after each use. We put our cylinder and filter parts in the dishwasher on a regular basis. This works well and eliminates time wasted hand washing.